EVALUATION OF THE SUSCEPTIBILITY OF FOUR GARDEN EGG (Solanum aethiopicum) VARIETIES TO THE MAJOR FIELD INSECT PESTS BY MENSAH PROSPER ASAMOAH 10524648 THESIS SUBMITTED TO THE UNIVERSITY OF GHANA, LEGON IN PARTIAL FULFILLMENT OF THE REQUIRMENT FOR THE AWARD OF A MASTER OF PHILOSOPHY DEGREE IN ENTOMOLOGY INSECT SCIENCE PROGRAMME UNIVERSITY OF GHANA *Joint Inter-School International Programme for the Training of Entomology in West Africa. Collaborating Departments: Animal Biology and Conservation Science (School of Biological Sciences) and Crop Science (School of Agriculture), College of Basic and Applied Sciences University of Ghana, Legon University of Ghana http://ugspace.ug.edu.gh DECLARATION This is to certify that this thesis, with exception of references, is the result of research undertaken (by, MENSAH PROSPER ASAMOAH, at the Forest and Horticultural Crop Research Centre (FOHCREC) towards the award of Master of Philosophy (M. Phil.) degree in Entomology at the African Regional Postgraduate Programme in Insect Science (ARPPIS), University of Ghana. ……………………… Mensah Prosper Asamoah (10524648) ……………………………… …………………………. Dr. Thomas Buxton Prof. Ken Okwae Fening. (Principal Supervisor). (Co-Supervisor) University of Ghana http://ugspace.ug.edu.gh DEDICATION I dedicate this thesis to my parents Mr. Richard Kusi Mensah and Mrs. Theresah Arhin and to my beloved Grace Patience Affel. University of Ghana http://ugspace.ug.edu.gh ACKNOWLEDGEMENT I am eternally grateful to God for his infinite grace over my life and throughout my studies. I would to express my profound gratitude to the Professor Henrik Skovgard for his immense contribution and also to the Fruit Bunch Vegetable Resilience Programme for offering me the opportunity to complete my M.Phil. at ARPIS by sponsoring this project. Special thanks to my supervisors Dr. Thomas Buxton and Dr. Ken Fening for their advice, support, encouragement, constructive criticisms, remarks and for their critical reading and corrections of my manuscripts My regard to Dr. Maxwell Billah, former Coordinator of the African Regional Postgraduate Programme in Insect Science and all the lecturers at ARPPIS. I wish to thank Dr. Francis Brentu Collison, Director of FOHCREC for allowing me to use the facilities of the center. I am highly indebted Mr. Kobina Danful Fayinkah, and Mr. Isaac Amo and the staff of FOHCREC for assistance and technical support during my work and my stay at FOHCREC. A special thanks to my classmates and friends of ARPPIS for their encouragement and their companionship. University of Ghana http://ugspace.ug.edu.gh TABLE OF CONTENT DECLARATION ............................................................................................................................................... 2 DEDICATION .................................................................................................................................................. 3 ACKNOWLEDGEMENT ................................................................................................................................... 4 ABSTRACT .................................................................................................................................................... 12 CHAPTER ONE ............................................................................................................................................... 1 1.0 Introduction ........................................................................................................................................ 1 1.1 Justification ......................................................................................................................................... 4 1.2 Objectives............................................................................................................................................ 5 1.2.1 Main Objective ..................................................................................................................................... 5 1.2.2 Specific Objectives ........................................................................................................................... 5 CHAPTER TWO .............................................................................................................................................. 6 2.0 Background ......................................................................................................................................... 6 2.1 The biology of garden eggs ..................................................................................................................... 6 2.2 Distribution and varieties of eggplant .................................................................................................... 7 2.3 Use and the nutritional content of eggplants ..................................................................................... 8 2.4 Garden egg production in Ghana ........................................................................................................ 9 2.5 Constraints to eggplant production in Ghana ................................................................................... 10 2.6.1 Major pests of garden eggs ............................................................................................................ 11 2.6.1.1 Aphids ......................................................................................................................................... 11 2.6.1.2 Eggplant fruit and shoot borers (Leucinodes orbonalis) ............................................................. 13 2.6.1.3 Thrips tabaci (Thrips). ................................................................................................................. 18 2.6.1.4 Urentius hystricellus (Eggplant lacebug). .................................................................................... 19 2.6.1.5 Zonocerus variegatus (Variegated grasshopper). ....................................................................... 21 2.6.2. Integrated pest management of pests of garden eggs ................................................................. 23 2.7. The use of host plant resistance in pest management .................................................................... 25 CHAPTER THREE .......................................................................................................................................... 27 3.0 Materials and methods ..................................................................................................................... 27 3.1 Experimental site .............................................................................................................................. 27 3.2. Varieties used and source of seeds .................................................................................................. 27 University of Ghana http://ugspace.ug.edu.gh 3.3. Nursing of garden eggs seedlings .................................................................................................... 31 3.4. Land preparation, field layout and experimental design ................................................................. 31 3.5 Data collection .................................................................................................................................. 32 3.5.2 The level damage caused by insect pests to different varieties of garden eggs. .......................... 33 3.5.3 Assessing the oviposition, larval development and adult emergence of the major fruit and shoot borers in the different varieties of garden eggs. .................................................................................... 35 3.5.3 Assessing the yield and growth parameters of the different varieties of garden eggs. ................ 36 3.5 Data analysis ..................................................................................................................................... 36 CHAPTER FOUR ........................................................................................................................................... 37 4.0 Results ............................................................................................................................................... 37 4.1. The Assessment of the population build-up of the major insect pests of garden eggs on the field. ................................................................................................................................................................ 37 Survey of the major pests that attack the different growing stages of garden eggs. ............................ 54 Table 4: Insects that attack the garden eggs at the vegetative stage in the minor season.................... 57 4.3.0 The level of damage caused by insect pests in the different varieties of garden eggs ................. 67 4.4. Number of shoot and percent shoot damage ................................................................................. 69 4.4.4. Number of flowers and percent flower damage. ......................................................................... 70 4.5.0 Assessing the growth and yield parameters of the different varieties of garden eggs. ................ 73 Susceptibility index ................................................................................................................................. 75 4.5.1 PLANT HEIGHT ................................................................................................................................ 76 CHAPTER FIVE ............................................................................................................................................. 78 Discussion................................................................................................................................................ 78 The major pests that attack the different growing stages of garden eggs. ............................................ 79 5.2 The level of damage caused by insect pests to different varieties of garden eggs. ......................... 81 5.3 Assessing the yield and growth parameters of the different varieties of garden eggs. ................... 82 6.0 CONCLUSION ......................................................................................................................................... 84 6.2 RECOMMENDATION ............................................................................................................................. 85 REFERENCES ................................................................................................................................................ 86 APPENDICES ................................................................................................................................................ 93 University of Ghana http://ugspace.ug.edu.gh LIST OF TABLES Table 1: Production performance of garden egg in the Greater Accra Region ............................ 10 Table 2: Susceptibility index table ................................................................................................ 35 Table 3: Major insect pests of garden egg found during study ..................................................... 37 Table 4: Insects that attack the different growing stages of garden eggs at the vegetative stage in the minor season ........................................................................................................................... 57 Table 5: Insects that attack the different growing stages of garden eggs at the flowering stage in the minor season ........................................................................................................................... 57 Table 6: Insects that attack the different growing stages of garden eggs at the fruiting stage in the minor season ................................................................................................................................. 