Agronomic potential of some agricultural wastes as surface mulches in hot pepper and tomato production in the Central Region of Ghana

Abstract

Studies were carried out at the Teaching and Research Farm of the University of Cape Coast, in the minor seasons of 1992 and 1993, to assess the agronomic potential of some common agricultural wastes as surface mulches in terms of weed control, nematode population in soil, root-knot incidence and growth and yield of pepper (Capsicum frutescens L.) and tomato (Lycopersicon esculentum Mill.). There were six mulch treatments, namely grass, sawdust, baggasse, palm fruit fibre, chopped palm bunch, corn cob and a no-mulch control arranged in a randomized complete block design with four replications in the pepper trial. Corn cob was not included in the tomato trial which was also replicated four times. Mulching promoted early flowering in both pepper and tomato probably through its reduction of soil surface temperature. Fresh weight of weeds was also significantly reduced by mulching. The degree was, however, related to type of mulch, with bagasse and chopped palm bunch as the best on account of the size and density of the aggregates and compactness of the cover. Even though mulching tended to increase population of nematodes in the soil with time, there was relatively fewer incidence of root-knots in mulched pepper and tomato than in no-mulching. With the exception of palm fruit fibre, mulching significantly increased yields of both crops with bagasse and sawdust being outstanding in this regard. Superiority of the two might derive from their capacity to soak up and conserve more moisture than the rest due to the absorbent nature of their aggregates. Analysis of the nutrient composition of the different mulching materials showed that apart from grass which contained a little more than 1 percent nitrogen, the rest were very low in nitrogen and phosphorus but high in carbon with C:N ratio of over 187:1; that would rather require application of starter fertilizer to compensate for the initial depression of nitrification. (Ghana Journal of Agricultural Science, 1997, 30(1): 45-52)