Evaluation of Tephrosia purpurea and Eucalyptus spp. Leaf Extracts for Eco-Friendly Weed Management in Maize and Brinjal

Weed infestation is a major constraint to crop productivity, particularly in organic and low-input systems where reliance on synthetic herbicides is restricted. This study evaluated the weed-suppressive potential of botanical extracts in maize and brinjal under field conditions. The experiment was conducted during 2024–2025 at Kumaraguru Institute of Agriculture using a Randomised Block Design. Treatments included combinations of kolunji extract, Eucalyptus extract, cow urine and neem oil, along with an untreated control and a weed-free treatment maintained by hand weeding. Weed population, weed dry weight, weed control efficiency, weed index, leaf area index and economic returns were assessed. Among the botanical treatments, T4, comprising kolunji extract 10% + Eucalyptus extract 10% + neem oil 10%, consistently recorded better weed suppression than the other botanical combinations. In maize, T4 recorded the lowest weed population and dry weed weight among botanical treatments at both 30 and 50 DAS, with weed control efficiency of 20.00% and 38.33%, respectively. In brinjal, T4 also showed comparatively better suppression, with 20.69% weed control efficiency at 40 DAS. The weed-free treatment recorded the highest LAI and yield, but T4 produced the highest benefit–cost ratio (1.18). The findings indicate that the kolunji + Eucalyptus + neem oil combination may serve as an eco-friendly component of integrated weed management, although it should be supplemented with other weed-control practices.