Yield of garden peas—field responses to variation in sowing rate and irrigation

Abstract

Garden peas (cv. Victory Freezer) were grown over 2 seasons on a Wakanui silt loam at 5 plant densities: 83, 109, 135, 178, and 228; and 65, 101, 130, 163, and 199 plants/m2in the 2 respective seasons. Two moisture treatments, dryland, and irrigated at flowering and pod swelling, were also used. Irrigation increased green pea yield by 84% and seed yield by 78% in the first year because of increases in pods/plant, peas/pod, and pea weight. Water also increased vine length and weight, and harvest index. In the second year, seed yields increased by 33% with irrigation. The effect of plant density on yield was much less than irrigation as a result of increasing plant numbers being largely nullified by a major decrease in pods/plant, peas/pod, and pea weight. In the first season, green pea yield without irrigation did not increase significantly beyond 83 plants/m2but with water, 135 plants/m2were significantly higher in yield. Seed pea yield did not respond to changing plant density in that year, but in the second season higher yields occurred at 101 plants/m2compared with 65 plants/m2, under both dryland and irrigated conditions. Yields reached 10.5 and 5.2 t/ha of green and seed peas respectively under optimum irrigation and plant density. Practical recommendations on optimum plant population densities are given. © 1988 Taylor … Francis Group, LLC.