Effect of different weed management practices on weed density, weed dry matter and weed control efficiency in maize (Zea mays L.)

Introduction

Maize (Zea mays L.) is one of the world's most important cereal crops owing to its high yield potential, wide adaptability, and multiple uses as food, feed, and industrial raw material. In India, maize is cultivated under diverse agro-climatic conditions and plays a significant role in ensuring food and nutritional security. However, its productivity is often constrained by several biotic and abiotic factors, among which weed infestation is one of the most serious limitations. The slow initial growth and wider row spacing of maize favour rapid weed emergence and establishment, resulting in severe competition for nutrients, moisture, light, and space. Uncontrolled weed growth during the critical period of crop-weed competition (15-45 days after sowing) may cause grain yield losses ranging from 30 to 80%, depending on weed species, density, and environmental conditions. Therefore, timely and effective weed management is essential for reducing crop-weed competition and improving crop productivity. Maize fields are generally infested with a mixed weed flora consisting of grasses, broadleaved weeds, and sedges. The composition and intensity of weed infestation vary with agroclimatic conditions, soil type, and crop management practices. Weed density and weed dry matter accumulation are widely used to assess the severity of weed infestation, while Weed Control Efficiency (WCE) is an important indicator of the effectiveness of different weed management practices. These parameters provide valuable information for comparing the bio-efficacy of herbicides and identifying suitable weed management strategies.

Although manual weeding is effective, its adoption has become increasingly difficult because of labour scarcity and rising production costs. Consequently, post-emergence herbicides have emerged as an efficient and economical alternative for controlling complex weed flora in maize. Herbicides such as mesotrione, Mesotrione + Atrazine, topramezone, halosulfuron-methyl, and nicosulfuron have shown promising results against mixed weed populations under different agro-ecological conditions. However, their effectiveness varies depending on weed composition, environmental conditions, and application timing. Therefore, the present investigation was undertaken to evaluate the influence of different weed management practices on weed density, weed dry matter accumulation, and weed control efficiency in maize under the agroclimatic conditions of Bilaspur, Chhattisgarh Akhtar et al. (2017) [1] .

Materials and Methods

Experimental site and location

The field investigation was carried out during the kharif 2025 season at the Instructional-cum-Research Farm of Barrister Thakur Chhedilal College of Agriculture and Research Station, Bilaspur, Chhattisgarh, India. The experimental farm is located at 22°09′ N latitude and 82°15′ E longitude, with an elevation of approximately 264 m above mean sea level. The study area falls under the subhumid tropical climatic zone, characterized by hot summers and moderate rainfall, with the majority of precipitation occurring during the southwest monsoon period from June to September. The experiment was laid out in a Randomized Block Design (RBD) with three replications comprising seven weed management treatments. Maize (Zea mays L.) was sown at the recommended row spacing of 60 cm using recommended agronomic practices. Fertilizer was applied as per the recommended dose, and all intercultural operations, except weed management, were carried out uniformly in all treatments.

Treatments details

The experiment was laid out in a Randomized Block Design (RBD) with Seven treatments and three replications. Treatments are: T₁: untreated control (weedy check), T₂: hand weeding at 30, 45 and 60 Days After Sowing (DAS), T₃: Topramezone 33.6% SC @ 25.2 g a.i. ha⁻¹ applied as post-emergence at 30 DAS, T₄: Mesotrione 2.27% + Atrazine 22.7% SC @ 80 + 795 g a.i. ha⁻¹ applied as postemergence at 30 DAS, T₅: Mesotrione 40% SC @ 80 g a.i. ha⁻¹ applied as post-emergence at 30 DAS, T₆: Halosulfuron-methyl 75% WG @ 67.5 g a.i. ha⁻¹ applied as post-emergence at 30 DAS, and T₇: Nicosulfuron 75% WDG @ 45 g a.i. ha⁻¹ applied as post-emergence at 30 DAS.

Statistical analysis

The data generated from the experiment were statistically analysed using Analysis of Variance (ANOVA) for a Randomized Block Design (RBD) following the procedure outlined by Gomez and Gomez (1984) [11] . The significance of differences among treatments was assessed using the Ftest at the 5% level of significance. Whenever the treatment effects were significant, the treatment means were separated using the Critical Difference (CD) test at the 5% probability level. [7] .

The weed management treatments did not significantly influence the density of grasses, broad-leaved weeds, sedges, or total weeds at 30 DAS. This could be attributed to the application of post-emergence herbicides after observation.

