Weed Management through Combined Herbicides and its Influence on Soil fertility, Nutrient Content and Uptake of Summer Green gram (Vigna radiata L.)

Introduction

Green gram (Vigna radiata L.), commonly known as mung bean, is a short-duration, proteinrich pulse crop of considerable agronomic and nutritional importance in India. Being a legume, it enhances soil fertility through biological nitrogen fixation and plays a key role in sustainable cropping systems, particularly in rotations with cereals such as rice and wheat. India contributes over 70 per cent of the global production of green gram, making it the largest producer and consumer of this crop (Agricultural Market Intelligence Centre, PJTAU, 2025). At the national level, the area and production of green gram have increased in recent years. According to the 3 rd advance estimates of the Ministry of Agriculture and Farmers Welfare, the crop occupied about 35.27 lakh hectares in India during 2024-25, with an estimated production of 3.82 million tonnes (Agricultural Market Intelligence Centre, PJTAU, 2025). In Gujarat, green gram represents a smaller but growing component of the pulse sector. During 2024-25, the crop covered approximately 1.38 lakh hectares with a production of about 1.26 lakh tonnes, indicating gradual expansion and stable productivity (Gujarat Agriculture Department, 2026). The increasing area, production and yield of green gram highlight its growing importance in Indian agriculture. Understanding production trends and associated constraints is essential for improving productivity and strengthening diversified cropping systems. Among the major production constraints, weed competition is particularly severe during the early growth stages of green gram. Yield losses due to uncontrolled weeds have been reported to range from 65.4 to 79.0 per cent, depending on weed flora, intensity of infestation and duration of crop-weed competition (Dungarwal et al., 2003) [4] .

Weeds compete with crop plants for vital resources such as nutrients, moisture, light and space especially during the critical early growth period, leading to substantial yield reduction if not effectively controlled. In recent years, herbicide mixtures or combinations have been increasingly adopted for efficient weed management. Since a single herbicide often fails to control diverse weed species effectively, herbicide combinations broaden the spectrum of weed control by targeting both grassy and broad-leaved weeds while minimizing the risk of crop injury. Therefore, effective weed management during the critical period of crop-weed competition is essential to achieve higher productivity in green gram.

Materials and Methods

A field experiment was conducted during the summer season of 2018 at the College Farm, N. M. College of Agriculture, Navsari Agricultural University, Navsari, Gujarat. The experimental soil was clayey in texture with low, medium and high levels of available N, P₂O₅ and K₂O, respectively. The soil was slightly alkaline in reaction (pH 8.1) with normal electrical conductivity. Green gram variety 'Meha' was used as the test crop. Prior to sowing, seeds were treated with Ceresan at 3.0 g kg⁻¹ seed to prevent seedborne fungal diseases, followed by inoculation with Rhizobium culture to enhance biological N fixation. The treated seeds were shade-dried before sowing. Sowing was performed on 5 th February 2018 by the line sowing method with a spacing of 30 cm × 10 cm between rows and plants, respectively, using a seed rate of 20 kg ha⁻¹. A basal fertilizer dose of 20-40-00 NPK kg ha⁻¹ was applied at sowing through urea and single superphosphate (SSP), respectively, while no potassium fertilizer was applied. The herbicides evaluated in the study included pendimethalin; imazethapyr + pendimethalin (RM); imazethapyr + imazamox (RM); sodium acifluorfen + clodinafop-propargyl (RM); imazethapyr + propaquizafop (RM); quizalofop-p-ethyl; and fenoxaprop-p-ethyl. The required quantity of each herbicide was measured using a graduated cylinder according to the treatment specifications. Herbicide application was performed using a knapsack sprayer fitted with a flat-fan nozzle, delivering a spray volume of 500 L ha⁻¹ to ensure uniform coverage. Pendimethalin, imazethapyr + pendimethalin (RM), and imazethapyr + imazamox (RM) were applied as preemergence (PE) treatments, whereas sodium acifluorfen + clodinafop-propargyl (RM), imazethapyr + propaquizafop (RM), quizalofop-p-ethyl, and fenoxaprop-p-ethyl were applied as post-emergence (PoE) treatments. Pre-emergence herbicides were applied two days after sowing, following irrigation. The quantity of commercial formulation required for each treatment was calculated based on the active ingredient concentration using the following formula:

Where, Rh =Required quantity of trade formulation of herbicide (ha⁻¹), Ai = Quantity of active ingredient to be applied (kg), At = Area to be treated (ha), and Ci = Concentration of active ingredient (%) in the commercial formulation. Total uptake of N, P 2 O 5 and K 2 O by crop and weeds was calculated by using the following formula.

𝑁𝑢𝑡𝑟𝑖𝑒𝑛𝑡 𝑢𝑝𝑡𝑎𝑘𝑒 (𝑘𝑔 ℎ𝑎 -1) = 𝑁𝑢𝑡𝑟𝑖𝑒𝑛𝑡𝑐𝑜𝑛𝑡𝑒𝑛𝑡 𝑖𝑛 𝑐𝑟𝑜𝑝 𝑜𝑟 𝑤𝑒𝑒𝑑𝑠 (%) × 𝐶𝑟𝑜𝑝 𝑦𝑖𝑒𝑙𝑑 𝑜𝑟 𝑑𝑟𝑦 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑤𝑒𝑒𝑑 (𝑘𝑔 ℎ𝑎 -1) 100 [5,6] .

