Published online by Cambridge University Press: 03 October 2008
Plant population studies were carried out in 1963 and 1964, including row spacing of 75 cm at different within-row densities, for purposes of comparison with the common practice of drilling at 15 cm spacing. Planting in spaced rows 75 cm apart, with increasing intra-row density from 55 to 175 seeds per metre of row, increased seed yield compared with drilling and a high intra-row density was better than low intra-row density for seed yield. The increase in seed yield was due to a higher number of stems, flowers and pods per unit area, and to a higher number of flowers forming mature pods. Seed set was better in spaced rows than at drill-spacing. Flowering took place over a shorter period, and the peak was attained earlier, at higher within-row density. Plant competition influenced plant branching as early as sixteen days after emergence. The relation between seedling development and seed yield is discussed.