Mohanvel P., Srinivasa Perumal A.P., Sundari A., Thiruppathi M. and Srinivasan S.
Abstract
Chemical weed management in maize is the affordable method in control of weeds in maize than hand weeding. However, spraying operations has many disadvantages like spray drift, difficult during rainy days and needs labour. Hence, herbigation becomes the promising method in delivering the herbicides through drip irrigation. Thus, AField experiment was conducted during kharif season of 2022 at Annamalai University, Cuddalore, Tamil Nadu to evaluate the Impact of herbigation on weed dynamics and soil microbial population in hybrid maize. The experiment was laid out in Randomized block design (RBD) with three replications. In this investigation, totally twelve treatments were comprised viz., T1- Control (Unweeded), T2- Hand weeding (on 20 & 40 DAS), T3- Pendimethalin 30% EC @ 0.75 kg a.i ha-1 herbigation as PE, T4- Mesotrione 40% SC @ 90 g a.i ha-1 herbigation as PE, T5- Pendimethalin 30% EC @ 0.75 kg a.i ha-1 herbigation as PE fbTembotrione 34.4% SC @ 110 g a.i ha-1spraying as PoE, T6- Pendimethalin 30% EC @ 0.75 kg a.i ha-1 herbigation as PE fb Topramezone 33.6% SC @ 30 g a.i ha-1spraying as PoE, T7- Mesotrione 40% SC @ 90 g a.i ha-1 herbigation as PE fb Tembotrione 34.4% SC @ 110 g a.i ha-1 spraying as PoE,T8- Mesotrione 40% SC @ 90 g a.i ha-1 herbigation as PE fb Topramezone 33.6% SC @ 30 g a.i ha-1spraying as PoE, T9- Pendimethalin 30% EC @ 0.75 kg a.i ha-1 herbigation as PE fb Tembotrione 34.4% SC @ 110 g a.i ha-1 herbigation as PoE, T10- Pendimethalin 30% EC @ 0.75 kg a.i ha-1 herbigation as PE fb Topramezone 33.6% SC @ 30 g a.i ha-1 herbigation as PoE, T11- Mesotrione 40% SC @ 90 g a.i ha-1 herbigation as PE fb Tembotrione 34.4% SC @ 110 g a.i ha-1 herbigation as PoE, T12- Mesotrione 40% SC @ 90 g a.i ha-1 herbigation as PEfb Topramezone 33.6%SC @ 30 g a.i ha-1 herbigation as PoE. The maize hybrid DKC 9178 was used for the study. Among the herbicidal treatments, maximum weed control efficiency and weed control index were achieved with the treatment of PE application of Mesotrione 40% SC @ 90 g a.iha-1on 3DAS Herbigation + PoE application of Tembotrione 34.4% SC @ 110 g a.i ha-1 on 21DAS spraying which is at par with the twice hand weeding. At the initial stages of the study (before herbigation) there was no significant difference among the microbial population. But after the application of herbicides through drip there shows a setback in the population and shows significant difference among the microorganisms in the soil. However, the snag in the microbial population was recovered in the 60 DAS.