EVALUATING THE IMPACTS OF CROTOLARIA JUNCEA, SUNN HEMP, ON ARTHROPOD POPULATIONS AND PLANT GROWTH AND DEVELOPMENT IN A ZUCCHINI INTER-CROPPED AGROECOSYSTEM

Abstract

Recently, studies have shown that crop diversification strategies can be effective and sustainable means of suppressing pests, improving crop growth and enhancing beneficial soil organisms. Experiments were conducted in 2009, 2010 and 2011 to investigate the impacts of the tropical cover crop sunn hemp (SH), Crotalaria juncea, utilized as a living mulch and green manure on insect populations, crop growth and the nematode community. When inter-planted as a living mulch, SH reduced populations of cucumber beetles (Acalymma spp. and Diabrotica spp.) compared to monoculture zucchini, Cucurbita pepo, plots. When SH was utilized as an organic mulch, SH treatment plots resulted in significantly larger zucchini plant biomass and yield than monoculture plots. In 2011 when SH was strip-tilled, this resulted in a more nutrient enriched soil as indicated by nematode abundances and calculated soil health indices compared to monoculture plots. Organic fertilizer application resulted in late-season increases in bacteria feeding nematodes