Assessing the effects of agroforestry practices on biological control potential in kale (Brassica oleracea acephala) plantations in Western Kenya

摘要: Agricultural intensification and extension at the expense of forests are known to have a negative impact on biodiversity ecosystem services. In Sub-Saharan Africa (SSA), agriculture provides livelihoods for most population forestry is an important additional income. Agroforestry practices may help compensate loss biodiversity. Pests constraint agricultural production their biological control affected by environmental degradation. Management such as alteration field micro-environment increases in landscape complexity can be efficient non-chemical methods reducing pest damage. this study, I examine how implementation agroforestry influences kale (Brassica oleracea var. acephala) plantations Western Kenya. Twenty fields, either shaded or open, were selected four settlements Trans-Nzoia district Kenya. Landscape was defined percentage wooded vegetation within 50 m radius. Pesticide use, mulching amount rainfall recorded explanatory variables. Predation assessed (1) egg removal rates, (2) bird exclusion, (3) predation marks plasticine caterpillars. Activity density ground-dwelling predators with pitfall traps foliage-dwelling pests counted plants. Aphid parasitism rates also estimated counting live aphids aphid mummies. The effect shade complexity, pesticide tested running generalized linear models selecting best based Akaike Information Criterion adjusted small sample-sizes. Presence shade-trees local level found effective both surveyed increasing caterpillar birds. Neither proportion nor interaction between scale tree cover retained significant However, pesticides negatively influenced abundances, predator abundances while positively influencing populations. I conclude that agro-forestry systems Kenya, management pests, but no evidence trees important. This explained small-scale analysis should investigated larger stronger differences versus conventional systems. note further order improve sustainability farming practices.