Spacing experiments with brussels sprouts grown for single-pick harvests.

Abstract

Two-year trials are discussed on the effects of different spacings, planting pattern and row orientation, stopping the plants, and time of harvest on the cropping, habit and root growth of the hybrid brussels sprouts variety Thor. Yields of dry matter per sq.m. rose sharply with increasing plant density up to about 4 plants per sq.m., above which there was little further increase. The average weight per plant, however, showed the reverse trend, and declined with closer spacing. The total yields of sprouts from unstopped plants attained a maximum at a density of about 1 plant per sq.m., but the maximum yields and numbers of marketable sprouts were obtained with densities of about 2 and 2 plants per sq.m., respectively. Plants grown at high densities were taller and more slender than low-density plants, a habit well suited to mechanical stripping. Moreover, the sprouts from high-density plants were more uniform, which facilitated grading. There was little difference between the number and distribution of the roots, including depth of rooting, over a wide range of plant densities. However, high-density plants had fewer thick roots, and at the widest spacings the total number of roots per sq.m. declined. The pattern of planting had a slight influence on the height of the low-density plants, but differential effects of various row orientations were negligible. Stopping the plants greatly increased the total yields of sprouts at all densities; the numbers of marketable sprouts from the stopped plants were also greater, especially at densities of 3 plants per sq.m. and above. Harvesting stopped plants in late October instead of late September resulted in much higher yields of sprouts at all densities except the lowest, despite a decline in the fresh weights of the plants during this period.-I.T.T., Wageningen. (Abstract retrieved from CAB Abstracts by CABI’s permission)