Irrigation Management for Optimizing Onion Seed Production

Onion is seen as a major horticultural crop in Bangladesh. Irrigation technologies that conserve water are necessary to assure the economic and environmental sustainability of commercial agriculture. This study was conducted in Lysimeter to observe the effect of different irrigation regimes on onion seed and bulb yield. Irrigation regime consisted of five irrigation treatments: Irrigation at pre-vegetative stage up to field capacity [T1]; Irrigation at pre-vegetative and vegetative stage [T2]; Irrigation at pre-vegetative, vegetative stage, and bulb formation stage [T3]; Irrigation at pre-vegetative, vegetative, bulb formation, and flowering stage [T4]; and Irrigation at pre-vegetative, vegetative, bulb formation, pre-flowering, and late flowering stage [T5] up to field capacity. The results revealed insignificant effect on seed and bulb yield, and yield attributes except plant height. The cultivars showed significant effect on all yield attributes and seed yield of onion. The highest seed yield (76.98 gm.m-2) as well as water productivity (33.95 kg ha-1 cm-1) was obtained from T4 treatment, which received four irrigations (total 11.06 cm). The onion mutants produced higher seed yield than the check cultivar Baripiaj 2. The highest seed yield was found under Bp2/75/2 mutant (73.93 gm/m2). From the present results, it is revealed that irrigation at pre-vegetative, vegetative, bulb formation and flowering stages up to field capacity are required for higher seed yield of onion at Mymensingh area.