HORTINLEA - Influence of cultural practices (Fertilizer Application) on insect pest incidence mediated by secondary plant metabolites

Indigenous Leafy Vegetables (i.e. Amaranth (Amaranthus spp.), African Nightshade (Solanum scabrum), Spiderplant (Cleome spp.), Ethiopian kale (B. carinata) and Rattlepod (Crotolaria spp.) are important sources of food and nutritional security (Yang and Keding, 2009) as well as income for many rural and urban households in Africa. This has led to promotion of their production and consumption. For instance between 2001 and 2006, there was an increase in consumption by 213% in Kenya (Irungu, 2007). Despite the increase, the yield and quality of these leafy vegetables is constrained by several pests (Sithanantham et al., 2003). of which application of synthetic pesticides has remained the standard management method. Moreover pest problems are sometimes amplified by unbalanced use of fertilizer (Pasquini et al. 2009). In many crops farmers routinely spray pesticides twice a week throughout the production cycle (Akemn et al. 1999, Agbicodo 2011) and foster well known toxicological and environmental problems of the disastrous spiral in synthetic pesticide use. There is therefore the need to identify, test and promote more sustainable pest and disease management for production of healthy indigenous vegetables.