<i>Piper</i> <i>guineensis</i> Extract in Maize-soybean, Maize-okra Intercropping Systems: Its Role in Mitigating Maize (<i>Zea mays</i>) Pests and Boosting Soil Fertility

Abstract

Maize (Zea mays) is an important staple grown worldwide including Cameroon, for its carbohydrate rich grains in addition to minerals and vitamins, therefore providing food for human consumption, and fodder for livestock. Production in Cameroon especially Buea which is the main hub is constraint by several factors among them, pests including the Fall Army Worm (FAW), Snail (<i>Limicolaria</i> sp.) and soil infertility are of high importance. The use of botanicals has been successful in mitigating pests on crops while intercropping economic crops with legumes increases soil fertility. This study therefore aimed at evaluating the efficacy of extract of <i>Piper guineense</i> on maize-okra, and maize-soybean intercropped on the incidence and severity of these pests and soil primary macronutrients. The experiment was a randomized complete block design with six treatments replicated three times at the Faculty of Agriculture and Veterinary Medicine, University of Buea. FAW, snail incidence and severity, maize grain weight, and soil primary macronutrients were recorded. Data collected was subjected to statistical analysis (<I>P</I>< 0.05). FAW and snail incidence and severity differed significantly (<I>P</I><0.05). FAW incidence was highest in the control (69.2%) and lowest in Maize + soybean + <i>Piper</i> (21.8%) while snail was highest in control (62.8%) and lowest in Maize + soybean + <i>Piper</i> (15.4%). The severity of fall armyworm was highest in control (41.3%) and lowest in Maize + soybean + <i>Piper</i> (12.7%), while that of snail was highest in control (18%) and lowest in Maize + soybean + <i>Piper</i> (4.3%). The maize grain yield differed significantly (<I>P</I><0.05), with the highest in Maize + soybean + <i>Piper</i> (5.2 t/ha) and lowest in Maize + okra (2.8 t/ha). Total nitrogen differed significantly with the highest in Maize + soybean + <i>Piper</i> (0.19%) and lowest in Maize + okra (0.13%). Maize yield was positively correlated with total nitrogen (r = 0.77) and negatively correlated with maize pests (r = -0.73 for FAW, r = -0.76 for snail). Thus maize-soybean intercropping using <i>Piper</i> as insecticide is of high importance and a good sustainable alternative to synthetic inputs for maize pest control, optimizing primary macronutrient and maize yield.