| dc.description.abstract | African leafy vegetables (ALVs) have a potential of contribution to food security by providing
essential micronutrients especially among marginalized rural communities. ALVs, thought to be
more tolerant to biotic and abiotic stresses, have received little scientific inquiry on insect pest
dynamics, which would lead to low yields and poor quality under different agro-ecological zones
(AEZs). Insect pests affecting crops usually vary with The overall objective of this study was to
identify and determine the prevalence and nature of damage of insect pests on Cleome gynandra,
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one of the most popular ALVs. The studies were conducted in Lugari and Keiyo districts of
Kenya falling under Upper Midland (Transitional) and Humid AEZs, respectively, during the
long rains and short rains of 2002. The crop was planted following farmers’ agronomic practices
on plots measuring 18 x 2m and replicated four times. The plants grown in the drier Lugari and
wetter Keiyo District were attacked by 8 and 7 insect species, respectively. Diamondback moth
(Plutella xylostella), African bollworm (Helicoverpa armigera), black bean aphids (Aphis
fabae), cotton aphids (Aphis gossypi) and Systates weevil (Systates pollinosus) attacked the crop
in both AEZs. Leaf roller (Sylepta derogate), cabbage sawfly (Athelia spp) and chafer grub
(Schizonycha spp) were detected at Lugari while cutworms (Agrotis spp), flea beetles
(Chrysomelidae spp),) and cucurbit ladybird beetle (Epilachna spp) were found attacking the
crop only in Keiyo district. Diamondback moth and aphids were more prevalent and caused more
damage in Lugari, especially during the short rains. Helicoverpa was slightly more prevalent in
Keiyo for a short period between 6-8 weeks after planting. There was no difference in prevalence
and severity of systates between the 2 AEZs. The study results indicate that insect pests caused
significant damage to Cleome gynandra and the presence and severity of damage varied with
AEZ and season. | |
