International Journal of Plant & Soil Science

Soybean (Glycine max) is a versatile legume crop crucial for global food security, edible oil production, livestock feed and soil health through crop rotation. The present study investigated the effect of three sowing dates on insect pest incidence as well as on yield of soybean crop. Seven insect pests were found to be associated with the crop belonging to three major insect orders viz., Whitefly (Bemisia tabaci), Aphid (Aphis fabae), Jassid(Apheliona maculosa), and Thrips (Thrips tabaci) from order Hemiptera and two species of Flea beetle (Alticahimensis and Luperomorpha xanthodera) of order Coleoptera, Cabbage looper (Trichoplusia ni) of Lepidoptera. The crop sown on the first sowing date (10^th June, 2023) had the highest infestation of sucking pests as compared to the other two sowing dates (25^th June and 10^th July, 2023) and observed that with the delay in sowing of soybean crops the population of sucking pest decreases while highest infestation of defoliators was recorded in crops sown on the third sowing date (10^th July, 2023) than soybean crop sown earlier. The study concludes that the sowing time significantly influences the incidence of all documented insect pest, with the exception for the cabbage looper, as well as on the yield of soybean. The maximum grain yield was harvested from the crop sown on 10^th of June, 2023 (1145 kg/ha) as these plants exhibited greater bushiness and vitality, characterized by a higher pod than other sowing dates (836.24 kg/ha for crop sown on 25^th June and 746.66 kg/ha for crop sown on 10^th July, 2023). Furthermore, the present study establishes that there was no significant yield reduction attributed to insect pests, as all recorded pests remained below the economic threshold level.