Abstract

                                Field experiment was conducted to find out the effect of pre-emergence(PE) and early post-emergence (EPoE) herbicides on weed control inirrigated blackgram at College of Agricultural Technology, Kullapuram- Theniduring 2015-2016. In this experiment, weed management practice of preemergenceapplication of Pendimethalin 30 EC 1.0 kg a.i. ha-1 at 3 daysafter sowing (DAS), early post-emergence application of Quizalofop ethyl@50 g a.i. ha-1 at 15 DAS, early post-emergence and Imazethapyr each @50 g a.i. ha-1 at 15 DAS and their combinations of Pendimethalin @ 1.0 kgha-1 at 3 DAS followed by either Quizalofop ethyl or Imazethapyr each @50 g a.i. ha-1 were tested against hand weeding twice at 20 and 40 DAS,weedy check and weed-free check as controls in randomized block designreplicated thrice. Among the different weed management practices, preemergenceapplication of Pendimethalin 1.0 kg a.i. ha-1 (3 DAS) followedby Imazethapyr @ 50g a.i. ha-1 as EPoE (15 DAS) recorded relatively lesserproportion of broad-leaved weeds (30.90 and 49.16%) and higher WeedControl Efficiency (WCE) of 91.27 at 60 DAS. Application of pendimethalin1.0 kg a.i. ha-1 PE (3 DAS) followed by Imazethapyr @ 50g a.i. ha-1 as EPoE(15 DAS) registered significantly taller plants (42.22 cm), higher dry matterproduction(2649 kg ha-1), more number of pods per plant (44.19), seedsper pod(5.57) and higher grain yield (1052 kg ha-1). Thus, pre-emergenceapplication of pendimethalin 1.0 kg a.i. ha-1 (3DAS) followed by Imazethapyr@ 50g a.i. ha-1 as EPoE (15DAS) recommended as effective and economicweed management practices on the basis of better weed control, crop growth,and yield of irrigated blackgram.

Key words : Pendimethalin, Imazethapyr, Quizalofop ethyl