Studies on integrated weed management in greengram (Vigna radiata L.)

Introduction

Pulses are an excellent source of protein, carbohydrates, dietary fiber, vitamins, minerals, and phytochemicals, making them a vital component of human nutrition, particularly in developing countries (USDA, 2020) [16] . The lysine-rich protein of pulses serves as a natural supplement to cereals, which are typically deficient in this essential amino acid (Anonymous, 2024) [4] . For centuries, pulses have also functioned as "biological fertilizer factories," enriching the soil through biological nitrogen fixation, addition of organic matter, and reduction in the dependence on synthetic fertilizers (Ahirwar et al., 2016) [1] . Their inclusion in cereal-based crop rotations improves soil fertility, breaks pest and disease cycles, and enhances sustainability in farming systems (Ghanshyam et al., 2010) [8] . Pulses contribute nearly 14% of the total protein in the average Indian diet and act as the principal source of dietary protein for resource-poor populations (GOI, 2021-22) [9] . With the recommended dietary allowance (RDA) for protein being 0.8 g/kg body weight for adults, increased pulse production is a critical step toward ensuring nutritional security (Ali et al., 2011) [2] . India is the world's largest producer, consumer, and importer of pulses, with Madhya Pradesh, Maharashtra, Rajasthan, Uttar Pradesh, and Karnataka being the leading pulse-producing states (Bahadur & Tiwari, 2014) [5] . The country cultivates a wide range of pulses, including chickpea, pigeon pea, mungbean, black gram, lentil, and kidney beans. Of these, chickpea and pigeon pea dominate, accounting for nearly 60% of total production (GOI, 2021-22) [9] . Pulses are cultivated in three distinct seasons: rabi (gram, lentil, pea, lathyrus, rajmash), kharif (pigeon pea, green gram, cowpea, horse gram), and summer (green gram, black gram, cowpea, horse gram). Notably, more than 60% of pulse production comes from rabi pulses (Kumari et al., 2015) [12] . Green gram (Vigna radiata L.), also called mungbean or golden gram, is the fourth most important pulse crop in India. It is cultivated mainly in arid and semi-arid regions and accounts for about 1.6% of the total pulse acreage (Gupta et al., 2016) [10] . Being a short-duration crop, it can be successfully grown on well-drained loamy to sandy loam soils and is often included as a catch crop between rabi and kharif seasons (Choudhary & Yadav, 2011) [7] . It is moderately tolerant of drought, grows 40-120 cm in height, and has trifoliate leaves with hairy surfaces. Its pods are usually 4-16 cm long, cylindrical to slightly curved, and contain small globular seeds that may be green, yellow, brown, or black speckled (Mohammad et al., 2017) [13] . Nutritionally, green gram is regarded as a high-quality pulse due to its superior digestibility and high protein content (20-28%). Its protein fraction is rich in lysine and tryptophan, often earning it the title "queen of pulses" (Amit et al., 2019) [3] . In addition, it contains 55-60% carbohydrates, 1.0-1.5% fat, 3.5-4.5% fiber, and 4.5-5.5% ash (USDA, 2020) [16] . Despite its nutritional and economic importance, the productivity of green gram is severely constrained by weed infestation. Weeds compete aggressively with the crop for nutrients, light, water, and space during the critical early growth stages, leading to yield reductions of 30-80% depending on the season and weed flora (Chaudhari et al., 2016; Singh, 1993) [6,14] . Studies have shown that weed-induced yield losses can reach as high as 85% in the absence of timely management (Singh et al., 2015) [15] . Thus, integrated weed management (IWM) strategies that combine cultural, mechanical, chemical, and biological measures are crucial for achieving sustainable production of green gram (Khan & Joergensen, 2019) [11] . In this context, the present investigation entitled "Study on Integrated Weed Management in Green Gram (Vigna radiata L.)" was conducted during the kharif season of 2024 at the Student's Instructional Farm, Rama University, Kanpur Nagar, with the following objectives: 1. To assess the effect of different weed control measures on the density and biomass production of weeds. 2. To evaluate the impact of weed management practices on the growth and yield of green gram. 3. To determine the economic feasibility of different weed control treatments. on the right bank of the holy Ganga River. The experimental plot had an even topography and good drainage facility. Kanpur has a tropical climate with warm, humid monsoons, reasonably hot summers, and mildly cold winters. This area typically experiences heavy rainfall from June to September Therefore, Pendimethalin 30 EC @ 1 kg ha -1 as PE + one hand weeding at 20 DAS revealed to be an effective treatment in terms of B: C ratio and net return.

