Browsing by Author "Yawson, G.K."
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Item The Effect of some oil palm Elaeis guineensis Jacq. Progenies on development of the oil palm Leaf miner, Coelaenomenodera lameensis Berti and Mariau (Coleoptera: Chrysomelidae) in Ghana.(African Journal of Science and Technology 2(8): 92-96., 2007) Appiah, S.O.; Dimkpa, S.O.N.; Yawson, G.K.The oil palm leaf miner, C lameensis is currently the most destructive pest of oil palm in Ghana and other oil palm growing countries in Africa and causes considerable losses in the yield of fresh fruit bunches. Experiments conducted at the Oil Palm Research Institute in Ghana revealed no significant differences (P>0.05) in the duration of the various developmental stages of C. lameensis on five oil palm progenies coded A, B, C, D and E. However, slight variations in the ability of the progenies, to support the development and growth of the oil palm leaf miner were observed. The longest developmental period was on progeny D (100.8 days) and the shortest were on progenies C and E (98.2days). The mean duration of the various development stages were, 18.5 days egg incubation, 46.1 days for larval development, 13.6 days from pupal to external adult and 20.6 days from external adult emergence to egg laying with a total life cycle of 99 days.Item Relative abundance of insect species in oil palm - cocoa intercrop at Kusi in the Eastern Region of Ghana(INTERNATIONAL RESEARCH JOURNALS, 2011) Bawa, A.S.; Yawson, G.K.; Ofori, S.E.; Appiah, S.O.; Afreh-Nuamah, K.Insect species of sole oil palm, sole cocoa and oil palm cocoa intercrop was studied at the CSIR-Oil Palm Research Institute; on plot K4 while cocoa monocrop at a farm on the boundary of the Institute’s plantation at Kusi, in the Eastern Region of Ghana. The objective was to identify the occurrence and relative abundance of these insect species in oil palm-cocoa intercrop to compare these insects with existed ones in oil palm and cocoa monocrops over a period of six months (September 2008 to February 2009). Chemical knockdown application method by fumigation was employed to collect insect. An area 0.5 ha plot each was demarcated for the treatments; i.e oil palm monocrop, cocoa monocrop and oil palm-cocoa intercrop. The oil palm and cocoa plantations were 29 years and 21 years respectively. Vinyl sheets measuring 2.8 X 8 m each were placed beneath the selected trees for the insect collection, and the trees were hot-fogged early in the morning between 5:00–7:30am with Plan D EC25 insecticide (Deltamethrin 25g active ingredient/L) at a rate of 20ml insecticide/ 4.5 l of diesel using a Puls FOG machine (K-10SP). Results showed that relatively more insects occurred in the oil palm-cocoa intercrop compared to the oil palm and cocoa monocrops. Insect species belonging to six orders were collected as follows; Hymenoptera (12), Coleoptera (30), Diptera (10), Hemiptera (6), Thysanoptera (1) and Orthoptera (1). Oecophylla longinoda Latr. was the dominant insect species in studied plots. There were more beneficial insect species (predators and parasitoids) in the intercrop when compare to the monocrops. There were significant differences (p < 0.001) in the number of insect species between cocoa monocrop and oil palm monocrop, similarly oil palm monocrop and oil palm-cocoa intercrop. However there was no significant difference (p > 0.001) species between cocoa monocrop and oil palm-cocoa intercrop. The study revealed that the two crops do not have common insect pests and in association will not compound insect pests problem of either crop.Item The susceptibilitity of some oil palm Elaes guineensis Jack, Progenies to Coelaenomenodera Berti & Mariau, (Coleoptera: Chrysomelidae)(Current Research Journal Journal of Biological Science, 2009) Afreh-Nuamah, K.; Dimpka, S.O.N.; Appiah, S.O.; Yawson, G.K.Damage by the oil palm leaf miner C. lameensis has been observed in all oil palm growing countries in Africa causing wide spread defoliation and result to considerable reduction in the yield of fresh fruit bunches (ffb). The understanding of the susceptibility levels of different oil palm progenies to the oil palm leaf miner C. lameensis become highly imperative in the development and incorporation of host plant resistance in the integrated pest management strategy for the management of the oil palm leaf miner. By means of no-choice destructive sampling field experiments, differences in the population levels of the various stages of development and the assessment of damage caused by larval feeding were studied. All the five progenies were averagely susceptible to damage caused by the larvae of C. lameensis. No significant differences (P>05) were observed in the assessed parameters such as percentage egg laid, adult survival in cages, egg hatching, larval and pupal survival on the progenies. However, progeny D supported the least mean population (45.9%) of the larva, pupa and adults of C. lameensis with consequent slight damage of 25%. Progenies C, B and A followed in that order. Progeny E supported the highest mean population of the insect (54%) and suffered the highest damage of 37.4%. The slight variation observed suggests potential differences in the genetic make up of the palm. This can create an opportunity for incorporating host plant resistance for the development of an integrated management strategy for the oil palm leaf miner.