Chemical Science Review and Letters ISSN 2278-6783 Chem Sci Rev Lett 2018, 7(25), 77-82 Article CS292049121 77 Research Article Bioefficacy of Herbicides in Relation to Planting Techniques in Wheat Sudesh Devi*, Virender Singh Hooda, Navish Kumar Kamboj and Jagdev Singh Department of Agronomy, CCS Haryana Agricultural University, Hisar, Haryana-125004 Introduction Wheat, in India, is second most staple crop grown after rice; its production increased from a mere 11 million tons during 1960-61 to 97.4 million tons during 2016-17 [1]. Rice-wheat rotation is the principal cropping system in the Indo-Gangetic plains with more than 13.5 m ha area under its cultivation. The wheat is considered most assured crop in the country which is essential for our food security, but there are many biotic and abiotic factors responsible for stagnation of wheat productivity under rice wheat cropping system in last decade. The high nutrient and water requisite along with less aggressive nature of the high yielding varieties have provided favorable environment for weed infestation [2], which caused about complete failure of crop in extreme cases [3]. Among different improved package of agronomic techniques, optimal row spacing is one of several important agronomic approaches that can be used to boost up the wheat productivity by optimizing the capacity of tillering of wheat and efficient utilization of other available resources [4, 5]. Inefficient utilization of available sources by plants, particularly solar radiation under a wider row spacing, and severe inter-row competition among plants in narrow rows have compelled researchers to optimize proper row spacing for attaining better production of different crops and even varieties within the same species [5, 6]. Optimum row spacing ensures better light interception and penetration into the crop canopy and enhances light utilization efficiency in crop plants [7]. Bed planting method improves water use efficiency, lowers seed rate, reduce crop lodging, production cost and fuel consumption, and control root diseases [8-10]. Because of higher economic cost of labour for manual weeding and its lower efficacy, farmers are relying heavily on herbicides for effective weed control in different crops including wheat. With the changing pattern of social living and work culture along with intensified agriculture, chemical weed control has become an unavoidable necessity in crop production. The weeds showed multiple herbicide resistance due to continuous use of herbicide having same mode of action and/or class [11]. Now a day, herbicide resistance is becoming the major cause of yield losses in crops. Therefore, effective weed management requires an integrated approach using both chemical and non-chemical approaches. The number of market entry of herbicides with new mode of action has reduced. For effective management of complex weed flora, there is need to use mixture of existing herbicides, which should have a wide spectrum of weed control without crop injury and residual effect on succeeding sensitive crops after wheat [12, 13]. Herbicides mixture increases weed control efficacy against complex weed flora [14], and also helpful in delaying herbicide resistance [15]. Integration of improved agronomic practices along with chemical methods will help in increasing the life of existing herbicides and make the weed management cost-effective and efficient. The present study was conducted to assess the effects of different planting techniques and herbicides on weed and wheat productivity. Abstract A field experiment was conducted to understand the effect of planting techniques and herbicides on weed management and wheat productivity in split plot design with three replications. The planting techniques had no effect on total weed density, weed control index, weed index, weed persistence index and crop resistance index. Drill sowing at 18 cm recorded maximum LAD, NAR and yield than other planting techniques while lowest total weed density was recorded in 16 cm row spacing. The tank mix application of pinoxaden (50 g/ha)+RM of carfentrazone and metsulfuron (25 g/ha) recorded lowest total weed density, weed index and weed persistence index, and highest value of weed control index, crop resistance index and yield over other herbicidal treatments. To obtain higher yield, drill sowing at 18 cm combined with tank mix application of pinoxaden and RM of carfentrazone and metsulfuron should be practiced. Keywords: Planting Techniques, Herbicide treatments, weed control, wheat productivity, LAD, NAR *Correspondence Author: Sudesh Devi Email: drmalik107@gmail.com