58 Table 7: Insects that attack the different growing stages of garden eggs at the vegetative stage in the dry season ................................................................................................................................ 61 Table 8: Insects that attack the different growing stages of garden eggs at the flowering stage in the minor season ........................................................................................................................... 61 Table 9: Insects that attack the different growing stages of garden eggs at the fruiting stage in the dry season...................................................................................................................................... 62 Table 10: Insects that attack the different growing stages of garden eggs at the vegetative stage in the major season ............................................................................................................................ 65 Table 11: Insects that attack the different growing stages of garden eggs at the flowering stage in the major season ............................................................................................................................ 66 University of Ghana http://ugspace.ug.edu.gh Table 12: Insects that attack the different growing stages of garden eggs at the fruiting stage in the major season.................................................................................................................................. 66 Table 13: Mean number of shoot and percentage number of shoot ............................................. 70 Table 14: Mean number of flowers and percentage number of damaged flowers ....................... 71 Table 15: Number of Pupae and adult recorded for the different seasons .................................... 72 Table 16: Mean number of fruit, weight and number of damaged fruits ...................................... 74 Table 17: Mean of yield for the different seasons. ....................................................................... 75 Table 18: Susceptibility level of different garden egg varieties. .................................................. 76 Table 19: Mean height of the different varieties ........................................................................... 77 University of Ghana http://ugspace.ug.edu.gh LIST OF FIGURES Figure 1: Experimental field layout .............................................................................................. 32 Figure 2: Mean number of Aphis gossypii during the minor season (October – December) ........ 38 Figure 3: Mean number of Aphis gossypii recorded from February – April. ............................... 39 Figure 4: Mean number of Aphis gossypii recorded from June - July. ......................................... 40 Figure 5: Mean number of Aphis craccivora recorded from October – December. ..................... 41 Figure 6: Mean number of Aphis craccivora recorded in the dry season from February – April. 42 Figure 7: Mean number of Aphis craccivora recorded from June – July. .................................... 43 Figure 8: Mean number of Urentius hystricellus recorded from February – April. ..................... 44 Figure 9: Mean number of Urentius hystricellus recorded from June – July. .............................. 45 Figure 10: Mean number of Thrips tabaci recorded from October – December. ........................ 46 Figure 11: Mean number of Thrips tabaci recorded from February – April ................................ 47 Figure 12: Mean number of Thrips tabaci recorded from June – July. ........................................ 48 Figure 13: Mean number of Zonocerus variegatus recorded from October - December. ............ 49 Figure 14: Mean number of Zonocerus variegatus recorded from February - April.................... 50 Figure 15: Mean number of Zonocerus variegatus recorded from June – July. ........................... 51 Figure 16: Mean number of Leucinodes orbonalis recorded from October – December. ............ 52 Figure 17: Mean number of Leucinodes orbonalis borer recorded from February – April. ......... 53 Figure 18: Mean number of Leucinodes orbonalis recorded from June – July. ........................... 54 University of Ghana http://ugspace.ug.edu.gh Figure 19: Mean number of damaged leaves in the minor raining season. .................................. 67 Figure 20: Mean number of damaged leaves in the dry season. ................................................... 68 Figure 21: Mean number of damaged leaves in the major raining season. ................................... 69 University of Ghana http://ugspace.ug.edu.gh LIST OF PLATES Plate 1: Aphids on the underside of garden egg leaf .................................................................... 12 Plate 2: Adult of L. orbonalis. ...................................................................................................... 14 Plate 3: larvae of L. orbonalis. ...................................................................................................... 15 Plate 4: Pupa of L. orbonalis......................................................................................................... 16 Plate 5: An affected shoot showing signs of drooping. ................................................................ 16 Plate 6: Larva of L. orbonalis feeding in the shoot of garden egg................................................ 17 Plate 7: Larva of L. orbonalis feeding in the fruit of garden egg. ................................................ 17 Plate 8: Thrips tabaci found on the underside of a leaf ................................................................ 19 Plate 9: Nymph of Urentius hystricellus on the underside of a leaf. ............................................ 20 Plate 10: Leaves of garden egg showing yellow-molted patches after feeding by Urentius hystricellus. ................................................................................................................................... 21 Plate 11: Leaves of garden egg dropped off after the feeding activities of Urentius hystricellus. 21 Plate 12: Adult Zonocerus variegatus feeding on leaves of garden egg....................................... 22 Plate 13: Aworoworo garden egg variety ..................................................................................... 28 Plate 14: Yorgbe garden egg variety ............................................................................................. 29 Plate 15: Round garden egg variety. ............................................................................................. 30 Plate 16: Legon 1 variety of garden egg. ...................................................................................... 31 University of Ghana http://ugspace.ug.edu.gh ABSTRACT Field experiments were conducted at Forest and Horticultural Crop Research Center, Kade, Ghana during the 2020 and 2021 cropping season. The susceptibility of four garden egg varieties against the major field insect pest under field conditions. The varieties namely: Aworoworo, Yorgbe, Round garden egg and Legon 1 varieties were laid in randomized complete block design with four replicates. The major insects observed to be causing varying degree of damage were Aphis gossypii, Aphis craccivora, Urentius hystricellus, thrips tabaci Leucinodes orbonalis and lastly Zonocerus variegatus. Insect pest infestation varied among the different varieties. The weekly population build-up of the insects per the different varieties were observed. The population of the insects was fluctuating from the time data collection began to harvesting. For insects such as the Aphis gossypii, Aphis craccivora, their numbers were high whilst insects such as Zonocerus variegatus, Leucinodes orbonalis were recorded in low numbers. In the minor season, Urentius hystricellus was found but was recorded in high numbers in the dry season however, their numbers reduced in the major season. Also, insect pests that attacked the different developmental stages of garden egg were observed. From the study, Aphis gossypii, Aphis craccivora, Zonocerus variegatus, Thrips tabaci and Urentius hystricellus were found to be attacking all the different growth stages of garden eggs. For Leucinodes orbonalis, it was found to be attacking the plant during the flowering and fruiting stages of the plant. In assessing the resistance level in the varieties, none of the varieties was found to be resistant. Based on the susceptibility index, it was found that the Legon 1 variety recorded the highest susceptibility level and was grade as susceptible whilst the Yorgbe variety recorded the least index and was graded as being moderately resistant. The Aworoworo variety and the Round garden egg variety was graded moderately susceptible and moderately resistant respectively. University of Ghana http://ugspace.ug.edu.gh 1 CHAPTER ONE 1.0 Introduction Vegetables are fresh parts of plants which are consumed either raw, cooked, canned or processed (Belitz et al., 2005). They are important component of human diet and their intake is necessary for good health and fitness (Aetiba & John, 2015). Vegetables are rich in vitamin A, vitamin C, folate as well as other nutrients (Muimba-kakonlogo, 2018). Due to the health-protective components found in vegetables, the cultivation of vegetables has become a priority in world food production and distribution systems. This focus on vegetables is particularly important for most people in sub-Saharan Africa as vegetables are nutritious (Muimba-kakonlogo, 2018). Garden eggs like all other vegetables is one of the most consumed vegetables in Ghana and West Africa at large (Owosu, 2012). Garden egg (Solanum aethiopicum) has a botanical association with tomato, pepper and potato and is a member of the family Solanaceae. It is common in Ghana, particularly in the forest area during the major and minor seasons. It is widely cultivated in Ghana (Owusu- Ansah et al., 2001) and over 2 million hectares of land are allocated for its cultivation (FAO, 2007). This crop is consumed on a daily basis in Ghana especially in rural and peri-urban centres. The crop conforms well to high rainfall and hot-wet environments with high yields regardless of the fluctuation in weather pattern (Bonsu, 2017). Its cultivation has become necessary because it provides a source of income for households in rural areas due to the fact that 60% of their income come from garden egg production (Aetiba & John, 2015). It is reported that about 4,350 households in coastal forest and savannah ecological zones in Ghana are heavily engaged in the cultivation of garden eggs, leafy vegetables, tomato, pepper, onion and okra (Horna et al., 2007). There seems to be a variation in the quality attributes of garden eggs such as colour, taste, size and shape. Garden eggs can be deep green, green, white, cream or yellow. Garden eggs have different size University of Ghana http://ugspace.ug.edu.gh 2 however, there seems to be a preference for medium-to-large sizes (Horna et al., 2007). Taste is another important attribute of garden eggs. Garden eggs can have a blunt, sweet or bitter taste. According to Horna et al. (2007), round type garden eggs tend to be bitterer than elongated types. In terms of consumer preference, they normally adjust to what the market offers them however, generally, consumers prefer larger, fresh and white garden eggs but there also exist a market for garden eggs changed colour, aged and lost water (Horna et al., 2007). The cultivation of local varieties of garden eggs help to preserve intra-species biodiversity however in Ghana, there is no specific cultivar grown by farmers as farmers often have