On Farm And Post-Harvest Management Of Mango Stone Weevil (Sternochetus mangiferae F.)

Abstract

A questionnaire composed of twenty-three (23) open and closed-ended questions was administered to thirty (30) mango farmers within the eastern mango enclave to investigate the level of mango stone weevil (MSW) infestation within the eastern mango enclave. Data obtained from the questionnaire was analysed using the SPSS version 25.0 and presented as tables in percentages. Chi-square was used to determine the association between selected parameters. The response from farmers revealed that 40.7% of farmers grow only one variety of mango and the common variety is Keitt which is cultivated by 33.7% of the farmers. About eighty-seven percent of the farmers admitted to the presence of the mango stone weevil on their farms. Fifty percent of the farmers were found to be relying on insecticides for controlling the MSW. About seventy-seven percent of the respondents viewed the mango stone weevil as a major pest because it is a pest of phytosanitary importance. The major mango season was considered to have the highest infestation as indicated by 90% of respondents. Responses from farmers revealed that 76.7% spend about GH¢2000:00 – 5000:00 per acre every season in controlling the mango stone weevil. A survey was conducted during the major and minor mango seasons immediately after the questionnaire administration. During the survey, thirty (30) farms were visited. On each farm, fifty (50) matured fruits were randomly picked and dissected to check whether the seeds are infested or free from weevils. The survey brought to light that, the MSW is at its highest level during the major season as compared to the minor season. Infestation levels on the average were 23.6% and 19.13% for the major and minor seasons respectively. To determine the effect of trunk banding using a sticky band, grease and insecticide in the control of MSW, the sticky band proved to be the most efficient method. The sticky band had lower fruit infestation levels (i.e., 11.5% for minor mango season and 10.5% for the major mango season) which were significantly different from the fruit infestation levels of the grease banding for both minor and major seasons. Although an X-ray imaging technique could not capture the image of mango stone weevil within infested fruits, it was able to capture the image of damaged cotyledon which resulted from feeding by mango stone weevils. The findings of the research showed that the mango stone weevil is persistent in the study area, mango stone weevil infestation levels are high during the major mango season, the sticky band is more effective in controlling the mango stone weevil and lastly soft X-ray technique can be used to detect internal infestation of mango by the stone weevil. These findings would go a long way to address the menace of MSW infestation, the efficient and effective method of controlling mango stone weevil and a non-destructive method of detecting MSW infestations which would improve the fortunes of Ghana in the export of fresh mango fruits.