Results and Discussion

Nutrient Uptake by Seed and Straw

The results presented in Table 3 showed that weed management practices significantly influenced the uptake of N, P₂O₅ and K₂O by seed and straw of green gram. The highest uptake of N (48.9 and 19.4 kg ha⁻¹), P₂O₅ (6.2 and 4.3 kg ha⁻¹) and K₂O (27.9 and 18.1 kg ha⁻¹) by seed and straw, respectively, was recorded under the weed-free treatment (T₁₀), which was statistically at par with T₈.

The lowest uptake of N (21.3 and 5.9 kg ha⁻¹), P₂O₅ (2.2 and 1.3 kg ha⁻¹) and K₂O (8.4 and 5.2 kg ha⁻¹) by seed and straw, respectively, was recorded under the unweeded control (T₉).

Total Nutrient Uptake by Crop

Total uptake of N, P₂O₅ and K₂O by green gram crop was significantly influenced by different weed management treatments. The highest total uptake of N, P₂O₅ and K₂O (68.3, 10.5 and 45.9 kg ha⁻¹, respectively) was recorded under the weed-free treatment (T₁₀), which remained statistically at par with T₈ (60.0, 8.8 and 39.4 kg ha⁻¹, respectively). The lowest total uptake of N, P₂O₅ and K₂O (27.2, 3.5 and 13.6 kg ha⁻¹, respectively) was observed under the unweeded control (T₉).

The higher content and uptake of nutrients by seed and straw due to lesser crop weed competition, resulted in better development of crop growth. Further, the higher nutrients content in seed and straw and more biomass production under these treatments boosted the nutrient uptake by the crop. The finding for the nutrient uptake was followed the pattern of those were reported by Chhodavadia et [2. 3, 6, 7, 8, 12] in green gram. [2,3,6,13] .

Conclusion

Field experimentation indicated that post-emergence application of sodium acifluorfen + clodinafop-propargyl (RM) @ 250 g ha⁻¹ at 20 DAS proved most effective for yield, profitability, and weed control in summer green gram. Manual weeding (weed-free or two hand weedings at 20 and 40 DAS) was equally effective when labour was available. Weed-free treatment (T₁₀) recorded maximum yield, nutrient uptake, and soil fertility, while unweeded control (T₉)

showed the lowest performance. Overall, effective weed management reduced nutrient competition and improved productivity and soil health.

References

1. Agricultural Market Intelligence Centre, PJTAU. Green gram outlook -October 2025 (3rd advance estimates). Ludhiana: Punjab Agricultural University; 2025. Available from: https://www.pjtau.edu.in/files/AgriMkt/2025/October/G reen%20gram-October-2025.pdf
2. Chhodavadia SK, Mathukiya RK, Dobariya VK. Preand post-emergence herbicides for integrated weed management in summer green gram. Indian J Weed Sci. 2013;45(2):137-139.
3. Choudhary VK, Suresh KP, Bhagawati R. Integrated weed management in black gram (Vigna mungo) under mid hills of Arunachal Pradesh. Indian J Weed Sci. 2012;57:382-385.
4. Dungarwal HS, Chaplot PC, Nagda BL. Effect of weed management practices on weed dynamics and yield of mung bean (Vigna radiata L.). Indian J Weed Sci. 2003;35(3-4):283-285.
5. Ganapathi S, Dhanapal GN, Bai Kamala S, Ajmal KK. Tillage and weed management on yield and nutrient uptake of green gram under maize-green gram cropping system in conservation agriculture. Indian J Agric Res. 2024;58(6):1158-1167. doi:10.18805/IJARe.A-6299.
6. Kumar P, Patel JN, Alam MS. Effect of weed management practices on nutrient content and their uptake by green gram (Vigna radiata L.). J Exp Agric Int. 2024;46(7):1144-1152. doi:10.9734/jeai/2024/v46i72667.
7. Kumar RS, Angiras NN, Singh R. Studies of planting and weed control methods on nutrient uptake by black gram (Vigna mungo) under mid hill conditions of Himachal Pradesh. Himachal J Agric Res. 2007;33:710.
8. Modak R, Chakraborty T, De GC. Method of weed management on weed biomass, yield and nitrogen uptake of black gram (Phaseolus mungo). Indian J Agron. 1995;40:115-117.
9. Patel YB, Hatti V, Patel JK, Patel DM, Singh AK, Kumar V. Weed management practices influence productivity and profitability in kharif green gram (Vigna radiata L.). Int J Res Agron. 2024;7(10):678683.
10. Production of pulses in Gujarat doubles in six years: Govt. Times of India. 2026 Jan. Available from: https://timesofindia.indiatimes.com/city/ahmedabad/pro duction-of-pulses-in-gujarat-doubles-in-six-yearsgovt/articleshow/126359650.cms
11. Pulses production doubles in Gujarat in six years. iGrain. 2026 Jan 7. Available from: https://igrain.in/posts/pulses-production-doubles-ingujarat-in-six-years
12. Singh K, Singh SP, Yadav RS. Effect of weed management on growth, yield and nutrient uptake of kharif mung bean. Indian J Weed Sci. 2015;47(2):206210.
13. Vivek NS, Singh RR, Tomar SS. Effect of weed interference on weeds and productivity of black gram (Phaseolus mungo). Indian J Weed Sci. 2008;40(12):65-67