Effect of post emergent herbicides and foliar nutrition on weed control, productivity and quality of greengram

Introduction

Greengram (Vigna radiata L.) is one of the most important pulse crops grown in India because of its high nutritional value, short duration and ability to enrich the soil fertility through biological nitrogen fixation. It is an excellent source of protein (about 24%), carbohydrates, vitamins and essential minerals, making it an important component of balance human diet. In India, greengram occupies an area of 5.624 mha with a production of 2.069 mt and average productivity of 368 kg ha -1 (2025-26). In karnataka, it is grown over an area of 4.18 lakh ha with a production of 1.52 lakh tonnes and productivity of 364 kg ha -1 (2025-26). (DAC&FW, GoI, UPAg 2025-26). Weed infestation during the early growth period is one of the major factor limiting the greengram productivity. Weeds compete aggressively with the crop for moisture, nutrients, light and space resulting in the yield losses of 40-60 per cent. Although manual weeding is effective, but nowadays labour are becoming increasingly scare and expensive. Therefore, post-emergence herbicides act as an a economically alternative approach for broad-spectrum weed control thereby improving crop growth and productivity Basal fertilizer application alone may not be sufficient to meet the crop nutrient demand during flowering and pod development, often leads to flower drop, poor pod setting and reduced yield. Foliar nutrition at critical growth stages enhances nutrient use efficiency, maintains photosynthetic activity, improves nutrient uptake and ultimately contributes to better growth, yield and grain quality. Therefore, integrating effective post-emergence herbicides with suitable foliar nutrition offers a promising strategy to enhance the weed control, nutrient uptake, productivity and quality of greengram.

Materials and Methods

The field experiment entitled "Effect of Post-emergence Herbicides and Foliar Nutrition on Weed Control, Productivity and Quality of Greengram" was conducted during Kharif 2025 at the College of Agriculture, Navile, Shivamogga, Karnataka. The experiment was laid out in a Factorial Randomized Complete Block Design (FRCBD) with 12 treatment combinations comprising of four weed management practices and three foliar nutrition treatments, which is replicated three times. The weed management treatments include, Weedy check (W 1 ), Weed free (W 2 )., Propaquizafop 2.50% + Imazethapyr 3.75% @ 125 g ha -1 (W 3 ). and Fomesafen 11.1% + Fluazifop-p-butyl 11.1% @ 220 g ha -1 (W 4 )., were applied at 20 DAS, and foliar nutrition treatments consisting of DAP 2% (F 1 ), Pulse Booster 1% (F 2 ) and Pulse Magic 1% (F 3 ) were sprayed 10 days after flowering. Standard agronomic practices were followed throughout the crop growth period. Observations on weed parameters, growth, yield attributes, yield, and quality were recorded. The experimental data obtained were analysed using analysis by the analysis of variance (ANOVA) for Factorial RCBD as described by Gomez and Gomez (1984) [5] .

