Effects of planting date on growth and yield of pigeon pea (Cajanus cajan(L.) Millsp.)

Abstract

SummaryTwo dwarf pigeon pea cultivars, each at two spacings, were planted at 4-weekly intervals over a year. Differences in height and number of branches between cultivars and spacings were generally small but planting date had much greater effects. Heights at reaping were > 2 m in plantings made in March or April, but decreased with later planting toca. 1 m in November–February plantings. Time from planting to reaping varied fromca. 120 days in September-February plantings to > 225 days in March or April plantings. Four of the 13 plantings showed loss of mainstem dominance. Defoliation by rust disease showed no seasonal pattern, nor any association with yield. March plantings showed a ‘preliminary’ flowering in which only some wide-spaced and perimeter plants flowered in late July. Yields varied from 0–5 to 10 t/ha as green pods, but one cultivar at a spacing of 0·45 × 0·45 m (49385/ha) gave a mean yield ofca.5 ±0·57 t/ha. Late-May planting appeared the most efficient, giving a large number of pods per day, per flowering branch and per metre of height, but plants exceeded 2 m in height and took 200 days from planting to reaping. December or January planting gave smaller plants, takingca. 125 days from planting to reaping. Day-length was a dominant factor influencing growth and yield, but part of this may have been a response to radiation rather than to photoperiod.