Response of Cowpea [ Vigna unguiculata (L.) Walp.] as Succeeding Crop to Residual Effect of Extreme Levels of Atrazine Administered in Preceding Maize (Zea mays L.)

Background: Globally, grain legumes are the paramount family of agricultural crops following cereals. Generally, sequence cropping has manifested effectual in increasing farm productivity and profitability. However, sometimes herbicides administered in previous crop may be associated with phytotoxic effects that can later cause damage to the succeeding crops. The present study aimed to understand the residual effect of extreme levels of atrazine on succeeding cowpea under maize-cowpea cropping system. Methods: Field experiments were conducted during Kharif and rabi season of 2019-20 and 2020-21 in a randomized block design with eleven treatments, replicated thrice. Result: Residual effect of pre-emergence atrazine at 0.50 kg a.i ha-1 followed by tembotrione at 120 g a.i ha-1 as post-emergence at 25 DAS recorded the lowest total weed density (4.41), total weed dry weight (9.81 g m-2)-2 ) and highest weed control efficiency (39.25%) during rabi 2019-20 while during rabi 2020-21 lowest total weed density (5.03), total weed dry weight (10.68 g m-2)-2 ) and highest weed control efficiency (39.65%) were noticed in pre-emergence atrazine 50% WP at 2.00 kg a.i ha-1 . Highest seed yield (788.67 and 842.33 kg ha-1 ) was obtained in weed free treatment.