The weed management practices significantly influenced the density of grasses, broad-leaved weeds, sedges, and total weeds at 45 DAS. The untreated (T 1 ) recorded the highest weed density owing to the absence of any weed control measure. In contrast, hand weeding (T 2 ) at 30, 45 and 60 DAS proved to be the most effective treatment in minimizing weed density. Among the herbicidal treatments, post-emergence application of Mesotrione 2.27% + Atrazine 22.7% SC (T 4 ) was the most effective in suppressing the mixed weed flora, followed by Topramezone 33.6% SC (T 3 ). Comparatively higher weed density was observed under Mesotrione 40% SC (T 5 ), Halosulfuron-methyl 75% WG (T 6 ), and Nicosulfuron 75% WDG(T 7 ). The effective suppression of grasses, broad-leaved weeds, and sedges by hand weeding (T 2 ) and the Mesotrione + Atrazine (T4) combination resulted in lower weed infestation during the critical period of crop growth. These finding are agreement with Sandhya Rani et al. (2021) [9] .

The weed management treatments significantly influenced weed density at 60 DAS. The untreated (weedy check) (T₁) maintained the highest weed density throughout the observation period, indicating severe weed infestation in the absence of any weed control measure. Hand weeding at 30, 45 and 60 DAS (T₂) proved to be the most effective treatment in reducing weed density. Among the herbicidal treatments, Mesotrione 2.27% + Atrazine 22.7% SC @ 80 + 795 g a.i. ha⁻¹ applied at 30 DAS (T₄) recorded the lowest weed density, followed by Topramezone 33.6% SC @ 25.2 g a.i. ha⁻¹ applied at 30 DAS (T₃). The treatments Mesotrione 40% SC @ 80 g a.i. ha⁻¹ (T₅), Halosulfuronmethyl 75% WG @ 67.5 g a.i. ha⁻¹ (T₆), and Nicosulfuron 75% WDG @ 45 g a.i. ha⁻¹ (T₇) were comparatively less effective in suppressing the mixed weed flora. The sustained reduction in weed density under T₂ and T₄ indicated their superior effectiveness in controlling grasses, broad-leaved weeds, and sedges through (m -2 ) out the crop growth period. Similar finding reported by Mastkar et al. (2022) [4] .

The trend observed at harvest was similar to that recorded at the earlier stages of crop growth. The untreated (weedy check) (T₁) recorded the highest weed density, indicating continuous weed infestation throughout the crop season in the absence of any weed control measure. In contrast, hand weeding at 30, 45 and 60 DAS (T₂) maintained the lowest weed density. Among the herbicidal treatments, Mesotrione 2.27% + Atrazine 22.7% SC @ 80 + 795 g a.i. ha⁻¹ applied at 30 DAS (T₄) remained the most effective in reducing weed density, followed by Topramezone 33.6% SC @ 25.2 g a.i. ha⁻¹ applied at 30 DAS (T₃). The lower weed density observed under T₂ and T₄ reflected their sustained weed suppressive effect throughout the crop growth period, resulting in reduced crop-weed competition in maize. Similar finding reported by Chaudhari et al. (2023) [2] .

3.3

Weed dry matter (g m -2 ) 3.3.1 Weed dry matter (g m -2 ) at 30 DAS Weed management treatments did not significantly affect weed dry matter at 30 DAS. Since the post-emergence herbicides were applied after observation resulting in statistically similar weed dry matter across all treatments.

Weed dry matter (g m -2

) at 45 DAS Weed management practices significantly influenced weed dry matter at 45 DAS. The untreated (weedy check) (T₁) recorded the highest weed dry matter, whereas hand weeding at 30, 45 and 60 DAS (T₂) was the most effective treatment. Among the herbicidal treatments, Mesotrione 2.27% + Atrazine 22.7% SC (T₄) recorded the lowest weed dry matter, followed by Topramezone 33.6% SC (T₃). The lower weed dry matter under T₂ and T₄ indicated their effective weed suppressive ability during the crop growth period. Similar finding reported by Roy et al. (2023) [8] .

3.3.3

Weed dry matter (g m -2 ) at 60 DAS Weed management practices significantly reduced weed dry matter at 60 DAS. The untreated (weedy check) (T₁) recorded the highest weed dry matter, while hand weeding at 30, 45 and 60 DAS (T₂) was the most effective treatment. Among the herbicides, Mesotrione 2.27% + Atrazine 22.7% SC (T₄) recorded the lowest weed dry matter, followed by Topramezone 33.6% SC (T₃). The lower weed dry matter under T₂ and T₄ indicated their superior weed suppressive effect throughout the crop growth period. Similar finding reported by Mastkar et al. (2022) [4] .

Weed management practices significantly influenced weed dry matter at harvest. The untreated (weedy check) (T₁) recorded the highest weed dry matter, whereas hand weeding at 30, 45 and 60 DAS (T₂) recorded the lowest weed dry matter. Among the herbicidal treatments, Mesotrione 2.27% + Atrazine 22.7% SC (T₄) was the most effective, followed by Topramezone 33.6% SC (T₃). The lower weed dry matter under T₂ and T₄ reflected their sustained weed suppressive effect throughout the crop growth period. Similar finding reported by Kaul et al.

