Efficacy of eco-friendly insecticides against yellow stem borer under spring rice crop ecosystem of Saptari district, Nepal

Abstract

The study aimed to assess the effectiveness of eco-friendly insecticides in controlling yellow stem borer in spring rice crops of Hardinath-1 variety in Saptari district, Nepal. For this experiment, a Randomized Block Design was used with seven different treatments and an untreated control group. The treatments tested included Bacillus thuringiensis var kurtaski, Beauveria bassiana, Azadiractin 2.00%, garlic extract, tobacco extract, larvosin, and an untreated plot.  The plots used were 3 × 4 meters in size and the plants were spaced 20 centimeters apart in both rows and between plants. The crop was sprayed twice, once during the vegetative stage and once during the reproductive stage, when the pest population reached a certain level. The incidence of dead heart was observed on ten randomly selected hills from each plot before and after the insecticide application, and observations on yellow stem borer incidence were recorded. Results showed that B. thuringiensis var kurtaski had the lowest dead heart infestation (0.4889%) and the minimum white head infestation (0.367%), as well as the highest mean yield (5.755mt/ha). Neembicide and B. bassiana also showed promising results.