Location of

Effect on density and dry matter of grassy weeds

The data present in table -1 revealed how various weed management techniques at 30 and 60 DAS affected the density of grassy weeds. The results showed that two hand weeding treatment had the lowest recorded weed density (3.7 and 4 m -2 ) was followed by Pendimethalin 30 EC @ 1 kg ha -1 as PE + one hand weeding (3.9 and 4.9 m -2 ), Pendimethalin 30 EC @ 1kg ha - 1 as PE + Imazethapyr 10 SL @ 100ml ha -1 as PoE (4.4 and 5.26 m-2). The highest weed density recorded in unweeded control treatment (8.9 and 10.84 m -2 ). Among the herbicide treatments, integrated weed management treatment like Pendimethalin 30 EC @ 1 kg ha -1 as PE + one hand weeding proved to be the most successful in reducing grass density as compared to application of pre or post emergence herbicides only.

Effect on dry matter of grasses

The data present in unambiguously show that, at 30 and 60 DAS, various weed management techniques had an impact on the dry matter of grassyweeds. Significantly, it was observed that the two hand weeding treatments recorded the lowest dry matter (2.21 and 2.33g m-2) and were succeeded by Pendimethalin 30 EC @ 1 kg ha -1 as PE + one hand weeding (2.29 and 3.2 g m-2), Pendimethalin 30 EC @ 1 kg ha -1 as PE + Imazethapyr 10 SL @ 100ml ha -1 as PoE (2.42 and 3.29 g m-2).

The maximum dry matter recorded in unweeded control treatment (5.61 and 7.37 g m-2). Among herbicide combinations, Pendimethalin 30 EC @ 1 kg ha -1 as PE + one manual weeding proved to be the most successful treatment for reducing the dry matter of grasses at 30 and 60 DAS.

Effect on density and dry matter of sedges

The data clearly show that, at 30 and 60 DAS, different weed management strategies had an impact on the density of sedges. Significantly, it was found that two hand weeding treatment had the lowest recorded weed density (2.56 and 2.84 m-2). This was followed by Pendimethalin 30 EC @ 1 kg ha -1 as PE + one hand weeding (2.79 and 2.86 m-2), Pendimethalin 30 EC @ 1 kg ha -1 as PE + Imazethapyr 10 SL @ 100ml ha-1 as PoE (3.45 and 3.12 m-2). The highest weed density recorded in unweeded control treatment (5.35 and 7.55 m-2). Among the herbicide treatments, integrated weed management treatment like Pendimethalin 30 EC @ 1 kg ha -1 as PE + one hand weeding proved to be the most successful in minimizing density of sedges as compared to application of pre or post emergence herbicides only.

Effect on dry matter of sedge

The data clearly showed that, at 30 and 60 DAS, different weed management strategies affect the dry matter of sedges. Significantly, it was observed that the two hand weeding treatments recorded the lowest dry matter (1.81 and 1.7g m-2) and were succeeded by Pendimethalin 30 EC @ 1 kg ha -1 as PE + one hand weeding (1.83 and 2 g m-2), Pendimethalin 30 EC @ 1 kg ha -1 as PE + Imazethapyr 10 SL @ 100ml ha

References

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