Bio-efficacy of cow-urine-based neem, nochi and adhatoda extracts against sucking pests and impact on natural enemies in organic rice

      To overcome the adverse effects of synthetic pesticides in rice, organic farming by utilizing botanicals is a viable alternative. The bio-efficacy of cow-urine-based extracts of neem (Azadirachta indica), nochi (Vitex nigundo) and adhatoda (Adhatoda vasica) was studied. The experiments targeted major sucking insect pests, brown plant hopper (BPH) and green leaf hopper (GLH), in wetland paddy fields, Tamil Nadu Agricultural University, Coimbatore, during Rabi 2023. The results showed that the cow-urine-based extracts of neem, nochi and adhathoda (NNA) leaves @15 % were most effective against BPH and GLH with 70.23 and 72.48 percent reduction over control (PROC), which was on par with NNA leaf extract @10 % and the PROC were 67.13 and 68.18, respectively. Individual 10 % leaf extracts of Neem, Nochi and Adhatoda recorded lower PROC values against BPH (53.68 %, 55.40 % and 53.68 %) and GLH (52.68 %, 55.75 % and 53.02 %) compared to the combined NNA extract at 15 % and 10 %. The neem, nochi and adhatoda (NNA) leaf extract @ 15 % has a moderate impact on beneficial arthropods, expressed as percent impact over control (PIOC) for natural enemies like spiders (27.70), coccinellids (32.99), rove beetles (10.88), mirid bugs (19.95) and ground beetles (43.99). Foliar application of NNA leaf extract at 10 % resulted in lower PIOC values (26.28 %, 31.33 %, 10.14 %, 18.74 % and 39.86 %, respectively, for spiders, coccinellids, rove beetles, mirid bugs and ground beetles), indicating its relative safety for beneficial arthropods. The eco-friendly, cost-effective and residue-free nature of the cow-urine-based neem, nochi and adhatoda leaf extract can be easily incorporated into the Integrated Pest Management programmes in the organic rice production system.