Results and Discussion

The experimental field was infested with a mixed weed flora, broad-leaved weeds like (Trianthema portulacastrum, Parthenium hysterophorus, Commelina benghalensis and Portulaca oleracea), grasses (Digitaria spp. and Cynodon dactylon) and sedges (Cyperus rotundus and Cyperus esculentus), A similar weed flora has also been reported in greengram (Dungarwal et al., 2003) [4] . Weed density at 35 DAS significantly influenced by weed management practices (Table 1). The weedfree treatment (W 2 ) recorded the lowest density (0.71 weeds m -2 ), whereas the weedy check (W 1 ) recorded the highest (7.57 broadleaved weeds, 7.82 grasses and 7.31 sedges m -2 ). Among the herbicidal treatment, Propaquizafop 2.50% + Imazethapyr 3.75% @ 125 g ha⁻¹ (W 3 ) recorded significantly lower density of broad -leaved weeds, grasses and sedges (2.48, 2.25 and 2.00 m -2 , respectively) than Fomesafen 11.1% + Fluazifop-p-butyl 11.1% @ 220 g ha -1 (W 4 ) (3.36, 3.88 and 3.60 m -2 ). This might be attributed due to the complementary mode of action of propaquizafop and imazethapyr, while propaquizafop effectively control the grassy weeds through ACCase inhibition, Imazethapyr supresses broad-leaved weeds and sedges by inhibiting the ALS enzyme, resulting in broad spectrum weed control (Khairnar et al., 2014) [7] . While foliar nutrition and its interaction with weed management had no significant effect, since spraying was done at 10 days after flowering. Weed management practices significantly influenced both weed control efficiency (WCE) and weed index (WI) (Table 2). The weed-free treatment (W 2 ) recorded 100% WCE along with the lowest weed index (2.99%), whereas the weedy check (W 1 ) registered the lowest WCE (7.49%) and the highest weed index (59.79%). Among the herbicidal treatments, Propaquizafop 2.50% + Imazethapyr 3.75% @ 125 g ha -1 (W 3 ) proved more effective than Fomesafen 11.1% + Fluazifop-p-butyl 11.1% @ 220 g ha -1 (W 4 ) by recording significantly higher WCE (87.58%) and a lower weed index (4.88%), compared with 84.43% and 6.38%, respectively (Table 2). This improved performance may be attributed due to rapid foliar uptake and residual activity of the herbicide combination, which provided sustained weed suppression during the crop's critical growth period (Suryavanshi et al., 2018) [13] . Among the foliar nutrition treatments, Pulse Magic @ 1% (F 3 ) recorded the highest WCE (72.22%) and the lowest weed index (15.00%). Although foliar nutrition does not directly control weeds, improved crop nutrition likely enhanced crop vigour, improved nitrogen and phosphorous uptake balanced supply of macro and micronutrients along with plant growth regulator resulted in reduced weed index. (Al-Ziady et al., 2021) [2] . The interaction between weed management and foliar nutrition was non-significant for WCE but significant for weed index. Among the herbicidal combinations, W 3 F 3 recorded the lowest weed index, whereas W 1 F 1 recorded the highest (63.78%). The lower weed index under W 3 F 3 can be attributed to the effective suppression of weeds by the post-emergence application of Propaquizafop + Imazethapyr at 20 DAS, which reduced cropweed competition during the early growth stages. The subsequent application of Pulse Magic @ 1% at 10 days after flowering further improved crop growth by supplying phosphorus, potassium, micronutrients and growth-promoting substances during the reproductive stage, when nutrient demand is high. This combination enabled the crop to utilize available resources more efficiently, resulting in higher seed yield and a weed index comparable to the weed-free treatment (Rajarathinam et al., 2025) [9] . Weed management practices significantly influenced pods per plant, pod length, seeds per pod and 100-seed weight (Table 4). The weed-free treatment (W 2 ) recorded the highest values for pods per plant (27.07), pod length (10.00 cm), seeds per pod (11.38) and 100-seed weight (6.34 g), which is statistically on par with W 3 (26.31, 9.81 cm, 11.01 and 6.08 g, respectively). Both treatments were significantly superior to W 4 and W 1 . This improvement might be attributed due to reduced crop-weed competition during the reproductive stage, resulting in better flower retention, pod set and improved source-sink relationships (Ali et al., 2013) [1] . Among the foliar nutrition treatments, Pulse Magic @ 1% (F 3 ) recorded significantly higher values for all yield attributes, including pods per plant (24.46), pod length (9.71 cm), seeds per pod (11.08) and 100-seed weight (5.79 g), followed by Pulse Booster @ 1% (F 2 ) and DAP @ 2% (F 1 ). The improvement