GROWTH AND YIELD OF ONION IN RESPONSE TO PLANT DENSITY AND BIOFERTILIZER

Abstract

An experiment was carried out at a research field of Horticulture Farm, Sher-e-Bangla Agricultural University, Dhaka, during the period from November 2021 to April 2022 to find out the integrated effect of planting density and different level of biofertilizer doses on the growth and yield of onion. The experiment was laid out in two factorial RCBD with 3 (three) replications. Factor A (Different Planting Distances) viz. S 0 = 30 cm × 20 cm; S 1

= 30 cm × 15 cm; S 2 = 30 cm × 10 cm and Factor B (Biofertilizer Doses) viz. F 0 = Recommended Doses of Fertilizer (RDF) of NPK; F 1 = 1 2 RDF of NPK + 2 kg/ha Biofertilizer, F 2 = 1 2 RDF of NPK + 4 kg/ha Biofertilizer and F 3 = 1 2 RDF of NPK + 6kg/ha Biofertilizer. Activer was used for biofertilizer doses which contains a combination of Rhizobium, Phosphobacter, Trichoderma & Lactic Acid Bacteria. Significant variation was found in all parameters due to the effect of different plant density and different amount of biofertilizer application. In case of plant density, the maximum yield (11.14 t ha ) was recorded from the favorable plant spacing i.e. 30 x 15 cm (S 1 ) due to higher number of bulb obtained per hectare land followed by S 2 treatment. One the other hand, the minimum yield (8.72 t ha -1 ) was recorded from the broader plant spacing i.e. 30 x 20 cm (S 0 ) due to lower number of plant obtained per hectare land. The highest bulb yield (12.08 t ha ) was recorded from the plot where 1 2 RDF of NPK + 4 kg/ha Biofertilizer (F 2 ) was applied which was followed by 1 2 RDF of NPK + 6 kg/ha Biofertilizer (F 3 ) treatment. On the other hand, lowest bulb yield of 7.99 t ha -1 was obtained from the plot where only the recommended dose of NPK (F 0 ) was applied. The maximum yield (13.54 t ha -1 ) was recorded in the plot where optimum plant spacing of 30 x 15 cm was maintained with 4 kg ha biofertilizer (S 1 F 2 ), and the minimum yield (6.48 t ha -1 ) of bulb was recorded in the plot where a broader spacing of 30 x 20 cm was maintained with no biofertilizer (S 0 F 0 ). The findings of the present investigation clearly indicates that the integrated use of optimum planting distance and optimum level of biofertilizers for growing onion bulb is a viable option for improved cultivation.