a mix of cultivars in their fields (Horna et al., 2007). A study conducted by Horna et al. (2007) showed that farmers gave different names when asked about their preferred varieties with many of the names depicting where they are grown. The common varieties grown include aworoworo, obolo, white beauty, antropo, or yorgbe. Others also gave more descriptive names such as long white, round white, white local, black local or adopt the name of the places they are produced such as kwashie, kpando, techiman and agogo. The round white garden egg can also be called obolo, akutuku, tin toro, kukruwa, Techiman or Kpando. This variety is cropped mainly in the Greater Accra, Central and Volta regions of Ghana. Other varieties such as Aworoworo is commonly grown in Ashanti, Brong Ahafo and Central regions whilst Yorgbe is commonly cropped in the Volta region. Even though much of the cultivation of garden eggs goes to the local market, small amounts are exported to Europe (Horna & Gruère, 2006). According to Bonsu (2017), there was an increase in the exportation of garden egg in Ghana from 500 metric tons in 1996 to 1,867 metric tons in 2003. Again Ministry of Food and Agriculture (MoFA, 2010) reports that the production of garden eggs is estimated at 15 metric tonnes/hectare/year but its production averages 8 metric tonnes/hectare/year. Although the cultivation of this crop has the potential to contribute to poverty alleviation and improve the University of Ghana http://ugspace.ug.edu.gh 3 livelihoods of rural and peri-urban households, pest and diseases seems to be a major constraint in the production of garden egg (Owusu-ansah et al., 2001). Garden eggs are infested worldwide by a vast number of insect pests. According to Owusu-ansah et al. (2001), the pest of garden eggs include Selepa docilis Butler (Lepidoptera: Noctuidae), Scrobipalpa blapsigona Myerick (Lepidoptera: Gelechiidae), Urentius hystricellus Richter (Homoptera: Tingidae), Thrips tabaci Lindemann (Thysanoptera: Thripidae), Bemisia tabaci (Hemiptera: Aleyrodidae), Tetranychus urticae (Trombidiformes: Tetranychidae), Empoasca decipiens (Hemiptera: Cicadellidae), Leucinodes orbonalis Guenee (Lepidoptera: Crambidae), Aphis gossypii Glover (Hemiptera: Aphididae). A study of vegetable pests showed that the most harmful pest in many major egg- producing countries are the shoot and fruit borers (Owosu, 2012). Significant damage is caused by the shoot and fruit borers where the larvae tunnels within fruit thereby reducing the quantity and quality of the marketable fruit yield (Bonsu, 2017). It is estimated that the larvae causes about 70% damage to garden eggs (Netam et al., 2018). Due to damage caused by these insect pests, the use of pesticides to confer protection against insect pests is one of the widely used management method (Owusu-ansah et al., 2001). Their use offers numerous advantages especially in crop production. Despite these benefits, the use of pesticides particularly synthetic insecticides have deleterious effects on humans, beneficial and non-target organisms as well as on the environment. In order to achieve sustainable vegetable production, it is important to find alternative methods that are less harmful to the environment. As a result, integrated pest management (IPM) where different management practices are used is the best in managing insect pests. Control methods including cultural control, physical or mechanical control, biological control, host plant resistance among other control methods are integral part of IPM. Host-plant resistance has been found to interact well with IPM programmes. It represents the ability of crop plants to restrict, retard or overcome University of Ghana http://ugspace.ug.edu.gh 4 pest infestations (Dent et al., 2003). Use of resistant varieties has been found to be important part of insect control because in this control method, the benign environment is not harmed and it interacts well with biological control. It is very useful in countries where holdings are usually small and farmers may not be able to afford other methods of pest control (Selvanarayanan, 2019). 1.1 Justification In Ghana, chemical control is commonly used to manage pests that damage garden eggs. Different types of insecticides including malathion, perfekthion, cypermethrin, diaxocarb, roxion are used to control these pests (Owusu-ansah et al., 2001). Despite the ability of insecticides to minimize insect pest harm, indiscriminate use of insecticides poses several problems. Vegetables are mostly consumed fresh and the use of insecticides to confer protection can have serious health implications on humans, affect beneficial and non-target organisms and also lead to the development of resistance in insects. The use of resistant varieties forms the basis for the integrated management of pests to complement other control methods. The basis on which this IPM structure was developed was through varietal resistance to insect pests. The use of resistant varieties can be effective and its inclusion in insect pest management programs can reduce the effect of pests (Ayyaz et al., 2017). Screening for resistant varieties to insect pest infestation, their ability to cause damage to different growing stages of the crops and also the level of damage associated with insect pest infestation would be the main objective of this study University of Ghana http://ugspace.ug.edu.gh 5 1.2 Objectives 1.2.1 Main Objective To evaluate the susceptibilities of the commonly cultivated garden eggs varieties in Ghana to the major field insect pests. 1.2.2 Specific Objectives 1. To determine the assessment of population buildup of the major insect pests of garden eggs and the different growing stages of the garden eggs they attack i.e. vegetative, flowering and fruiting stage in the field. 2. To determine the level of damage caused by insect pests to the different varieties of garden eggs. 3. To assess oviposition, larval development and adult emergence of the major fruit and shoot borers. 4. To assess the growth and yield parameters of the different varieties of garden eggs. University of Ghana http://ugspace.ug.edu.gh 6 CHAPTER TWO 2.0 Background 2.1 The biology of garden eggs The garden egg Solanum aethiopicum belongs to the solanacaea family and the tribe Solanaea which includes several species such as tomato, pepper, potato among others (Frary, 2007). It is commonly found in Asia and Tropical Africa. Eggplant is a woody plant and develops several branches based on a roughly dichotomic ramification pattern (Frary, 2007). Garden egg is the result of the domestication of one wild and one semi-domesticated solanum species that grow in tropical Africa (Grubben & Denton, 2004). The crop is widely cultivated across the continent especially in West and East Africa (Horna et al., 2006). Garden egg has four main cultivar groups including Gilo, Kumba, Shum, and Aculeatum. According to Horna et al. (2006), the first three are the most important in Africa with the Gilo and Kumba cultivated for their fruits whist the shum is cultivated for their leaves. Species such as Solanum melongena is a bushy plant and reaches a height of between 60cm and 120cm when mature. Frary (2007), reports that variation exist in hairiness, anthocyanins and prickles on the vegetative parts. Its flower type is 5 merous i.e. 5 sepals, 5 petals, 5 stamen however 6, 7 and 8-merous flowers are normally found in globose and round fruited types (Frary et al., 2007). Generally, eggplant is regarded as being autogamous but in warm conditions and open conditions, insects visit the flowers and the allogamy rate is 70% or higher. According to Daunay et al. (2004), the presence or absence of chlorophylls and anthocyanins have been reported to control a variety of fruit colours. It has a fibrous or lignified root system and the leaves are simple, lobed, large and alternate on the stems. They produce fleshy berry fruits which differ in shape (round, intermediate, long, snake-like) and size (Owosu, 2012). The fruit colour is either purple, white, green, yellowish or striped with white and yellow. Eggplant University of Ghana http://ugspace.ug.edu.gh 7 usually undergoes self-pollination, but instances of cross-pollination have been reported and it is recorded to be as high as 48% due to its heterostyly (Owosu, 2012). Garden egg grows best in well drained loam or sandy loam soil with a fair amount of organic matter. Soil pH of 5.8 and 6.5 are best for growth. Usually, moderate amount of fertilizer should be applied to garden egg. 2.2 Distribution and varieties of eggplant S. aethiopicum is a widely cultivated species that exists but have many importance in sub Saharan Africa and are less known (Daunay, 2008). Species such as Solanum melongena is an old world crop that is among the solanaceous species that is cultivated. It is known as eggplant in the United States and aubergine in England and France. However, in its home country i.e. where it has been domesticated for many years and also where the great diversity of this crop exists, it is called brinjal (Daunay, 2008). Arabic traders introduced Solanum melongena var to South Europe and the Mediterranean area (Aetiba & John, 2015). The crop is widely grown and common in the temperate and tropical regions of Asia, Middle East and the parts of the Mediterranean basin but presently, it is cultivated worldwide. According to Daunay (2008), evidence points to the fact that based on studies on morphometrics, crossability, seed coat scanning electron microscopy, leaf isozymes, and seed protein electrophoresis on a large number of accessions showed that the ancestral forms of S. melongena emerged from Africa tropics and the Middle East. In these regions are found the closest wild relatives of S. melongena which are part of the S. incanum aggregate. The S. incanum aggregate includes four groups namely University of Ghana http://ugspace.ug.edu.gh 8 1. Group A (S. campylacathum) which is found in the East African tropics 2. Group B (S. delagoense) whi is distributed in South-Eastern Africa 3. Group C (S. incanum sensu stricto) is found in North-Eastern Africa and Middle East 4. Group D (S. lichtensteinii) is found in South-East Africa. Garden eggs derive its name from the shape of the fruits which are white in colour and looks very much like chicken eggs. Under species melongena, three varieties exist. These include the egg- shaped cultivars which are grouped under var. esculentum (common eggplant), var. Serpentinum which is the long and slender type and lastly var. depressum (dwarf eggplant) which are small (Aetiba & John, 2015). 2.3 Use and the nutritional content of eggplants It is reported that Solanum melongena var is one of the most consumed vegetable in Ghana and West Africa at large (Owosu, 2012). The unripe fruit of eggplant is used to prepare a variety of dishes around the world. This crop is consumed on a daily basis in Ghana especially in rural and peri-urban centres. It also provides a source of income for households in rural areas due to the fact that 60% of their income come from garden egg production (Aetiba & John, 2015). Again, garden egg has medicinal purposes. Generally, garden egg is regarded as a low calorie vegetable. Garden egg contains vitamins, minerals, proteins, fiber and other important nutrients such as phenolic compounds and flavonoids which are good for human health (Daunay, 2008). The phenolic compounds such anthocyanins and phenolic acids eggplant contain including alkaloids have biological and pharmaceutical properties (Gürbüz et al., 2018). The Eggplant has been used in the traditional medicines because of its high level of alkaloids. Its tissue extracts are used for the treatment of asthma, bronchitis, cholera, and dysuria and fruits and leaves are beneficial in University of Ghana http://ugspace.ug.edu.gh 9 lowering blood cholesterol. Recently, it has been shown that eggplants also possess antimutagenic properties (Kole et al, 2010). 