Impact of agronomic approaches in optimizing weed control and productivity of black gram [Vigna mungo (L.) Hepper]: A review

Black gram [Vigna mungo (L.) Wilczek], also known as urd bean, is an essential part of the daily diet since it is a rich source of protein. Weeds are one of the major factors limiting the production of black gram as the reduction in yield of black gram due to weed infestation is 45-70%. In black gram, the first 30 days are crucial for crop weed competition. Different strategies incorporating non-chemical and chemical methods have been practiced for efficient weed control in black gram. Non-chemical methods, such as row spacing, timing of hand weeding, tillage practices, etc., which not only controls the weed population but also improves the soil properties. Herbicides with varying degrees of selectivity and efficacy that are available for use in black gram are among the chemical control options. Herbicides (pre- and post-emergence) should be used at the recommended rate and time for effective weed control to prevent suppression of growth, grain yield and symbiotic properties, i.e., number of nodules, dry weight of nodules and leghaemoglobin content in nodules of black gram crop. This review covers the several weed management techniques, such as chemical and non-chemical weed control methods and evaluates how well they work to control weeds in black gram. Additionally, their impact on soil microbiology, black gram yield, symbiosis and growth, as well as any leftover effects on subsequent crops have all been evaluated in this review.