under Pulse Magic may be due to an adequate supply of phosphorus during flowering, which enhanced pollen viability and fertilization, thereby improving pod and seed development (Venkatesh and Basu, 2011) [15] . The interaction effect was significant for pods per plant, pod length and seeds per pod. The combination W₂F₃ recorded the highest values and remained statistically on par with W 3 F 3 . This response might be attributed to the combined effect of effective weed control and timely foliar nutrition, which improved assimilate partitioning towards pod and seed development (Rajarathinam et al., 2025) [9] . Weed management practices significantly influenced seed yield and haulm yield (Table 5). The weed-free treatment (W 2 ) recorded the highest seed yield (1340 kg ha -1 ), haulm yield (1553 kg ha -1) and protein content (22.56%), and which is statistically on par with W 3 (1314 and 1550 kg ha -1 ; 21.31%, respectively). Both treatments were significantly superior to W 4 and W 1 , with the weedy check recording nearly 59% lower seed yield. The higher productivity under W 2 and W 3 may be attributed to effective weed control, which reduced competition for moisture, nutrients and light, resulting in better translocation of photosynthates to developing pods and seeds. Improved nitrogen availability under reduced weed competition also contributed to higher seed protein content (Verma and Kushwaha, 2019) [16] . Among the foliar nutrition treatments, Pulse Magic @ 1% (F 3 ) recorded significantly higher seed yield (1174 kg ha -1 ) and haulm yield (1412 kg ha -1 ) than DAP @ 2% (F 1 ). The improvement may be due to rapid absorption of foliarapplied nutrients and their efficient translocation to developing pods. The balanced supply of macro and micronutrients, together with phosphorus and plant growth regulators in Pulse Magic, enhanced pod filling, seed development and protein synthesis (Venkatesh and Basu, 2011) [15] . The interaction effect was significant for seed and haulm yield, with W 2 F 3 recording the highest values (1382 and 1583 kg ha -1 ), followed closely by W 3 F 3 (1337.66 and 1560.33 kg ha -1 ), while W 1 F 1 recorded the lowest yields (500 and 804 kg ha -1 ). The higher yield under W 2 F 3 and W 3 F 3 may be attributed to the combined effect of effective weed suppression and balanced foliar nutrition, which improved source-sink relationships and seed filling (Al-Ziady et al., 2021) [2] . Among the weed management practices, the weed-free treatment (W 2 ) recorded the highest gross returns (₹95,368 ha -1 ). However, W 3 , recorded the highest net returns (₹57,538 ha -1 ) and B:C ratio (2.60), followed by W 4 (₹55,701 ha -1 and 2.53), while the lowest returns were recorded under W 1 (₹4,524 ha -1 and 1.13) (Table 6). The higher profitability of W 3 might be attributed to lower labour and cultivation costs associated with a single herbicide application, while maintaining yields comparable to the weedfree treatment (Rajarathinam et al., 2025) [9] . Among the foliar nutrition treatments, Pulse Magic @ 1% (F 3 ) recorded the highest net returns (₹44,557 ha -1 ) and B: C ratio (2.14), compared with DAP @ 2% (F 1 ) (₹38,940 ha -1 and 2.02, respectively). This may be due to the greater yield response obtained with Pulse Magic, resulting in improved economic efficiency (Muthal et al., 2016) [8] . The interaction effect was significant, with W 3 F 3 recording the highest net returns (₹58,896 ha -1 ) and B: C ratio (2.62) among all treatment combinations. This could be attributed to the combined advantage of an effective, low-cost herbicide and balanced foliar nutrition, which maximized yield while minimizing production costs (Rajarathinam et al., 2025) [9] .

Conclusion

The present study demonstrated that application of Propaquizafop 2.50% + Imazethapyr 3.75% @ 125 g ha -1 at 20 DAS followed by Pulse Magic @ 1% applied 10 days after flowering (W 3 F 3 ) significantly improved growth, yield attributes, seed yield, haulm yield and benefit: cost ratio compared with the weedy check. Although the weed-free treatment combined with Pulse Magic (W 2 F 3 ) recorded the highest seed and haulm yields, it remained statistically on par with W 3 F 3 , which recorded the highest net returns and B: C ratio among all treatment combinations. Therefore, Propaquizafop 2.50% + Imazethapyr 3.75% @ 125 g ha -1 at 20 DAS followed by Pulse Magic @ 1% sprayed 10 days after flowering can be recommended as an effective, economical and labour-saving weed management strategy for enhancing the productivity and profitability of rainfed greengram.

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