2.4 Garden egg production in Ghana The African garden egg is one of the most important vegetables in Ghana and West Africa. This crop that is particularly diverse in Ghana is not only consumed on a daily basis by rural and urban families but also represents the main source of income for many rural households in the country (Bonsu, 2017). According to Daunay (2008), an estimated 31 million tons of eggplant was produced worldwide. From this data, China had the highest production amounting to 16.5 million, and India produced about 8.2 million tons of eggplant. Countries such as Egypt produced 1.1 million tons, Turkey produced 900,000 tons where as Japan produced 400,000 tons. However, according to Taher et al. (2017), current data suggests that the annual production of eggplant is around 50 million tons with a net value of US$10 billion from the production eggplant which makes it one of the economically important solanaceous crop after potato, tomatoes, pepper and tobacco. Over 90 percent of eggplant is produced in seven countries including China, Egypt, Turkey, Japan (Weese & Bohs, 2010). In Ghana, national production is around 30,000 tons exact number are not available for the whole country. Data exists for the Greater Accra Region where urbanization has contributed to a steady decline in the total output, areas cultivated and yield University of Ghana http://ugspace.ug.edu.gh 10 Table 1: Production performance of garden egg in the Greater Accra Region Year Production (t) Area (ha) Yield (t/ha) 1993 10,100.00 3,100.00 3.26 1994 12,250.00 3,140.00 3.90 1995 1,296.40 280.00 4.63 1996 Not available Not available Not available 1997 6390.00 809.00 7.89 1998 1613.00 461.00 2.62 1999 1527.00 509.00 2.25 2000 1470.00 491.00 2.19 2001 916.00 322.00 1.80 2002 962.00 322.00 1.80 2003 531.00 178.00 1.79 2004 570.00 190.00 1.97 Source: Horna et al, 2007 According to Horna et al. (2007), garden egg is a profitable venture especially in the Greater Accra Region, where production yields more and prices are high and fluctuates a great deal in the year. Some producers are close to the Volta River Dam and can still produce even in the dry season as result, they are able to get high returns from their venture. 2.5 Constraints to eggplant production in Ghana There many constraints faced by farmers in the production of garden eggs including the fact that it is labour intensive especially during the harvesting period, limited amount of fertilizer and pesticides but prime among is the insect pest infestation. Due to the fact that garden eggs have a relatively long growth period, it remain exposed to pests, weeds and diseases than other vegetables. Garden egg is attacked by numerous pests including mites, whiteflies, aphids, eggplant fruit and University of Ghana http://ugspace.ug.edu.gh 11 shoot borer, thrips, leafhopper, spotted beetles, leaf roller, stem borer, blister beetles among other pests (Taher et al., 2017). It has been reported that about 146 species of insect pests are present on eggplant of which 58 species are known to feed on the different parts of the plant. Among these insects, the most important and damaging insect pest is the eggplant fruit and shoot borer (Leucinodes orbonalis) (Kotey et al., 2013). The larvae of this insect feed inside the fruits and shoots leading to withering and drying of the shoots and fruits making it not wholesome for consumption (Owosu, 2012). Other important pests include the eggplant budworm which oviposits in the flowers. Other insects such eggplant lacebug, variegated grasshopper among other insects are known to be defoliators of garden egg (Owusu Ansah et al., 2001). 2.6.1 Major pests of garden eggs 2.6.1.1 Aphids These are small insects that exist in groups on the underside of leaves, flower buds and on young shoots. Adult aphids have a colour which varies from ash-gray, black, brown, and green to yellow. On the dorsal side of the body, there exist a black-coloured cornicles (Bonsu, 2017). Winged and wingless forms of aphids exist. Wingless forms are more common with the winged forms produced under high population density conditions among others (Aetiba & John, 2015). Aphids do not lay eggs however they reproduce through parthenogenesis and are viviparous. Each adult female can produce 20 nymphs a day which matures into adult in a week (Srinivasan, 2009). They are r- strategists that tend to be mobile and reproduce rapidly. Generally, r-strategists utilizes the resources available to them making them achieve the pest status leading to the destruction of the host before dispersing. According to Wakil et al. (2017), aphids damage crops in three ways by sucking the sap from the plant which weakens the plant leading to lower quantity and quantity of University of Ghana http://ugspace.ug.edu.gh 12 fruit. Secondly, they produce honeydew which can cover the leaves and fruits. The sugary substance produced as a result makes it suitable for the growth of sooty mold fungi. On the foliage, this sooty can be thick that it can reduce the photosynthetic activity on the leaves resulting in poor quality and quantity of fruit. The third and costly type of damage that aphids are efficient vectors of a number of plant viruses. Plate 1: Aphids on the underside of garden egg leaf University of Ghana http://ugspace.ug.edu.gh 13 2.6.1.2 Eggplant fruit and shoot borers (Leucinodes orbonalis) Leucinodes orbonalis belongs to the family Pyralidae and genus Leucinodes. This insect occurs in tropical Asia. The adult lay 80 to 253 eggs usually on foliage (Owosu, 2012). Laying of eggs occurs in the night usually on the lower surfaces of young leaves, stems, and flowers among others. Eggs of L. orbonalis are normally elliptical, flat and about 0.5mm in diameter (Owosu, 2012). The eggs when laid are creamy white but turns red before they hatch. Pre oviposition period is 1.2 and 2.1 days whilst oviposition periods are 1.4 and 2.9 days. In 3 to 6 days, eggs hatch and larvae bore into soft shoots, flowers or fruits (Owosu, 2012). Although there are reports of larvae undergoing 6 instar stages, the larvae usually go through 5 instars. During the larval stage, the larvae go through five instars. The larvae measures about 18 to 23mm in length. Pupation occurs in silken cocoons on plant debris or fallen leaves on the soil surface near the base of the plant. Depending on temperature, the pupal period lasts between 6 to 17 days (Owosu, 2012). The adults are known to emerge at night. They measure about 20 to 22mm. Females are somewhat bigger than the males and the females have abdomen that looks pointed and curled upwards. Males on the other hand have a blunt abdomen. The adult moth is white but there is a pale brown or dark spots on the thorax and abdomen. The moth has white wings with pink or blue spots and have small hairs on the apical and anal margins. There exists a number of black, pale and light brown spots on the forewings (FAO, 2003). The larvae is considered as the most damaging stage of the insect. The larvae contributes more than 75% damage to garden eggs reducing its quality thereby affecting its price considerably (FAO, 2003). At night, the adult comes to lay eggs on the underside of leaves, stems, flower buds or calyces of the fruit. After hatching, the larvae bores into adjacent shoots, fruits or flower. After boring into shoots or fruits, they begin to feed within the fruit or shoot and block the entrance hole University of Ghana http://ugspace.ug.edu.gh 14 with frass. Feeding activity of the larvae leads to the wilting of the young shoots. The damaged shoots drop off altering plant growth and as a result reducing the size and the number of fruits. Plants produce other shoots to compensate for lost shoots however plants take longer period to produce flowers and fruits (Biswas et al., 2018). It should be noted that, the larvae prefer the fruit to shoots and damage done is not reversible. Plate 2: Adult of L. orbonalis. University of Ghana http://ugspace.ug.edu.gh 15 Plate 3: larvae of L. orbonalis. University of Ghana http://ugspace.ug.edu.gh 16 Plate 4: Pupae of L. orbonalis. Plate 5: An affected shoot showing signs of drooping. University of Ghana http://ugspace.ug.edu.gh 17 Plate 6: Larva of L. orbonalis feeding in the shoot of garden egg. Plate 7: Larva of L. orbonalis feeding in the fruit of garden egg. University of Ghana http://ugspace.ug.edu.gh 18 2.6.1.3 Thrips tabaci (Thrips). Thrips are polyphagous species, and it is known as pests of Cucurbitaceae and Solanaceae (Capinera, 2020). They are very small insect about 1mm long and are brownish-yellow in colour (FAO, 2003). They have two pairs of long narrow wings which are fringed around the edges with hair-like structures. Nymphs are pale yellow, almost similar to adults but smaller and wingless (Capinera, 2020). Thrips are active during the day and can be found on the underside of leaves or at the base of plants however pupae are found in the soil (FAO, 2003). They lay eggs in notches of up to 100 eggs in the stem of young plants and in tissue of leaves. Eggs takes 4-10 days to hatch. Although thrips feeds on cucurbits, but occasionally infests garden eggs. They are known to cause damage to garden eggs in the dry season. Thrips are known to feed on tomato, potato, pepper, watermelon, cucumber among others. Damage caused by thrips is done on the underside of leaves where they look brown and dried up. They are responsible for feeding on the sap of leaves and in heavy infestation can cause stunted growth of the leaves, wilted shoots and can reduce fruit size and possibly cause death of the plant (FAO, 2003). Although, feeding usually occurs on the foliage, scars, deformities and abortion have been reported in the fruits (Capinera, 2020). University of Ghana http://ugspace.ug.edu.gh 19 Plate 8: Thrips tabaci found on the underside of a leaf 2.6.1.4 Urentius hystricellus (Eggplant lacebug). It is a small bug (about 3 mm in length), brownish in colour. Its body is covered with spines and the wings show a distinct lace-like appearance. Nymphs resemble adults, but are initially wingless, developing wings as they grow. Both adults and nymphs are usually found in groups on the underside of leaves. They suck sap from the leaves causing whitish to yellowish mottled patches on the leaves. In case of serious infestations the leaves turn entirely yellow and drop off. Attacked leaves are speckled with small black shiny spots, which are the faeces of the bugs. Damage to leaves is done by both adults and nymphs however, nymphs are localized whilst adults fly to other plants to cause damage. University of Ghana http://ugspace.ug.edu.gh 20 Plate 8: Nymphs of Urentius hystricellus on the underside of a leaf. University of Ghana http://ugspace.ug.edu.gh 21 Plate 9: Leaves of garden egg showing yellow-molted patches after feeding by Urentius hystricellus. Plate 10: Leaves of garden egg dropped off after the feeding activities of Urentius hystricellus. 