Vegetable-based agroforestry is one of the means to diversify from cereal-based intercrops under agroforestry system. Onion (Allium cepa L.) is one of the most important vegetable crops used for consumption in India and the highest foreign exchange earner among the fruit and vegetables. In this context, the current study was carried out to assess the potential of onion varieties under Populus deltoides Bartr. ex Marsh-based agroforestry system. Six onion varieties (POH-1, PRO-6, PRO-7, PWO-2, PYO-1 and Pb Naroya) were evaluated with three planting times (mid-December, end-December and mid-January), under two cropping systems (sole onion and poplar + onion) for two consecutive years during rabi (winter) seasons 2018–19 and 2019–20. Poplar block plantation was established at 8 × 2.5 m with 8 m width in N–S direction. Age of the trees was 4 and 5 years during the respective period of experiment and attained 17.7 cm mean diameter, 15.8 m height and 17.8 m² crown spread. Onion variety PRO-7 transplanted in mid-December gave maximum average bulb weight (62.1, 70.3 g), bulb diameter (5.49, 5.79 cm) and bulb yield (27.59, 37.89 tha⁻¹) under both poplar as well as in open field conditions. This is attributed to the short duration nature of PRO-7 which completes its life cycle before whole development of poplar canopy. NPV and annuity value of poplar + onion-based system was 28% higher than the conventionally followed poplar + wheat model. Benefit–cost ratio was also reported highest for the present model (2.94) as compared to poplar + wheat (2.74) and sole onion (1.92). Thus, growing of suitable onion variety at appropriate time can enhance the income of poplar-based agroforestry system.

在农林业系统下，以蔬菜为基础的农林业是从谷物间作作物多样化的手段之一。洋葱（洋葱Cepa L.）是印度最重要的食用作物之一，也是水果和蔬菜中创汇最高的收入来源。在这种情况下，目前的研究是为了评估在胡杨（Populus deltoides Bartr）下洋葱品种的潜力。基于沼泽的农林业系统。在三个种植时间（12月中旬，12月下旬和1月中旬）进行两次种植，评估了六个洋葱品种（POH-1，PRO-6，PRO-7，PWO-2，PYO-1和Pb Naroya）狂犬病期间连续两年（唯一洋葱和杨树+洋葱）（冬季）2018-19和2019-20赛季。杨树块人工林建立在8×2.5 m，在N–S方向上的宽度为8 m。在各个实验期间，树木的年龄分别为4年和5年，平均直径为17.7厘米，高度为15.8 m，树冠展宽为17.8 m ²。在12月中旬移植的洋葱品种PRO-7的最大平均鳞茎重（62.1，70.3 g），鳞茎直径（5.49，5.79 cm）和鳞茎产量（27.59，37.89 tha ^-1），无论是在杨树还是在野外条件下。这归因于PRO-7的持续时间短，可以在整个杨树冠层发育之前完成其生命周期。基于杨树+洋葱的系统的净现值和年金值比常规采用的杨树+小麦模型高28％。与杨树+小麦（2.74）和唯一洋葱（1.92）相比，本模型的效益成本比（2.94）也最高。因此，在适当的时间种植合适的洋葱品种可以增加基于杨树的农林业系统的收入。