Growth and seed yield of onion (Allium cepa L.) cv. Sukhsagar as influenced by different sowing spacing of bulbs

A study “Growth and seed yield of onion (Allium cepa L.) cv. Sukhsagar as influenced by different sowing spacing of bulbs” was conducted in the Horticultural Research farm of Bidhan Chandra Krishi Viswavidyalaya, Mohanpur, Nadia, West Bengal, which is situated at 23Âo5´ N latitude and 80Âo02´ E longitudes with an elevation of 9.75 meter from the sea level and a distance of about 100 km in north of the capital city of West Bengal, Kolkata having well connected with road (NH-34) during the year 2016 to 2017. The purpose of the study was to evaluate the effect of different sowing spacing of onion bulbs on plant growth and quality seed production of onion. Onion variety “Sukhsagar Local” with three different sowing spacing (S1 : 30 cm x 30 cm, S2 : 40 cm x 30 cm, S3 : 50 cm x 30) had a remarkable impact on seed yield, yield attributes and seed quality. Plant height, number of leaves per plant, length of scape, number of umbles per plant, umble diameter, seed yield per plant, germination percentage and electrical conductivity were positively influenced by bulb size of onion. It was revealed that the wider spacing of 50 x 30 cm gave larger numbers of umbels per plant than the umbels sown closer (30 x 30 cm) and medium (40 x 30 cm)ones. Closer bulbs gave lowest umbel diameter with smaller inflorescences than the medium and wider planted ones. The bulb size also did not affect seed yield per one seed stalk, but it did affect the seed yield obtained from the entire plant, which was bigger for plants grown from wider planted bulbs in comparison with the closer ones. Bulb spacing showed significant effects on growth and yield. Thus, as closer planted, the number of flower stalks per bulb decreased, as did in seed production per plant and per hectare. The closer planting (30 x 30 cm) gave the highest net return with a maximum benefit cost ratio.