2.6.1.5 Zonocerus variegatus (Variegated grasshopper). Zonocerus variegatus is a species that is native to tropical West and Central Africa. In Ghana, Ivory Coast, Nigeria, Congo Brazzaville, Southern Benin, and the Sahel region, it is a significant agricultural pest. It is a polyphagous insect that feeds on a variety of crops. Both nymphs and mature Zonocerus variegatus cause crop damage, most notably cassava, groundnuts, and vegetables, and it has been linked to the spread of mosaic viruses of cowpea and okra. They are University of Ghana http://ugspace.ug.edu.gh 22 active during the day and spend the night and cooler hours of the day resting on crop leaves. Although it primarily feeds on cassava, this pest has also been found to feed on vegetables, including garden eggs, where it can cause a 25–80% yield loss (Kekenou et al., 2005). It is considered an important pest in Nigeria, Ghana, and the Ivory Coast, among other countries, due to the damage it causes to crops. The adult and nymph of the Zonocerus variegatus chew on crop leaves reducing the area available for photosynthesis. Plate 11: Adult Zonocerus variegatus feeding on leaves of garden egg. University of Ghana http://ugspace.ug.edu.gh 23 2.6.2. Integrated pest management of pests of garden eggs Garden eggs is known to have a long growth period and as a result, remains in the field for a long time. This exposes the crop to variety of insect pests, diseases among others. Consequently, the use of one control method would not be ideal to take care of the numerous pests that attack this crop. The use of a particular management strategy to control a particular insect would not be able deal with other pests. Therefore, integrated pest management that require a holistic approach to controlling insect pests should be adopted. This method works better when together than separate. Integrated pest management approach involves methods such as cultural, biological, mechanical, chemical control among many other control methods. Cultural practices such as harvesting of fruits promptly, removal of infested shoots and shoots and picking and crushing larvae or pupae of insect pests can help to control them. For eggplant shoot and fruit borers, several management practices have been employed to manage the fruit and shoot borers. This includes the breaking clods of the soil before transplanting. This help to reducing population. Also avoid planting over-aged seedlings. Seedlings should not remain in the nursery for too long as they become weak due to competition for space, light and nutrients (FAO, 2003). Seedlings when crowded can be a breeding ground for fruit and shoot borer. Sanitation practices such as cleaning the soil to remove fruit and shoot borer pupae should be encouraged (Dent, 2003). Intercropping with herbs such as Nigella sativa, Foeniculum vulgar, Coriandrum sativum help to reduce infestation of fruit and shoot borer. Again, natural enemies help to reduce insect pest of garden eggs. For instance studies has shown Trathala flavor-orbitalis an ichneumonid wasp to be a parasitoid of eggplant fruit and shoot borer. Trichogramma chiloni, Eriborus sinicus, Cotesia sp. have also been reported to be a parasitoid of eggplant fruit and shoot borers (FAO, 2003). For thrips, use of resistant varieties is one way of controlling thrips infestation. Other methods include mulching which has the ability of reducing University of Ghana http://ugspace.ug.edu.gh 24 damage caused by thrips. White plastic or silvery plastic mulch has the potential to reduce thrips infestation however, straw mulch can be used. Flooding the field can also be used to manage thrips. This has the potential of reducing thrips population presumably drowning thrips pupae in the soil. The use of insecticides is also recommended for the control of thrips however its use should be regulated because there is strong indication that melon thrips abundance and damage are increased by the application of some insecticides (Capinera, 2020). Natural enemies such as the predatory mite, Amblyseius cucumeris feeds on various thrips species. The lacewings, Chrysopa carnea is the most common species that feed on thrips (FAO, 2003). For eggplant lacebug, the use of synthetic insecticides have shown to be effective against this insect. Also neem products are effective against eggplant lace bug. The management of aphids in garden eggs production requires an integrated approach. This includes cultural control such as proper farm sanitation and intercropping. Plant debris left in the field after harvest may serve as breeding grounds for aphids. It is therefore important to remove all sources infestation as possible Intercropping rows of another crop or planting a barrier crop around garden egg field helps to reduce aphid infestation. Use of insecticides is another way of controlling aphid however its use should be regulated as it has effects on other natural or beneficial organisms. Some botanical extracts have also been reported to control aphids. These include neem kernel oil, lemon grass extracts among others. Use of resistant varieties is another method that forms an integral part of IPM. This method interacts with other control methods and has no effect on the environment. Even though, this is difficult to develop as resistant varieties are not resistant to all pests, this method is one of the best environmentally safe strategy University of Ghana http://ugspace.ug.edu.gh 25 2.7. The use of host plant resistance in pest management Over the years, many efforts have been channeled towards the development of insect resistant varieties. Using resistant varieties are compatible and can act synergistically with other control measures such as cultural, biological, mechanical control among others. Host plant resistance has been identified as one of the self-perpetuating and cost-effective methods used in integrated pest management programmes. This method has provided the basis on which most integrated pest management structure are built. Resistance in a crop cultivar is enhanced through the presence of biophysical or biochemical factors (Dent, 2003). Use of resistant varieties have been found to be important part of insect control because in this control method, the benign environment is not harmed and it interacts well with biological control. Again, use of resistant varieties are very useful in countries where holdings are usually small and farmers may be able to afford other methods of pest control. Use of resistant varieties may also enhance the efficacy of insecticides Since the 1800, many efforts have led to the development of insect resistant varieties. Early maturing varieties of wheat were developed to evade damage by the Hessian fly, Mayetiola destructor (Say) in 1788 (Selvanarayanan, 2019). The discovery of the wheat cultivar “Underhill” in New York as resistant to Hessian fly was also made. “Winter Majetin” and “Northern Spy” which apple varieties were identified to be resistant to woolly aphid Eriosoma lanigerum (Hausmann). In rice production, the International Rice Research Institute (IRRI) in Philippines developed varieties that are resistant to the key insect pests and diseases of rice. Consequently, varieties such University of Ghana http://ugspace.ug.edu.gh 26 as IR36 was identified to be resistant the brown planthopper, green leafhopper, stem borers, bacterial blight, tungro among many other pests and diseases (Selvanarayanan, 2019). University of Ghana http://ugspace.ug.edu.gh 27 CHAPTER THREE 3.0 Materials and methods 3.1 Experimental site The experiment was conducted at the Forest and Horticultural Crop Research Centre (FOHCREC) located within the forest agro-ecological zone in the eastern region of Ghana. FOHCREC is located at Okumaning-Kade, in the Denkyembour district in the Eastern of region of Ghana. The centre is located (06° 05’N; 0° 05W; 90 km NW) in the semi-deciduous forest agro-ecological zone. It is characterized by a semi-equatorial climate with a bimodal rainfall ranging between 1200-1500 mm. The major rainy season starts from mid-March to July with a peak in June-July, with the minor rainy season from September to mid-December with a peak in September-October. However, the region experiences some rainfall every month of the year. The mean annual temperature range at this location is 25-38°C. The Relative Humidity is around 70-80% for most parts of the year. 3.2. Varieties used and source of seeds The varieties of garden eggs used were local varieties which were obtained from the Forest and Horticultural Crop Research Centre. The varieties used for this study include Aworoworo: this variety is elongated and has a tear-drop shape. It is commonly grown in the Ashanti, Central and Volta regions of Ghana (Horna et al., 2007). University of Ghana http://ugspace.ug.edu.gh 28 Plate 13: Aworoworo garden egg variety Yorgbe: this variety look very similar to aworoworo but is bigger and assumes a more triangular shape. It is broader at the stem insertion and narrower at the other end (Horna et al., 2007). University of Ghana http://ugspace.ug.edu.gh 29 Plate 14: Yorgbe garden egg variety Round garden egg: based on the area, the round garden egg can be called akutuku, tin toro, kukruwa, Techiman, Kwashie, or Kpando irrigated variety (Horna et al., 2007). University of Ghana http://ugspace.ug.edu.gh 30 Plate 15: Round garden egg variety. Legon 1 variety: this is an advanced line bred at the University of Ghana, Legon, hence the name. It is one of the widely cultivated variety and it is an interspecific cross between the common eggplant and the African garden egg (Horna et al., 2007) University of Ghana http://ugspace.ug.edu.gh 31 Plate 16: Legon 1 variety of garden egg. 3.3. Nursing of garden eggs seedlings Seed trays were used to nurse the seeds of all the varieties of the garden eggs. Watering was done manually with a watering can, twice daily to keep the soil moisture constant. Nursery practices were carried out until seedlings were transplanted onto the field. 3.4. Land preparation, field layout and experimental design The experimental field was weeded and ploughed before lining and pegging was done. The field was laid out in a randomized complete design (RCBD) with four treatments. Each plot measured 3.2m by 3m. Each plot had a total of 20 plants. University of Ghana http://ugspace.ug.edu.gh 32 Figure 1: Experimental field layout Normal agronomic practices including watering, fertilizer application, and weed control were carried out on the field. Weeding was done manually at two or three weeks interval. N-P-K 15-15- 15 was be applied to the plants at 4 weeks and 8 weeks after planting. No Insecticides were sprayed throughout the period of the study. 3.5 Data collection 3.5.1. The Assessment of population buildup of the major insect pests of garden eggs and the different growing stages of the garden eggs they attack i.e. vegetative, flowering and fruiting stage in the field. Two weeks after transplanting, data on insect pests that visit the garden egg plants were taken. This was done by visual observation and setting of yellow pan traps for insect collection. A detergent was dissolved in the water to reduce the surface tension of the water and enhance the University of Ghana http://ugspace.ug.edu.gh 33 arrestant effect of the trap. Visual observation was carried out in the morning between 6:00am and 8:00am on sampling days. The content of the trap from each plot were sieved separately through white nylon cloth. Data was collected until harvest, to see how the pest population build up per the various varieties. The major insect pest that attack the different developmental stages of garden eggs was surveyed. As a result, data from the vegetative stage through to the fruiting stage was surveyed. 