The effects of pruning and potassium fertilisation rate in the greenhouse production of Scotch bonnet pepper (Capsicum chinense Jacquin)

Two initial studies were conducted to determine the potential for greenhouse production of Scotch bonnet pepper (Capsicum chinense Jacq.). When these peppers are grown outdoors in Jamaica, fruit yield declines over time owing to increasing infections with several aphid-vectored viral pathogens. Production of Scotch bonnet peppers in greenhouses with insect-excluding screens covering the sideand end-walls would render the plants virus-free and would extend the harvest season which is limited by damaging rainfall during the wet season. We found in Delaware, USA (39.68° N) that fruit yields from greenhouse-grown plants were far greater than those expected from field-grown plants in Jamaica. Greater fruit number and weight of marketable fruits per plant were achieved from nonpruned plants compared to those from plants pruned to either of two Dutch V systems [plants pruned to two main stems and subsequent laterals pruned to one (V1) or to three (V3) nodes]. These differences were less pronounced when fruit yield was expressed on a per m-2 basis since pruned plants were closer together (1.8 plans m-2) than non-pruned plants (1.1 plants m-2). Low-K fertilizer (21N-2.2P16.6K) compared to high-K fertilizer (15N-2.2P-20.8K) resulted in a 75% early-season and an 8% full-season increase in marketable fruit fresh weight∙m-2 in non-pruned plants.