Effects cascaded to the yield with all botanical treatments giving cabbage yield per unit area, andmost giving head weights, comparable to Attack®. The cost of eachtreatment including material and labour in the field experiments as well asthe revenue derived from both the marketable (undamaged) and damaged yield of cabbage was calculated. The cost: benefit ratios of sprayed treatments were derived by comparing the cost of each plant protection regime against the additional market value of the treatment yield above that obtained in an unsprayed control treatment. With the exception of plotssprayed with an extract of N. tabacum, the cost of plant protection using Attack® was higher than any of the botanicals in both seasons. In the major rainy season, the highest cost: benefit ratio of 1: 29 was observed for plots sprayed with an extract of C. odorata and was followed closely by N.tabacum treatment with 1: 25 with Attack® recording 1: 18. In the minorseason, plots sprayed with Attack® had the highest cost: benefit ratio of 1:15 and was followed closely by N. tabacum with 1: 14. Botanical insecticides differed markedly in cost: benefit and some were comparable to that from conventional insecticide. Overall, this thesis showed that simply-prepared extracts from readily available Ghanaian plants offer cost-effective means of managing pests ofcabbage and are safe to beneficial arthropods. These botanicals merit further research as a cheap plant protection strategy for smallholding farmers in West Africa.
|Qualification||Master of Philosophy|
|Award date||01 Aug 2013|
|Place of Publication||Australia|
|Publication status||Published - 2014|