Weed control efficiency

The weed management treatments markedly influenced Weed Control Efficiency (WCE) during the crop growth period. No weed control efficiency was observed at 30 DAS, as the post-emergence herbicides were applied on the same day of observation. At 45 DAS, 60 DAS, and harvest, the untreated (weedy check) (T₁) recorded the lowest weed control efficiency due to the absence of any weed control measure. Hand weeding at 30, 45 and 60 DAS (T₂) consistently recorded the highest weed control efficiency throughout the observation period. Among the herbicidal treatments, Mesotrione 2.27% + Atrazine 22.7% SC @ 80 + 795 g a.i. ha⁻¹ applied at 30 DAS (T₄) exhibited the highest weed control efficiency, followed by Topramezone 33.6% SC @ 25.2 g a.i. ha⁻¹ (T₃). In contrast, Mesotrione 40% SC (T₅), Halosulfuron-methyl 75% WG (T₆), and Nicosulfuron 75% WDG (T₇) recorded comparatively lower weed control efficiency. The higher weed control efficiency under T₂ and T₄ indicated their superior effectiveness in suppressing mixed weed flora throughout the crop growth period. The results are consistent with Akhtar et al. (2017) [1] and Mastkar et al. (2022) [4] .

Conclusion

The study demonstrated that weed management practices significantly influenced weed density, weed dry matter, and weed control efficiency in maize. Among all the treatments, hand weeding at 30, 45 and 60 DAS (T₂) proved to be the most effective in suppressing weed growth throughout the crop growth period. Among the post-emergence herbicides, Mesotrione 2.27% + Atrazine 22.7% SC @ 80 + 795 g a.i.

ha⁻¹ applied at 30 DAS consistently recorded lower weed density and weed dry matter along with higher weed control efficiency, followed by Topramezone 33.6% SC @ 25.2 g a.i. ha⁻¹ (T₃). Therefore, the application of Mesotrione 2.27% + Atrazine 22.7% SC @ 80 + 795 g a.i. ha⁻¹ at 30 DAS can be considered an effective post-emergence weed management option for controlling mixed weed flora in maize under the agro-climatic conditions of Chhattisgarh.

References

1. Akhtar P, Kumar A, Kumar J, Sharma N, Stanzen L, Sharma A, et al. Bio-efficacy of post emergent application of tembotrione on mixed weed flora in spring maize (Zea mays L.) under irrigated sub-tropical Shiwalik foothills of J&K, India. Int J Curr Microbiol Appl Sci. 2017;6(12):1619-1626.
2. Chaudari DD, Patel VJ, Patel HK, Patel BD. Effect of weed control measures on weeds and yield of rabi (winter) maize. Indian J Weed Sci. 2023;55(3):260-263.
3. Chinyo M, Pratap T, Singh SP, Pareek N, Singh VV. The moisture regimes and herbicides efficacy in improving productivity and profitability of springplanted maize. Indian J Weed Sci. 2025;57(1):53-57.
4. Mastkar A, Kushwaha HS, Kewat ML. Weed control efficiency, yield attributes and yield of maize (Zea mays L.) as influenced by weed management practices. Ann Agric Res. 2022;43(3):267-271.
5. Mitra B, Bhattacharya PM, Ghosh A, Patra K, Chowdhury AK, Gathala MK. Herbicide options for effective weed management in zero-till maize. Indian J Weed Sci. 2018;50(2):137-141.
6. Kantwa S, Jadon CK, Ram B, Kantwa SR, Tetarwal JP, Kantwa SL, et al. Comparative efficiency of different weed management practices on economics as well as nutrient uptake in maize. Int J Econ Plants. 2023;10(1):31-36.
7. Kaul A, Singh B, Singh M. Weed management with pre-and post-emergence herbicides in kharif maize in sub-mountainous area of Punjab, India. Indian J Weed Sci. 2023;55(1):32-35.
8. Roy DK, Ranjan S, Sow S. Productivity and profitability of zero till winter maize as influenced by integrated weed management practices. Indian J Weed Sci. 2023;55(3):264-268.
9. Sandhya Rani B, Chandrika V, Reddy GP, Sudhakar P, Karuna Sagar G. Weed management with pre-and postemergence herbicides in maize under maize-greengram cropping system. Indian J Weed Sci. 2021;53(4):405410.
10. Sen S, Das TK, Dass A, Kumar D, Bhatia A, Bhattacharyya R, et al. Tillage, residue, nitrogen and herbicides effects on weeds and greengram productivity and profitability in conservation agriculture-based maize-wheat-greengram system. Indian J Weed Sci. 2024;55(4):380-387.
11. Gomez KA, Gomez AA. Statistical procedures for agricultural research. 2 nd ed. New York: John Wiley & Sons; 1984.