3.5.2 The level damage caused by insect pests to different varieties of garden eggs. Data was taken to assess the level of injuries done to the different varieties of garden egg. Damage caused to the leaves, shoots, flowers and fruits were taken throughout the period. For the determination of damage caused to leaves, the number of new leaves produced by garden eggs every 14 days was taken and expressed over the number of damaged leaves. Leaves were considered damaged when about 75% of leaf was missing (Owusu-ansah et al., 2001). Percentage leaf damage was calculated using the formula below 𝑃𝐿𝐷 = 𝑇𝐿𝐷 𝑇𝐿14 ∗ 100 where PLD is the percentage of leaf damage, TLD is the total number of damaged leaves and TL14 is the total number leaves produced in 14 days. Also, the average number of shoots and damaged shoots were recorded. Shoots here included the leaves and branches that were damaged as a result of the borer activities. Shoots were considered damaged based on the following; i. presence of frass University of Ghana http://ugspace.ug.edu.gh 34 ii. emergent holes on the shoots iii. Leaves and branches losing their freshness and drooping. Percentage shoot damage was calculated using the using the formula below 𝑃𝑆𝐷 = 𝑇𝑆𝐷 𝑇𝑆14 ∗ 100 TSD is the total number of damaged shoot, TS14 is the total number shoot counted in 14 days and PSD is the percentage of shoot damage. The flowers were also classified as damaged or undamaged when they could not develop into fruit and found either on the plant or fallen on to the ground (Owusu-ansah et al., 2001). To determine damage caused to fruits, fruits were collected and sorted into damaged and undamaged categories. A fruit was considered damaged based on i. The presence of feeding scar. ii. Frass. iii. Emergent hole in it. The damaged fruit were dissected and examined for the presence of fruit borer larvae. In order to prevent cutting through larvae in fruits that showed no visible sign of infestation, fruits were kept for some time until larvae emerges to pupate. Based on the damage caused to the fruit, the scale below was used for grading the level resistance as used by Selvanarayanan (2019) University of Ghana http://ugspace.ug.edu.gh 35 Table 2: Susceptibility index table Damage Level Rating No damage Highly resistant 0 – 10.0 Resistant 10.1 – 20.0 Moderately resistant 20.1 – 30.0 Moderately susceptible 30.1 – 40.0 Susceptible 40.1 and above Highly susceptible 3.5.3 Assessing the oviposition, larval development and adult emergence of the major fruit and shoot borers in the different varieties of garden eggs. Fruits were harvested three times in each of the seasons. In order to prevent cutting through larvae in fruits that showed no visible sign of infestation, fruits were kept for some time until larvae emerged to pupate. Data on the number of exit holes on the fruits were taken for the different varieties of garden eggs. Also, Larvae were reared until they reached adult stage. Observation was made on the oviposition preference, larval development and adult emergence. Percentage adult emergence per the varieties was determined. Percent fruit infestation was calculated using the formula (%) = Number of infested fruits Number of total fruits ∗ 100 University of Ghana http://ugspace.ug.edu.gh 36 3.5.3 Assessing the yield and growth parameters of the different varieties of garden eggs. Data on yield of the different varieties of garden eggs were collected. Data for the yield that was taken included i. the number of fruits produced per plant ii. weight of fruits produced per plant iii. plant height Yield was calculated using the formula Fruit yield/ha = 1000 𝐴𝑟𝑒𝑎 ℎ𝑎𝑟𝑣𝑒𝑠𝑡𝑒𝑑 * fruit yield/plot (John & Aetiba, 2015). 3.5 Data analysis The Data collected from the field was entered in Microsoft excel and analyzed with Gen Stat Statistical Package (12th Edition). The data involving count was transformed with square root data transformation and Analysis of variance was run at 95% confidence. The means were separated with LSD test at 5% level of significance. University of Ghana http://ugspace.ug.edu.gh 37 CHAPTER FOUR 4.0 Results 4.1. The Assessment of the population build-up of the major insect pests of garden eggs on the field. The study was carried out in three seasons, the minor raining season (October to December 2020), the dry season (February to April 2021) and then the major raining season (June to July 2021). The major insect pests found during the study were Cotton aphid (Aphis gossypii), Black bean aphid (Aphis craccivora), thrips (Thrips tabaci), eggplant lacebug (Urentius hystricellus) and eggplant fruit and shoot borers (Leucinodes orbonalis). The Aphis gossypii, Aphis craccivora, Thrips tabaci, Leucinodes orbonalis were found in all three seasons whilst the Urentius hystricellus was found only in the dry and major seasons (Table 4.1). Table 3: Major insect pests of garden egg found during study Insects Present/Absent Minor season Dry season Major season Aphis gossypii + + + Aphis craccivora + + + Thrips tabaci + + + Urentius hystricellus - + + Leucinodes orbonalis + + + NB: + (Present) and (- absent) University of Ghana http://ugspace.ug.edu.gh 38 4.1.1. Aphis gossypii The population buildup of Aphis gossypii for the three seasons is shown in Fig 2 - 4. The population of Aphis gossypii was found to be fluctuating from the first week of sampling through to the seventh week. For the minor season, as shown in Fig 2, the Legon 1 had significantly higher infestation than the other varieties. The Legon 1 variety recorded the highest number (283.3) in the fourth week, but the numbers reduced in the subsequent weeks. On the other hand, the round garden egg variety showed the least infestation of aphid with the least number recorded in the sixth week (16.7). The Aworoworo variety and Yorge variety also recorded high numbers of 86.8 and 154.5 respectively. Figure 2: Mean number of Aphis gossypii during the minor season (October – December) 0 50 100 150 200 250 300 0 1 2 3 4 5 6 7 8 M EA N N U M EB R O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKS Aworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 39 During the dry season, as shown in Figure 3, the Yorgbe variety recorded the highest mean number of the Aphis gossypii (535.5) with the highest being recorded in the third week (257.5). The round garden egg variety recorded the lowest number (364.2) of Aphis gossypii with lowest number recorded in the fifth week. The numbers of the Aphis gossypii was found to be fluctuating from the first week till the 7th week. Figure 3: Mean number of Aphis gossypii recorded from February – April. During the major season, as shown in Figure 4, the Legon 1 variety recorded the highest number of Aphis gossypii with an overall number of (201.6) and the highest number recorded in the fourth week (62.5). Also, the Yorgbe variety was the variety that recorded the least number of Aphis gossypii with an overall number of (90.8) and least number recorded in the third week (10). 0 50 100 150 200 250 300 0 1 2 3 4 5 6 7 8 M EA N N U M EB R O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKS Aworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 40 Figure 1: Mean number of Aphis gossypii recorded from June - July. 4.1.2 Aphis craccivora The population buildup of Aphis craccivora for the three seasons is shown in Fig 5 - 7. Aphis craccivora was found in the minor season i.e. October – December. During the minor season, the population was found to be fluctuating from week one to the time of harvesting (Fig 5). Generally, the Legon 1 variety recorded the highest number of Aphis craccivora with an overall number of (1252.0) and the highest number recorded in the fourth week (455.0). Also, the Yorgbe variety was the variety that recorded the least number of Aphis craccivora with an overall number of (41.3) and least number recorded in the fifth week (Fig 5). 0 10 20 30 40 50 60 70 0 1 2 3 4 5 6 7 8 M EA N N U M EB R O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKS Aworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 41 Figure 5: Mean number of Aphis craccivora recorded from October – December. Aphis craccivora was found in the dry season i.e. February – April. The population recorded for 6 six plants per treatment per week is shown in figure 6. Consequently, the number of Aphis craccivora was found to be fluctuating from the first week to the time of 7th week. The dry season, (i.e. February– April) also saw the Legon 1 variety recording the highest number of Aphis craccivora with an overall number of (337.7) and the highest number recorded in the sixth week (243.3). The Aworoworo variety was the variety that recorded the least number of Aphis craccivora with an overall number of (29.2). The other varieties i.e. the Yorgbe and round garden egg variety recorded an overall mean number of 148.0 and 145.0 respectively (Fig. 6). 0 50 100 150 200 250 300 350 400 450 500 0 1 2 3 4 5 6 7 M EA N N U M EB R O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKS Aworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 42 Figure 6: Mean number of Aphis craccivora recorded in the dry season from February – April. During the major raining season (i.e. June – July), on the other hand, however, the round garden egg variety recorded the highest number of Aphis craccivora with an overall number of (234.2) and the highest number recorded in the sixth week (71.7). Also, the Legon 1 variety was the variety that recorded the least number of Aphis craccivora with an overall number of (35.3) and least number recorded in the second week (0.3). 0 50 100 150 200 250 300 0 1 2 3 4 5 6 7 8 M EA N N U M EB R O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKSAworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 43 Figure 7: Mean number of Aphis craccivora recorded from June – July. 4.1.3 Urentius hystricellus Urentius hystricellus is another pest that was found during the study however, this pest was not found in the minor season during which the study was conducted. It was found in both the dry (February – April) and major seasons (June - July). During the dry season, the round garden egg variety recorded the highest mean number (1176.5). The Aworoworo variety recorded the lowest mean number (371.5) of Urentius hystricellus with lowest number recorded in the second week (8.9). The numbers of the Urentius hystricellus was found to be increasing from the first week until the 7th week. 0 10 20 30 40 50 60 70 80 0 1 2 3 4 5 6 7 8 M EA N N U M EB R O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKS Aworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 44 Figure 8: Mean number of Urentius hystricellus recorded from February – April. In the major season generally, the numbers of the Urentius hystricellus were found to be increasing from the first week, but it was observed that their numbers reduced in the 7th week (Fig 9). The Aworoworo variety recorded the highest number (8.3). The round garden egg variety on the other hand recorded the lowest mean number (3.3) of Urentius hystricellus. 0 100 200 300 400 500 600 0 1 2 3 4 5 6 7 8 M EA N N U M EB R O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKS Aworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 45 Figure 9: Mean number of Urentius hystricellus recorded from June – July. 4.1.4 Thrips tabaci The population of thrips was found to be fluctuating for all the varieties over the weeks for the three seasons. Figures 10 - 12 show the number of Thrips tabaci recorded during the periods of study. During the minor season (Fig 10), the Aworoworo variety recorded the highest number of Thrips tabaci with highest being recorded in the sixth week (7.8). The round garden egg variety however recorded the least number of Thrips tabaci with an overall number of (8.2). 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0 1 2 3 4 5 6 7 8 M EA N N U M EB R O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKS Aworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 46 Figure 10: Mean number of Thrips tabaci recorded from October – December. During the dry season (Fig 11), however, the round garden egg variety recorded the highest number of Thrips tabaci with highest being recorded in the sixth week (3.3) with an average mean number of (8.5). The Aworoworo variety on the other hand recorded the least number of Thrips tabaci (4.0). 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 M EA N N U M EB R O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKS Aworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 47 Figure 11: Mean number of Thrips tabaci recorded from February – April In the major season, generally, the Aworoworo variety recorded the highest number of Thrips tabaci with average number of (13.3) (Fig 12). The lowest number (0.3) of Thrips tabaci was recorded in the first week. Also the Yorgbe variety recorded the least number of Thrips tabaci with an overall number of 11.7. However, the Legon 1 variety and the round garden variety recorded an average number of 12.2 and 13.0 respectively (Fig 12). 