SURESH KUMAR, V. S. HOODA, SATPAL, JAGDISH PARSHAD, ANIL DUHAN, SUSHIL KUMAR, NEELAM1 AND RAM NIWAS
Department of Agronomy,
Department of Genetics & Plant Breeding,
Department of Microbiology,
Department of Chemistry,
Department of Mathematics & Statistics CCS Haryana Agricultural University, Hisar-125 004 (Haryana), India
*(e-mail: sureshsilla@hau.ac.in)
(Received : 11 February 2024; Accepted : 23 March 2024)
SUMMARY
Cluster bean (Cyamopsis tetragonoloba L.) is grown under both rainfed and irrigated conditions in Haryana and weeds pose serious threat to its production under both the conditions. Owing to increasing labour cost, there is need for chemical weed management, but, there is no chemical recommendation for weed management in cluster bean in Haryana. So, a field experiment was conducted during kharif season of 2018 and 2019 at Research Farm, Department of Agronomy, CCS Haryana Agricultural University, Hisar, India in a semi-arid climate. The experiment was laid out in split-plot design having three replications, with three irrigation levels viz., no post-sown irrigation, one irrigation and two irrigations in main plots, while five weed management practices viz., pendimethalin 1.0 kg/ha as PRE, imazethapyr 70 g/ha as PRE, imazethapyr 70 g/ha at 21 DAS, imazethapyr + imazamox (RM) 70 g/ha at 21 DAS and farmers’ practice (2 hand weedings at 3 and 5 WAS) in sub-plots. The cluster bean crop was infested with Cyperus rotundus, Convolvulus arvensis, Digera arvensis and Echinochloa colona. The dry weight of weeds at 60 DAS and at harvest increased with the increasing irrigation levels. Among the weed management practices, two hand weedings at 3 and 5 WAS, produced minimum weed dry weight at 30 DAS, 60 DAS and harvest, while, imazethapyr + imazamox (RM) 70 g/ha at 21 DAS was found most effective in controlling the weeds among the chemical methods. During both the years, maximum seed yield of cluster bean was produced by irrigating the crop with two irrigations (1036 and 726 kg/ha), which was statistically at par with one irrigation (1009 and 682 kg/ha, during 2018 and 2019, respectively). Two hand weedings at 3 and 5 WAS, was found superior to chemical weed control treatments in producing seed yield (1121 and 754 kg/ha during 2018 and 2019, respectively). However, imazethapyr + imazamox (RM) 70 g/ha at 21 DAS produced highest seed yield (968 and 674 kg/ha, during 2018 and 2019, respectively), which was statistically similar to imazethapyr 70 g/ha PRE (932 and 654 kg/ha, during 2018 and 2019, respectively) and both of them were superior to imazethapyr 70 g/ha at 21 DAS and pendimethalin 1.0 kg/ha as PRE. The bacterial and PSB count at harvest of cluster bean crop increased with increase in irrigation levels and bacterial population was lower with soil application of herbicides (either pendimethalin or imazethapyr) as compared to foliar application of herbicides and 2 HW treatments, however, PSB population was not affected by weed management practices. Maximum herbicide residue at harvest of the cluster bean crop was found in imazethapyr 70 g/ha at 21 DAS and followed by imazethapyr 70 g/ha PRE and imazethapyr + imazamox (RM) 70 g/ha at 20 DAS. Reduction in the germination, growth and yield of mustard was observed due to residual effect of the chemicals applied in cluster bean during both years of study, maximum being with imazethapyr 70 g/ha at 21 DAS followed by imazethapyr 70 g/ha PRE and imazethapyr + imazamox (RM) 70 g/ha at 21 DAS.
Key words: Cluster bean, mustard, irrigation, weed management, herbicide residue