Effects of seedling age and potassium fertilizer on growth and yield of summer onion

Abstract

An experiment was conducted at the Horticulture Farm of Bangladesh Agricultural University, Mymensingh to assess the effects of seedling age and potassium fertilizer to improve summer onion production (cv. BARI Piaj-3). The experiment consisted of two factors; Factor A: three seedling age, viz. 35; 40 and 45 days old and Factor B: four different doses of potassium, viz. 0; 40; 80 and 120 kg/ha-1. The experiment was laid out in a randomized complete block design with three replications. The effect of different seedling age and potassium fertilizer and their combined effects showed significant variations in growth and yield of onion. In case of seedling age, the highest plant height (56.58 cm), leaf number (12.37) per plant, leaf length (41.77 cm), yield of bulb per plot (1.96 kg) and yield of bulb (19.64 t/ha) were recorded from 45 day old seedling. In case of different doses of potassium, the highest plant height (58.82 cm), leaf number per plant (13.93), leaf length (43.69 cm), yield of bulb per plot (1.90 kg) and yield of bulb (19.00 t/ha) were recorded from 120 kg K ha-1. Combined effects of seedling age and potassium fertilizer exhibited significant variation on plant height at different days after transplant (DAT), leaf number per plant, leaf length, bulb diameter, pseudostem diameter, fresh weight of bulb, dry weight of bulbs, fresh weight of foliage, dry weight of foliage, yield of bulbs per plot and yield of bulbs (t/ha). The highest bulb yields per plot (2.31 kg) as well as per hectare (23.05 tons) were achieved from the treatment combination of 45 day old seedling and 120 kg K ha-1.