Response of weed management practices in the field of wheat (Triticum aestivum) crops

Introduction

As per Second Advance Estimates for the agriculture year 2022-23, the Wheat production in the country is estimated at 112.18 million tons which is higher by 4.44 million tons than the production achieved during 2021-22. The Wheat Market size is forecast to increase by USD 73.16 billion, at a CAGR of 4.54% between 2023 and 2028. The market is influenced by several key factors, including the expanding vegan population, the rising adoption of healthy eating habits, cultured wheat and the increasing global production of wheatbased items. It is the second largest producer of rice, wheat, cotton, sugarcane, farmed fish, sheep & goat meat, fruit, vegetables and tea. The country has some 195 m ha under cultivation of which some 63 percent are raifed (roughly 125m ha) while 37 percent are irrigated (70m ha). India's wheat production is projected to reach 111.32 million tons in 2023-24, up from 109.52 million tons in 2022-23, reflecting a compound annual growth rate (CAGR) of 1.64%. Soil degradation, water scarcity, and declining farm profitability further exacerbate the sustainability concerns associated with wheat cultivation by AllIndiaWheatSurveyReport2023-2024. In agriculture weed causes more damage compared to insects, pests and diseases but due to hidden loss by weed in crop production, it has not drawn much attention of agriculturists (Rao, 2001) [1] . Weeding at an early stage of crop growth in wheat is a very important practice because heavy infestation of weeds hampers the crop growth as well as greater reduction in wheat yield. Slow growth of wheat plants during the early growth stage provides specific conditions for the growth of various weed flora at the time of germination and also subsequent growth periods. Herbicides on account of their selectivity are the most important tools in weed management to sustain yield and quality of crop (Mitra et al., 2019) [2] . The prominent weeds noted in wheat field are Phalaris minor, Cyperus rotundus, Cynodon dactylon, Chenopodium album, Anagallis arvensis, Avena fatua, Convolvulus arvensis and Lathyrus spp. etc., which alone causes 33 percent reduction in wheat yield, Rice-Wheat is one of the most important cropping systems in the northern part of the country stretches from Jammu plains to lower Assam having an area about 10.8 m ha. The cultivators are not aware of proper dose of herbicides, time of application, economics and their persistence in the soil. Several selective herbicides are available in the market, which are treated to be effective for particular crops. The farmers have to make decisions about the selection of the right type of herbicides.

Materials and Methods

The particulars of experimental material used and techniques adopted during the course of investigation entitled "Bio-efficacy of new herbicide (prosulfocarb) against weeds specially phalaris minor in wheat crop (Triticum aestivum L.)" are described in this chapter. Field experiment was carried out during rabi season of 2021-22 at Agriculture Research Farm Rama University, Mandhana Kanpur (U.P). The treatments were laid out in Randomized Block Design (RBD) being weedmanagement practices (8) with three replications and the basic principles of randomization were followed. In order to determine the physio-chemical characteristics of the soil and fertility status, the soil samples were collected at random from 10 places of the experimental field with the help of soil auger to a depth at 0-15 cm. The collected soil samples were mixed together and a composite sample was drawn and analyzed in the laboratory for physio chemical properties.

