Transparent, Black and Organic Mulches Effect on Weed Suppression in Green Pepper (Capsicum annuum) in Western Kenya

Abstract

Weed suppression through physical methods in cultivation constitutes of many methods but this experiment focused on application of various mulches. Recently, herbicide-free weed control methods in the world are getting more attention due to environmental and ecological factors. Green pepper production requires good management practices in order to attain potential yields. Most of the known physical practices of weed control cause both positive and negative effects. Therefore, great attention should be paid when selecting the appropriate mulch with the aim of weed suppression in any specific cultivation. Three types of mulches were examined for weed control namely; black plastic mulch, transparent plastic mulch, straw mulch and bare soil as control during the 2015 short and long raining seasons in Busia County. In both seasons, the black plastic mulch treatment significantly (P<0.05) showed the lowest number of weed species (3) per m² quadrat while the control had the highest with a maximum of 8 and 7 during the long and short raining seasons respectively. The number of species reduced after four weeks from transplanting when the first sampling was carried out. The lowest weed vigor was exhibited in the plastic treatments for both seasons at 4, 6 and 8 weeks after transplanting. Control had the highest weed fresh biomass for both seasons at all the sampling stages with the highest observed during the short raining season with 1626 g/m² at 4 weeks after transplanting. This also translated to the highest weed dry biomass for both seasons in the control plots with the lowest recorded in the black plastic mulch. Out of several physical methods of weed control, mulching seems to be the most appropriate with the black plastic mulch being the best.