A.P. Everaarts

Yield formation in Brussels sprouts

SummaryThe effects of three planting dates and three plant densities, covering most of the planting dates and densities used in the Netherlands, on yield determining factors of Brussels sprouts (Brassica oleracea var. gemmifera), were studied in field experiments during three seasons. Planting dates were between the end of April and early July. Plant density ranged between 2.7 and 4.4 plants per m2. Planting late in the season initially resulted in more leaves being formed, a higher Leaf Area Index and a longer stem. During crop growth this trend was reversed to a lower number of leaves formed, and in two of the three years a lower LAI and stem length when planting was delayed. The effect of plant density on these characteristics was generally either less pronounced than that of planting date or was absent. There was no, or only limited, interaction between the effects of planting date and plant density on these characteristics. The initial rate of dry-matter accumulation after planting was higher after p...

The effect of planting date and plant density on yield and grading of Brussels sprouts

SummaryDuring three seasons the effects of planting date and plant density, and their interaction, on marketable yield and grading of Brussels sprouts (Brassica oleracea var. gemmifera) were studied in field experiments. The marketable yield, as an average of three or four successive mechanical harvests, decreased with delay in planting from the end of April–early May to the end of June–early July. Final marketable yield levels varied between 29.4 tonnes per hectare when planting was early, to 17.4 tonnes per hectare when planting was late in the season. A decrease in yield with an increase in plant density from 2.7 to 4.4 plants per m2 was found in only one year. Grading (percentage of buds a31mm) was not consistently influenced by planting date, but increasing the plant density increased the proportion of small buds. There were no or interactions of only limited importance between the effects of planting date and plant density on yield and grading, indicating that, within one year, for the whole range o...