Comparative Efficacy of Different Herbicidal Combinations on Weed Growth and Yield Attributes of Wheat

Weeds are the main biotic obstacles on wheat production, which can impair wheat productivity by up to 60%, if not handled under critical stages of crop life cycle. Chemical weed control through herbicides has been the most popular and effective method among farmers. The weed management using similar herbicides however has led to herbicide resistance in weeds. This requires the evaluation of newer herbicidal combinations for the control of weeds in wheat. Therefore, an experiment was conducted at Research Farm, Department of Agronomy, JNKVV, Jabalpur, Madhya Pradesh during the Rabi season of 2016-17 to evaluate the effect of post emergence application of herbicides on the weeds and yield of wheat. The experiment was laid out in randomized block design with ten treatments comprising of eight herbicidal combinations along with a hand weeding and a weed check and replicated thrice. Observations on different weed parameters, growth parameters and yield of wheat were recorded. Among the different herbicidal combinations, the post emergence application of halauxifen-methyl ester + florasulam at 10.20 g/ha resulted in greatest suppression of weeds and had highest weed control efficiency (56.73%). It also led to highest growth in wheat which resulted in highest grain yield (5.81 t/ha) and harvest index (44.99%). From this study, it can be concluded that the post emergence application of halauxifen-methyl ester + florasulam at 10.20 g/ha can not only control weeds effectively but also increase the yield of wheat.

Performance of Pinoxaden Herbicide against Complex Weed Flora in Wheat (Triticum aestivum L.)

A field experiment was conducted during rabi season (2020-21) at AICRP on Wheat, College of Agriculture, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur (MP), India, to study the effect of pinoxaden on weeds and the yield of wheat. The field experiment was laid out in a randomized block design with seven treatments and replicated thrice. Treatments included applying different doses of pinoxaden at 40, 45, and 90 g a.i. ha-1, clodinafop propargyl at 90 g a.i. ha-1, sulfosulfuron at 25 g a.i. ha-1 as post-emergence along with hand weeding at 30 DAS and weedy check. The experimental field was dominated by Phalaris minor (15.6%) among monocot weeds, while Medicago denticulata (30.82%), Cichorium intybus (29.94%), Chenopodium album (15.32%), and Anagallis arvensis (8.30%) among the dicot weeds throughout the crop growing period. Among the different herbicidal treatments, pinoxaden at 90 g a.i. ha-1 effectively controlled the monocot and dicot weeds and recorded higher weed control efficiency and the lowest weed index. However, the highest value of growth parameters, yield attributes, and grain yield was recorded with the application of pinoxaden at 45 g a.i. ha-1 among all the herbicidal treatments.

Weed Dynamics of Fodder Maize as Influenced by Different Herbicides

The advancements in fodder maize cultivation practices over the past few years, has paved a change in the makeup of weed associations. This made it necessary to incorporate new, effective herbicides in the struggle against maize's primary weeds. Therefore, a field experiment was conducted at Research Farm, AICRP on Forage Crops, Department of Agronomy, JNKVV, Jabalpur (Madhya Pradesh) during Kharif season 2019 to devise an appropriate combination of herbicides required for the control of the complex weed diversity in fodder maize. The field experiment was laid out in randomized block design (RBD) with ten treatments (eight herbicidal combinations along with hand weeding twice at 20 and 40 DAS and a weedy check) and replicated thrice. Observations were recorded on the weed parameters and fodder yield of maize. Among monocots, the experimental field was infested with Echinochloa colona, Commelina communis and Digitaria sanguinalis. Phyllanthus niruri and Eclipta alba were dominated among dicots. Among all herbicidal treatment, topramezone 35 g/ha plus atrazine 250 g/ha was found to be significantly superior in reducing total weed density (9.49/m2, 11.50/m2) and total weed dry weight (6.43 g/m2, 7.91 g/m2) at 30 and 45 DAS, respectively and recorded the lowest weed index (1.82%). Also, the maximum green fodder yield (472.68 q/ha) was recorded in topramazone 35 g/ha + atrazine 250 g/ha compared to other treatments. Overall, this study indicated that the combination of topramazone 35 g/ha + atrazine 250 g/ha could be an alternative approach to hand weeding and alone herbicides in fodder maize.

Effect of Mesotrione 40% SC on Weed Growth, Yield and Economics of Maize (Zea mays L.)

Newer herbicides are required to reduce the losses cause by the weeds in maize crop. Therefore, a field experiment was conducted during kharif 2019 at Research Farm, AICRP on Forage Crops, Department of Agronomy, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur (Madhya Pradesh) to study the effect of different weed management practices on productivity of Maize (Zea mays L.). The experiment was conducted in randomized block design with eight treatments (six herbicidal treatments with hand weeding twice at 20 and 40 DAS and weedy check) replicated thrice. Observations were recorded for various weed parameters and crop growth parameters. All the weed management treatments significantly reduced the total weed density and total dry weight of weeds as compared to weedy check. Among herbicidal treatments, mesotrione 350 g ha-1 recorded the lowest total weed density and total dry weight of weeds as compared to other herbicides. While highest total weed density and total dry weight were recorded under weedy check treatment. Significantly higher growth parameters and yield attributing traits were recorded with the application of mesotrione 350 g ha-1 which resulted in higher grain and stover yields (2447.22 and 21804.72 kg ha-1) followed by mesotrione 300 g ha-1. Maximum net returns and Benefit: Cost ratio was also obtained with the application of mesotrione 350 g ha-1.

Genetic Divergence for Grain Yield and Its Components in Bread Wheat (Triticum aestivum L.): Experimental Investigation

The present investigation Comprises 34 advanced breeding lines including checks of bread wheat and experiment was conducted in a complete randomized block design with three replications at the research farm department of genetics and plant breeding, RVSKVV, B.M. College of Agriculture, Khandwa during Rabi season (November 2021 to April 2022) for estimation of the multivariate analysis of divergence. The advanced breeding lines were grouped into seven clusters. Cluster III contained the highest number of advanced breeding lines(12) and clusters V, VI, and VII contained the lowest (1 each). The inter-cluster distance in most cases was larger than the intra cluster distance which indicated that wider diversity is present among the advanced breeding lines of distant grouped. The highest intra cluster distance was observed in cluster IV revealed maximum genetic divergence among its constituents. The highest inter-cluster distance was found between cluster VI and VII and the lowest was between cluster V and VI. Highest cluster mean exhibited in cluster VII for most of the agro-morphological traits i.e. number of tillers/plant, spike length, spike weight, number of grain/spike followed by cluster II for grain filling period, days to maturity and plant height. On the basis of genetic diversity analysis, maximum percent contribution towards genetic divergence in 34 advanced breeding lines were found in grain filling period, days to maturity, number of grain/spike, days to 50% flowering, biological yield per plant and harvest index. Such differences in the genetic component of traits studied in the manuscript can be applied as a source of variation in other breeding programmes and crossing nurseries for wheat improvement.