Influence of weed management practices on weed dynamics and yield of urdbean (Vigna mungo) under rainfed conditions of Jammu

Experiments were conducted during kharif 2007 and 2009 in Inceptisols, to study the effect of different pre (PE) and post-emergence (POE) herbicides along with two hand weedings (HW) at 20 and 40 days after sowing (DAS) and weedy check on urdbean {Vigna mungo (L.) Hepper}. Highest seed yield was observed with two HWs at 20 and 40 DAS and the values were found statistically at par with POE application of imazethapyr 25 g/ha at 20 DAS. The highest weed control efficiency and lowest weed biomass was recorded with two HWs at 20 and 40 DAS followed by application of imazethapyr 25 g/ha (post-emergence) at 20 DAS. Application of Fenoxaprop-p-ethyl, quizalofop-p-ethyl, chlorimuron-p-ethyl as post-emergence and their combinations also reduced weed biomass and improved seed yield and yield attributing parameters as compared to weedy check. Treatment weedy check registered the highest values of weed count and weeds biomass and lowest seed yield and yield attributing characters in both the years of study. Rainfall was directly related to weed count and weed dry matter accumulation with the coefficient of 0.65 and 0.61, respectively. Weed dry matter accumulation was directly related with sunshine hours with an accuracy of 67%, whereas, weed count was lesser related with sunshine hours of the day with an accuracy of 34%. Grain and biological yield of urdbean crop decreased at the rate of 3.3 and 7.5 kg/ha under weedy check with an accuracy of 88 and 73%, respectively.