The effect of plant density, date of apical bud removal and leaf removal on the growth and yield of single-harvest Brussels sprouts (Brassica oleraceavar. gemmifera D.C.): III. The components of marketable yield

Abstract

SummaryAn analysis of marketable yield of sprouts is suggested in which the components are: number of plants/m3, number of buds/plant, acceptable size fraction, acceptable quality fraction and mean weight per marketable bud.The number of buds per plant was dependent on date of stopping but was not greatly affected by plant density. This component was not found to limit yield.Acceptable size fraction was related to the standard deviation of bud size and increased to a maximum at the time of optimum bud size. The maximum acceptable size fraction obtained from field samples could be reliably predicted from measurements of the standard deviation of bud size.The acceptable quality fraction was of particular importance in later harvested crops and at higher plant densities. It was highly dependent upon cultivar but was little affected by stopping treatment. Unacceptable buds occurred most frequently at the base of the stem and it is argued that the importance of the blemishing diseases responsible for these losses has been increased by the single-pick harvesting technique.The optimum plant density was related to the expected date of harvest but the practice of delaying maturity by increasing density is limited by the decreased acceptable quality fraction. Crops for harvest in October and November should undoubtedly be stopped both to reduce bud size variation and to stimulate bud growth.