Result and Discussion

Initial plant population

The data pertaining to initial plant population was recorded at 15 DAS and Plant height presented in Table .1. It clearly reveals that different weed control treatments did not influence significantly. At 30 days' stage, weed free up to 25-50 days recorded the non-significantly tallest plant followed by post-emergence spray of Clodinopop + Metsulfuron @ 60g+4g a.i./ha (POE). Among the postemergence herbicide, application of sulfosulfuron + metsulfuron @ (60+4) recorded slightly higher plant height (24.10 cm) followed by Clodinopop + Metsulfuron @ 60g+4g a.i./ha (POE) 23.77 cm. The data recorded highest under the treatment sulfosulfuron + metsulfuron @ (60+4) are 24.10 followed by Clodinopop + Metsulfuron @ 60g+4ga.i./ha (POE) 23.77. The herbicide treatment application of sulfosulfuron + metsulfuron @ (60+4) recorded significantly more plant height 24.1 cm and 81.35 cm over prosulfocarb at the rate of 2000 ml & prosulfocarb 1600 ml at 30 days and 90 days. Among the prosulfocarb treatment pre-emergence spray of prosulfocarb 2000 ml/ha recorded non-significantly more height followed by prosulfocarb 3000 ml/ha. A similar higher value of crop growth was recorded by Pandey et al. (2007) [3] , Meena et al. (2011) [4] . Dry matter accumulation: Data regarding the effect of various weed management methods on dry matter accumulation in wheat is presented in the table. 2. Across all treatments, dry matter accumulation increased continuously from 30 DAS to 90 DAS. At 30 DAS, dry matter accumulation ranged from 1.85 to 2.62 g m⁻², with the highest value (2.62 g m⁻²) recorded in the weed-free treatment. Among the herbicidal treatments, the highest dry matter accumulation (2.43 g m⁻²) was recorded with postemergence (POE) application of sulfosulfuron + metsulfuron (30 + 4 g a.i. ha -1

), followed by clodinafop + metsulfuron (60 + 4 g a.i. ha -1 ) (2.36 g m -2 ). The lowest dry matter accumulation was observed in the weedy check (1.85 g m -2 ). However, the differences between treatments at 30 DAS were not significant, as indicated by the nonsignificant (NS) CD (P = 0.05) value. At 90 DAS, dry matter accumulation increased substantially, ranging from 15.17 to 22.17 g m -2 . The highest dry matter accumulation was recorded in the weed-free treatment (22.17 g m -2

), followed by sulfosulfuron + metsulfuron (20.55 g m -2 ) and clodinafop + metsulfuron (19.94 g m -2

). Applications of prosulfocarb 80 EC at rates of 1600, 2000, and 3000 ml a.i. ha -1 resulted in dry matter accumulation of 17.35, 17.98, and 18.33 g m -2 , respectively. The lowest value was recorded in the weed-infested check (15.17 g m -2 ). A CD (P = 0.05) value of 1.40 g m -2 indicated that the treatments significantly influenced dry matter accumulation at 90 DAS. The higher dry matter accumulation observed in weed-free and effective herbicide treatments can be attributed to reduced weed competition for light, moisture, nutrients, and space, leading to enhanced crop growth and biomass production. Conversely, where weeds were not removed, their continued presence stunted crop growth and resulted in lower dry matter accumulation. Similar findings regarding improved crop growth and dry matter production through effective weed management in wheat have been reported by Chopra et al. (2008) [5] and Mahajan et al. (2012) [6] . The present results also align with the general consensus that early removal of weeds during the critical period of crop-weed competition alleviates competition, thereby resulting in greater biomass accumulation. Similarly, efficient control of weed. Lower crop weed competition to crop and higher availability of plant nutrient to crop under herbicide applied in combination resulted in higher plant growth in terms of dry matter accumulation as compared to herbicide applied alone which having poor efficiency to control weed resulted in lower growth attributes. Higher crop weed competition due to higher weed population and dry weight of weed resulted in poor availability of nutrients to crop causing poor dry matter accumulation. A similar higher value of dry matter accumulation of crops was recorded by Pal et al. (2012).

Conclusion

The results of experiments conducted at Agronomy research farm Rama University Mandhana Kanpur (U.P.) during 2021-22 conducted that to ensure maximum grain yield and remuneration from wheat. Weed free found no-significant at the stage of initial plant population and 30 DAS, but latter stage of the growth of plant at the stage of 90 DAS among the treatment Sulfosulfuron + Metsulfuron (30 + 2 g ha -1 ) (81.35 cm) found significant effect on crop growth followed by clodinafop + Metsulfuron (60+4) g/ha (78.91) at 90 DAS stage. Highest plant heights were recorded under the weed free plot while minimum plant height under weedy check treatment. Weed free found most effective to dry matter accumulation. Among the herbicide post emergence application of Sulfosulfuron + Metsulfuron (30+4) gm.a.i./ha which was found to be the most effective weed control.

References

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