Evaluation of Weed Dynamics in Maize based Intercropping Systems for Rabi in North Coastal Andhra Pradesh
Abstract
Afield experiment was conducted at the Agricultural College Farm, Naira, during the rabi season of 2024–2025 to evaluate weed dynamics in maize-based intercropping systems under different nitrogen levels. The soil was sandy loam with low fertility status. The study followed a split-plot design with five main plots—maize intercropped with blackgram, greengram, cowpea, in-situ green manuringand sole maizeand three subplots involving 100% RDN, 75% RDN,and 75% RDN + biological fertilizer consortia. Results revealed that maize + cowpea in paired rows significantly reduced weed density and weed dry weight at all crop growth stages. This was attributed to the rapid canopy coverage and shading effect of cowpea, which suppressed weed germination. Sole maize recorded the highest weed density and dry weight, indicating poor weed suppression. Among nitrogen levels, 75% RDN produced the lowest weed density and dry weight, while 100% RDN recorded higher weed growth due to greater nutrient availability. The findings suggest that adopting maize + cowpea intercropping with 75% RDN can effectively reduce weed competition and improve resource efficiency.
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Introduction
Maize (Zea mays L.)is the third most widely grown crop in India after wheat and rice. In addition to providing human sustenance and high-quality animal feed, maize is utilized as a basic raw material and ingredient in thousands of industrial goods. These include starch, oil, protein, alcoholic beverages, food sweeteners, medications, cosmetics, and the production of bioenergy (Kumar et al. 2018). With a productivity of 3351 kg ha-1, maize produces approximately 37.67 million tonnes of grain annually on 11.24 million hectares in India (Directorate of Economics and Statistics, 2023-24). A total of 18.19 lakh tons of production and 6225 kg ha-1 of productivity were obtained from the 2.92 lakh hectares of maize planted in Andhra Pradesh (des.ap.gov.in, 2023-24). Intercropping in maize under crop intensification has increased recently in the North Coastal zone of Andhra Pradesh. While fertilization increases crop growth, excessive fertilizer application can exacerbate weed problems. There has been a noticeable improvement in weed control with intercropping systems. In addition to suppressing weeds, the intentional intercropping of legumes with maize aids in the plant'suptake of nitrogen from the atmosphere. Many scientists have also reported increased productivity and returns from intercropping combinations, as well as an improvement in maize yield brought about by the connection of legumes. Conventional spacing restricts the growth of related intercrops but may be beneficial for solitary crops. A reasonable amount of spatial adjustment to make room for intercrops aids in lowering intercrop competition. For successful intercropping, previous research also recommended using wider rows and growing maize in pairs by Rajashekarappa et al. 2018, Singh and Kumar, 2021and Sain et al., 2023.Keeping all these in consideration, present investigation as carried out to study different intercrops with maize at different nitrogen levels to evaluate the weed dynamics in the maize intercropping system in the North Coastal Andhra Pradesh.
Conclusion
From the experiment it can be concluded that among the weed indices, significantly lower weed density and lower weed dry weight were recorded under maize + cowpea with paired row planting indicating adoption of higher canopy crops improving weed smothering efficiency. Among the nitrogen levels, lower weed density and weed dry weight were recorded under 75 % RDN application. CONFLICT OF INTEREST The authors declare no conflict of interest.