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 M EA N N U M EB R O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKS Aworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 48 Figure 12: Mean number of Thrips tabaci recorded from June – July. 4.1.5 Zonocerus variegatus In the minor season, the Legon 1 variety recorded the highest number of Zonocerus variegatus with mean number of 3.3 whilst the Aworoworo variety recorded the least number of Zonocerus variegatus with average number of 0.8. During the period, the number of Zonocerus variegatus was found to be fluctuating from the 1st week to the 7th week. The highest peak was recorded by Legon 1 variety in the 5th week. The Figure 13 below shows the population trend of Zonocerus variegatus in the minor raining season. 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 0 1 2 3 4 5 6 7 8 M EA N N U M EB R O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKS Aworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 49 Figure 13: Mean number of Zonocerus variegatus recorded from October - December. In the dry season, the number of insects recorded was observed to be fluctuating from the 1st week to until 6th week. The Round garden egg had the highest number of Zonocerus variegatus with mean number of 4.00 and peak recorded in the 4th week. The Legon 1 and Aworoworo varieties recorded the least number of Zonocerus variegatus with average numbers of 1.5 respectively. The Fig 14 below shows the population trend of Zonocerus variegatus in the dry season. 0 0.2 0.4 0.6 0.8 1 1.2 1.4 0 1 2 3 4 5 6 7 8 M EA N N U M B ER O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKSAworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 50 Figure 14: Mean number of Zonocerus variegatus recorded from February - April. In the major season, generally, the Round garden egg variety recorded the highest number of Zonocerus variegatus with average number of (3.3). The number of Zonocerus variegatus found to be increasing from the 2nd and reached its peak during the 4th week from where the number of Zonocerus variegatus began to reduce. In general, the Legon 1 variety recorded the least number of insects with mean value of 0.8. 0 0.2 0.4 0.6 0.8 1 1.2 1.4 0 1 2 3 4 5 6 7 M EA N N U M B ER O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKSAworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 51 Figure 15: Mean number of Zonocerus variegatus recorded from June – July. 4.1.6 Leucinodes orbonalis. Leucinodes orbonalis was found in the major season i.e. October -December. Consequently, the number of Leucinodes orbonalis was found to be fluctuating from the first week to the time of sixth week. The Legon 1 variety recorded the highest number of Leucinodes orbonalis with an overall number of (24.2) highest whilst the Yorgbe variety recorded the least number of Leucinodes orbonalis with mean number of (3.9). The highest peak was recorded by the Legon 1 variety in the 5th week. The Figure 16 below shows the population trend of the Leucinodes orbonalis in the minor season. 0 0.2 0.4 0.6 0.8 1 1.2 0 1 2 3 4 5 6 7 8 M EA N N U M B ER O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKSAworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 52 Figure 16: Mean number of Leucinodes orbonalis recorded from October – December. In the dry season, the Round garden egg variety recorded the highest number of Leucinodes orbonalis with average number of (0.6) whilst the Legon 1 variety recorded the least with mean number of 0.3. Two peaks were observed in the 5tt and 6th weeks by the Round garden egg and Legon 1 varieties found to be increasing from the 2nd and reached its peak during the 4th week from where the number of Leucinodes orbonalis began to reduce. In general, the Legon 1 variety recorded the least number of insects with mean value of 0.8. 0 2 4 6 8 10 12 14 0 1 2 3 4 5 6 7 M EA N N U M B ER O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKSAworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 53 Figure 17: Mean number of Leucinodes orbonalis borer recorded from February – April. In the major season, the Aworoworo and Yorgbe varieties recorded the highest number of Leucinodes orbonalis with average number of (5.3) respectively whilst the Legon 1 variety recorded the least with mean number of 0.6. The highest peak was recorded by the Yorgbe variety in the 6th week. 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0 1 2 3 4 5 6 7 M EA N N U M B ER O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKSAworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 54 Figure 18: Mean number of Leucinodes orbonalis recorded from June – July. Survey of the major pests that attack the different growing stages of garden eggs. Aphis gossypii Table 4 - 6 shows the various insects that attack the different growing stages of the varieties. In the minor raining season, the Yorgbe variety recorded the highest number of Aphis gossypii attacking the different varieties (165.2±31.5) whilst the Aworoworo variety recorded the least number (114.8±14.9) at the vegetative stage in the minor season. At the flowering and fruiting stages, the Legon 1 variety was found to be the variety with the highest numbers of (119.00 ± 13.5) and (487.83 ± 56.7) respectively. However, the Yorgbe variety (14.7) and the round garden egg (84.2) varieties recorded the least number of Aphis gossypii at the flowering and fruiting stages. There were no significant differences in the number of Aphis gossypii that attacked the different growing stages. 0 1 2 3 4 5 6 0 1 2 3 4 5 6 7 M EA N N U M B ER O F IN SE C TS /T R EA TM EN T/ P LA N T WEEKSAworoworo Yorgbe Round garden egg Legon 1 University of Ghana http://ugspace.ug.edu.gh 55 Aphis craccivora At the vegetative stage, the Legon 1variety recorded the highest number of Aphis craccivora (450.0±23.9) whilst the Yorgbe variety recorded the least number (0.00 ± 0.00). Again, the Legon 1 variety also recorded the highest number at both the flowering stage (460 ± 12.42) whist the round garden egg variety recorded the highest at fruiting stage (435.66 ± 10.29). Yorgbe variety recorded the least number at flowering stage (0.00 ± 0.00) whilst the Legon 1 variety had the least number of black bean aphid (41.3 ± 3.7). There were significant differences in the number of Aphis craccivora that attacked the different growing stages at (P < 0.05). Thrips tabaci For Thrips tabaci, the Legon 1 variety recorded the least number at both the vegetative and flowering stages however, towards the fruiting stage, the number of thrips increased (8.3 ± 0.3). The Aworoworo variety recorded the highest number at the vegetative stage (1.3± 0.1) and flowering stage (4.0) whilst Yorgbe variety recorded the least number of thrips at the fruiting stage (4.0 ± 0.9). There were no significant differences in the number of thrips that attack the different growing stages of the varieties in the minor season. Zonocerus variegatus In the minor season, Zonocerus variegatus was found to attack the different stages of the garden egg. At the vegetative stage, the Yorgbe and Legon 1 varieties recorded the highest respectively whilst the Aworoworo and Round garden egg varieties recorded the least. There were no significant differences in the number of insects that attacked the different stages at the vegetative stage. The Legon 1 variety recorded the highest number of insects at both the flowering (2.0 ± 0.0) and fruiting stages (0.7 ± 0.1) respectively. However, the Aworoworo and Round garden egg University of Ghana http://ugspace.ug.edu.gh 56 varieties recorded the least at the flowering stage with mean number of (0.2 ± 0.04) whereas the Yorgbe and Aworoworo varieties recorded the least at the fruiting stage. There were significant differences in the number of Zonocerus variegatus that attacked the different varieties at the flowering stage at (P < 0.05) but at the fruiting stage there were no significant differences. Leucinodes orbonalis At the vegetative stage, Leucinodes orbonalis was not recorded however, their numbers began to increase toward the flowering and fruiting stages. At the flowering stage, the Aworoworo variety recorded the highest (3.5 ± 0.4) whilst the Legon 1 variety recorded the least (1.5 ± 0.2). At the fruiting stage, the number of insects that attacked the Legon 1 variety increased with a mean value of (22.7 ± 1.1) whilst the Aworoworo variety recorded the least (1.8 ± 0.2). There were no significant differences in the number of Leucinodes orbonalis that attacked the different varieties at the flowering stage however, significant difference was observed in the fruiting stage at (P > 0.05). Table 4 - 6 shows the number of insects that attacked the different growing stages in the minor season. University of Ghana http://ugspace.ug.edu.gh 57 Table 4: Insects that attack the garden eggs at the vegetative stage in the minor season Treatment Aphis gossypii Aphis craccivora Thrips tabaci Urentius hystricellus Zonocerus variegatus Leucinodes orbonalis Aworowor o 114.8 ± 14.9a 120.0 ± 7.4b 1.3 ± 0.1b 0 ± 0.0 0.3 ± 0.1a 0 ± 0.0a Yorgbe 165.1 ± 31.5a 0.0 ± 0.0a 0.3 ± 0.1a 0 ± 0.0 0.7 ± 0.1a 0 ± 0.0a Round garden egg 142.0 ± 16.5a 20.0 ± 0.41a 0.7 ± 0.1ab 0 ± 0.0 0.3 ± 01a 0 ± 0.0a Legon 1 147.5 ± 25.0a 450.0 ±23.9c 0 ± 0.0a 0 ± 0.0 0.7 ± 0.1a 0 ± 0.0a Fpr 0.90 0.001 0.037 0.00 0.30 0.00 Table 5: Insects that attack the garden eggs at the flowering stage in the minor season Treatment Aphis gossypii Aphis craccivora Thrips tabaci Urentius hystricellus Zonocerus variegatus Leucinodes orbonalis Aworowor o 82.3 ± 12.2ab 138.0 ± 6.01c 4.0± 0.9a 0.0 ± 0.0a 0.2 ± 0.04a 3.5 ± 0.4a Yorgbe 14.7 ± 2.6a 0.0 ± 0.0a 3.3 ± 0.5a 0.0 ± 0.0a 0.3 ± 0.1a 1.7 ± 0.2a Round garden egg 60.2 ± 8.3ab 26.7 ± 4.1b 2.0 ± 0.3a 0.0 ± 0.0a 0.2 ± 0.04a 2.2 ± 0.3a Legon 1 119 ± 13.5b 460.0 ± 12.4d 0.0 ± 0.0a 0.0 ± 0.0a 2 ± 0.0b 1.5 ± 0.2a Fpr 0.20 0.001 0.44 0.00 0.004 0.69 University of Ghana http://ugspace.ug.edu.gh 58 Table 6: Insects that attack the garden eggs at the fruiting stage in the minor season Treatment Aphis gossypii Aphis craccivora Thrips tabaci Urentius hystricell us Zonocerus variegatus Leucinodes orbonalis Aworowor o 151.5 ± 18.9ab 187.8 ± 6.7b 8 ± 1.1a 0 ± 0.0 0.3 ± 0.1a 1.8 ± 0.2a Yorgbe 236.8 ± 32.2ab 41.3 ± 3.7a 3 ± 0.5a 0 ± 0.0 0.3 ± 0.1a 2.2 ± 0.2a Round garden egg 84.2 ± 6.0a 435.7 ± 10.3c 5.5 ± 0.5a 0 ± 0.0 0.5 ± 0.04a 2.3 ± 0.3a Legon 1 460.0 ± 12.4d 0 ± 0.0a 0 ± 0.0a 2 ± 0.0b 119.0 ± 13.5b 22.7 ± 1.1a Fpr 0.13 0.001 0.43 0.00 0.94 0.001 Aphis gossypii Table 7 - 9 shows the various insects that attacked the different growing stages of the varieties. In the dry season, the Yorgbe variety recorded highest mean numbers both at the vegetative stage (222.2 ± 15.04) and flowering stage (257.5 ± 25.8), however, their numbers reduced at fruiting stage (55.8 ± 5.5). Although there was a decline in the mean number of Aphis gossypii at fruiting stage for Yorgbe variety, the variety that recorded the least number of insects at the fruiting stage is the Aworoworo variety (28.3 ± 5.5). At the vegetative stage, the Legon 1 variety recorded the least number of Aphis gossypii (145.8 ± 12.4) whilst at the flowering stage, the Round garden egg variety recorded the least number of Aphis gossypii (124.2 ± 7.9). There were no significant differences in the number of Aphis gossypii that attacked the different growing stages of the varieties. University of Ghana http://ugspace.ug.edu.gh 59 Aphis craccivora The mean number of Aphis craccivora increased from the vegetative stage through to the fruiting stage. As a