Effects of plant spacing and initial-growth of seedlings after transplanting on the uniformity of cabbage heads at harvest.

摘要

The effects of planting densities of cabbage plug transplants in the field on the uniformity of their initial growth and head size at harvest were investigated. Head size uniformity decreased with small within-row spacing (WRS) from the beginning ofhead formation. Unevenness of initial-growth of high-density transplants resulted in a decrease of uniform head size at harvest. This lack of uniformity is attributed to the initial differences in growth which increased with time. Retarding harvest timedid not improve growth uniformity. Gaps within the row and the slow growth of some plants promoted the growth of adjacent plants. This tendency was strong under high densities. Hence, growth uniformity was decreased with time. Head size uniformity at harvest decreased when WRS was small. The degree of the decrease was controlled by the initial-growth uniformity of transplants. Thus, we conclude that avoiding the creation both of gaps and of underdeveloped stock in the field is indispensable to maintaining head uniformity under dense planting conditions of about 30-cm WRS. Producing uniform transplants and promoting the establishment of transplants are important to obtain uniform cabbage head size at harvest.