Studies on the Technique of Seed Multiplication for Onion
II. A Study of Plant Density on Onion Seed Production
M. T. Chang and H. Yu
Onion bulbs were planted for seed production. Results showed that more seeds were harvested with increasing plant density.
Plant density of 40 cm × 30 cm and 40 cm × 20 cm were the highest; 50cm × 30 cm and 50cm × 20cm or 80cm × 30cm and 80cm × 20cm were the second; 100cm × 30cm and 100cm × 20cm were the lowest in seed yield. Plants grow in high density were more uniform in developing, bolting and fewer in missing plant than those grow in low density.
High plant density of 40cm × 30cm, 40cm × 20cm, 50cm × 30cm and 50cm × 20cm caused more problems in planting, cultivation, fertilizing and weed control. Cultural practice was easier in low plant density system. However, this would cause land waste and lodging or broken of umbels.
According to cultural practice, plant growth, seed production and economic point of view, the recommend plant density for onion seed production is 80cm × 30cm or 80cm × 20cm.