result, it was the Legon 1 variety that recorded the highest number at both the vegetative stage (14.3 ± 3.5) and fruiting stage (243.0 ± 35.3). Also the Aworoworo variety recorded the least number at the vegetative stage (0.00 ± 0.00) and flowering stage (25.8 ± 1.4) whilst the Yorgbe variety recorded the highest mean number at the flowering stage (134.2 ± 8.7). There were no significant differences in the number of Aphis craccivora that attacked both the vegetative and flowering stages however there were significant differences in the number that attacked the varieties in the fruiting stage. Thrips tabaci In the dry season, the Yorgbe variety recorded the highest number of Thrips tabaci (1.5 ± 0.2) whilst the Aworoworo variety (0.7 ± 0.1) recorded the least at the vegetative stage. During the flowering stage, the Legon 1 variety recorded the highest number (3.5 ± 0.4) whilst the Yorgbe variety recorded the least (1.5 ± 0.2) whilst at the fruiting stage, the round garden egg variety recorded the highest number (5.0 ± 0.6) whilst the Yorgbe variety recorded the least (1.3 ± 0.1a). Throughout the different growing stages of the garden eggs, there were no significant differences in the number of Thrips tabaci that attacked the different stages of the varieties. Urentius hystricellus The highest number of Urentius hystricellus was found in the dry season. As a result, high numbers of eggplant lacebug was recorded for the different varieties. The variety that recorded the highest number of Urentius hystricellus at the vegetative stage was the round garden egg variety (76.2 ± University of Ghana http://ugspace.ug.edu.gh 60 11.1) whilst the Legon 1 variety recorded the least (36.7 ± 3.5). At the flowering stage, the Yorgbe variety recorded the highest number (535.0) whilst the Aworoworo variety recorded the least number (90.4). At the fruiting stage, the Round garden egg variety was to be the variety that recorded the highest number (568.3) whereas the Legon 1 variety recorded the least (206.7). There were no significant differences in the number of Urentius hystricellus that attacked the different varieties. Zonocerus variegatus. In the dry season, the Zonocerus variegatus was found to attack the different stages of the garden egg. At the vegetative stage, the Legon 1 varieties recorded the highest (0.5 ± 0.8) whilst the Aworoworo and Yorgbe varieties recorded the least (0.0 ± 0.0). There were no significant differences in the number that attacked the different stages at the vegetative stage. The number of variegated grasshopper that attacked the Yorgbe variety at the flowering stage (1.5 ± 0.2) at the flowering stage. However, the Round garden egg variety recorded the least at the flowering stage with mean number of (0.2 ± 0.2) but at the fruiting stage, their numbers increased Yorgbe and Aworoworo varieties recorded the least at the fruiting stage. There were no significant differences in the number that attacked the different varieties at the flowering and fruiting stage. Leucinodes orbonalis At the vegetative stage, Leucinodes orbonalis was not recorded however, their numbers began to increase toward the flowering and fruiting stages. At the flowering stage, the Round garden egg variety recorded the highest (0.3 ± 0.1) whilst the Legon 1 variety recorded the least (0.0 ± 0.0). At the fruiting stage, the number of insects that attacked the Legon 1 increased with a mean value of (0.3 ± 0.1) whilst the number of insects that attacked the Round garden egg increased (0.3 ± University of Ghana http://ugspace.ug.edu.gh 61 0.1). The Aworoworo and the Yorgbe varieties recorded the least number of Leucinodes orbonalis. There were no significant differences in the number that attack the different varieties at the flowering and fruiting stages respectively. Table 7: Insects that attack the garden eggs at the vegetative stage in the dry season Treatment Aphis gossypii Aphis craccivora Thrips tabaci Urentius hystricellus Zonocerus variegatus Leucinodes orbonalis Aworowor o 164.8 ± 15.3a 0 ± 0.0a 0.7 ± 0.11a 56.2 ± 12.61a 0.2 ± 0.04a 0 ± 0.0a Yorgbe 222.2 ± 15.04a 5.5 ± 0.98a 1.5 ± 0.20a 46.8 ± 7.20a 0 ± 0.0a 0 ± 0.0a Round garden egg 190 ± 20.84a 9.2 ± 2.29a 0.8 ± 0.14a 76.2 ± 11.05a 0 ± 0.0a 0 ± 0.0a Legon 1 145.8 ± 12.38a 14.3 ± 3.53a 1.2 ± 0.13a 36.7 ± 3.51a 0.5 ± 0.8a 0 ± 0.0a Fpr 0.89 0.55 0.85 0.87 0.20 0.00 Table 8: Insects that attack the garden eggs at the flowering stage in the dry season Treatment Aphis gossypii Aphis craccivora Thrips tabaci Urentius hystricellus Zonocerus variegatus Leucinodes orbonalis Aworowor o 184.2 ± 15.3a 25.8 ± 1.4a 1.7 ± 0.2a 93.3 ± 18.2a 0.5 ± 0.1a 0.2 ± 0.4a Yorgbe 257.5 ± 25.8a 134.2 ± 8.7a 1.5 ± 0.2a 224.8 ± 28.1a 1.5 ± 0.2a 0.2 ± 0.4a Round garden egg 124.2 ± 7.9a 97.5 ± 17.5a 2.7 ± 0.3a 158.2 ± 22.4a 0.2 ± 0.2a 0.3 ± 0.1a Legon 1 169.2 ± 23.2a 80 ± 12.7a 3.5 ± 0.4a 131.8 ± 13.2a 0.5 ± 0.1a 0 ± 0.0a Fpr 0.87 0.35 0.74 0.97 0.55 0.76 University of Ghana http://ugspace.ug.edu.gh 62 Table 9: Insects that attack the garden eggs at the fruiting stage in the dry season Treatment Aphis gossypii Aphis craccivora Thrips tabaci Urentius hystricellus Zonocerus variegatus Leucinodes orbonalis Aworowor o 28.3±5.5a 3.3 ± 0.5a 1.7 ± 0.3a 268.3±23.3a 0.8 ± 0.01a 0.17±0.4a Yorgbe 55.8 ± 5.5ab 8.3 ± 1.3a 1.3 ± 0.2a 328.3 ±44.3a 0.67 ± 0.1a 0.17 ± 0.4a Round garden egg 50.0 ± 3.2ab 38.3 ± 8.0a 5.0 ± 0.6a 373.8±52.4a 2.3 ± 0.2a 0.33 ± 0.1a Legon 1 185.0 ± 23.2b 243 ± 35.3b 3.2 ± 0.5a 330.0±41.3a 0.5 ± 0.1a 0.3 ± 0.1a Fpr 0.13 0.05 0.71 0.72 0.36 0.89 Aphis gossypii The Aphis gossypii was found to attack the developmental stages of the different garden egg varieties in the major season as shown in Table 10. The Legon variety recorded the highest at the vegetative stage (65.8 ± 5.9) whilst the Yorgbe variety recorded the least number (30.8 ± 2.1bc). Although the Legon 1 variety recorded the highest mean number at fruiting stage (113.3), the mean number recorded at the flowering stage reduced (22.5). At the flowering stage, the Yorgbe variety recorded the least number (10.0) whilst the Aworoworo variety recorded the highest (36.7). Finally, at the fruiting stage, the Yorgbe variety recorded the least number of Aphis gossypii (50.0). There were no significant differences in the number that attacked the different varieties. University of Ghana http://ugspace.ug.edu.gh 63 Aphis craccivora At the vegetative as shown in Table 10 – 12, the Round garden egg variety recorded the highest number of Aphis craccivora (87.5) whilst the Legon 1 variety recorded the least number (7.0). Again, the Round garden egg variety also recorded the highest number at both the flowering stage (53.3) whist the Legon 1 variety recorded the least at flowering stage (8.3). It was also found that the round garden egg variety recorded the highest number at fruiting stage (93.3) whilst the Aworoworo variety had the least number of Aphis craccivora (15.8) at the fruiting stage. At the vegetative stage, there were significant (P < 0.05) differences in the number of Aphis craccivora that attacked the different varieties at however, no significant differences was observed at both the flowering and fruiting stages. Thrips tabaci In the major season, not very high numbers were recorded for the different varieties however, the Legon 1 variety and the Round garden egg variety recorded the highest numbers (5.00) whilst Aworoworo variety recorded the least number of thrips (3.83) at the vegetative stage. During the flowering stage, the Legon 1 variety recorded the least number (2.00) whilst the Aworoworo variety recorded the highest (3.67) whilst at the fruiting stage, the round garden egg variety recorded the highest number (5.33) and the Yorgbe variety recorded the least (4.50). There were no significant differences in the number of thrips that attacked the different varieties in the different seasons. Urentius hystricellus In table 10 - 12, the number of Urentius hystricellus recorded in the major season was not as high as the one recorded in the dry season. As a result, the Aworoworo variety recorded the highest University of Ghana http://ugspace.ug.edu.gh 64 number of Urentius hystricellus (6.17) whilst the Round garden egg variety recorded the least (2.00) at the vegetative stage. At the flowering stage, the Legon 1 variety recorded the highest number (2.83) whilst the Round garden egg variety recorded the least number (1.33). At the fruiting stage, the Round garden egg variety was to be the variety that recorded the least number (0.00) whereas the other three varieties recorded the same numbers (0.33). There were no significant differences in the number that attacked the different varieties in the different seasons. Zonocerus variegatus. In the major raining season, the Zonocerus variegatus was found to attack the different stages of the garden egg. At the vegetative stage, the Legon 1 and Yorgbe varieties recorded the highest with mean values of (0.7 ± 0.07) respectively whilst the Aworoworo variety recorded the least (0.2 ± 0.04). There were no significant differences in the number of Zonocerus variegatus that attacked the different stages at the vegetative stage. The Round garden egg variety recorded the highest at the flowering stage (1.0 ± 0.2). At the fruiting stage, the number that attacked the different varieties increased. The Round garden egg variety recorded the highest at the fruiting stage with mean number of (2.0 ± 0.2) with the Legon 1 variety recording the least (0.3 ± 0.1). There were no significant differences in the number of variegated grasshoper that attacked the different varieties in the different seasons. Leucinodes orbonalis At the vegetative stage, the Round garden egg variety recorded the highest number (0.5 ± 0.04). Numbers began to increase at the flowering stage with Legon 1 variety recorded the highest (1.5 University of Ghana http://ugspace.ug.edu.gh 65 ± 0.2) whilst the Yorgbe variety recorded the least (0.3 ± 0.1). At the fruiting stage, same number of Leucinodes orbonalis attacked the Aworoworo and Yorgbe varieties with mean values of (5.3 ± 0.4) and (5.3 ± 0.3) respectively whilst the Round garden egg and Legon 1 varieties recorded the least number of Leucinodes orbonalis (2.7 ± 0.3a) and (2.7 ± 0.2a) respectively. There were no significant differences in the number of Leucinodes orbonalis that attack the different varieties at the vegetative stage, flowering and fruiting stage respectively. Table 10: Insects that attack the garden eggs at the vegetative stage in the major season Treatment Aphis gossypii Aphis craccivora Thrips tabaci Urentius hystricellus Zonocerus variegatus Leucinodes orbonalis Aworowor o 33.3 ± 2.9ab 19.5±3.4a 1.2 ± 0.1a 1.2 ± 0.13a 0.2 ± 0.4a 0 ± 0.0a Yorgbe 30.8 ± 2.1bc 47.5±4.2a 2.2 ± 0.04a 2.2 ± 0.04a 0.7 ± 0.1a 0 ± 0.0a Round garden egg 48.3 ± 5.4c 87.5±9.9a 2.7 ± 0.23a 2.7 ± 0.23a 0.3 ± 0.1a 0 ± 0.0a Legon 1 65.8 ± 5.9a 7 ± 1.14a 4.7 ± 0.49a 4.7 ± 0.49a 0.7 ± 0.1a 0 ± 0.0a Fpr 0.60 0.02 0.30 0.22 0.40 0.03 University of Ghana http://ugspace.ug.edu.gh 66 Table 11: Insects that attack the garden eggs at the flowering stage in the major season Treatment Aphis gossypii Aphis craccivora Thrips tabaci Urentius hystricellus Zonocerus variegatus Leucinodes orbonalis Aworowor o 36.7 ± 5.9a 16.7 ± 2.5a 6.3 ± 0.4a 1.8 ± 0.4a 0 ± 0.0a 0.7 ± 0.1a Yorgbe 10 ± 1.3a 36.7 ± 7.8a 5 ± 0.4a 1.7 ± 0.4a 0 ± 0.0a 0.3 ± 0.1a Round garden egg 23.5 ± 1.92a 53.3 ± 6.85a 5.0 ± 0.05a 1.33 ± 0.24a 1.0 ± 0.2b 0.5 ± 0.1a Legon 1 22.5 ± 3.03a 8.3 ± 2.08a 2.3 ± 0.14a 2.83 ± 0.5a 0.0 ± 0.0a 1.5 ± 0.2a 0.75 0.34 0.14 0.88 0.10 0.55 Table 12: Insects that attack the of garden eggs at the fruiting stage in the major season Treatment Aphis gossypii Aphis craccivora Thrips tabaci Urentius hystricellus Zonocerus variegatus Leucinodes orbonalis Aworowor o 84.2 ± 4.1a 15.8 ± 1.7a 5.8 ± 0.2b 0.3 ± 0.1a 1.2 ± 0.2a