Agricultural Research Journal

Onion being one of the important vegetable crops of India, can play a major role in improving the productivity of vegetable-based agroforestry system. A two year study (2016–17 and 2017–18) was conducted to find out the effect of planting time on performance of onion varieties intercropped with 2-and 3-year-old poplar (Populus deltoides) block plantation (8 x 2.5 m spacing). Four onion varieties (Pb Naroya, PRO 6, PWO 35 and PRSC 10) were transplanted at three planting times (end-December, mid-January and end-January) under two growing environments (poplar and open field). The trees attained average height, diameter and crown spread of 12.8 m, 13.1 cm and 21.1 m², respectively, at the age of three years. The average total bulb yield was recorded higher under two-year-old poplar plantation (189.5 q/ha) as compared to three-year-old plantation (175.5 q/ha). There was 42.3 per cent reduction in average total bulb yield of onion under 3-year-old poplars than open conditions. The highest bulb diameter, fresh bulb weight and bulb yield were obtained in end-December planted crop than the other planting times. The onion variety PWO 35 (212.7 and 198.0 q/ha), recorded significantly higher bulb yield than Pb Naroya, PRO 6 and PRSC 10 under 2-and 3-year-old poplars.