Evaluation of Locally Available Botanicals for the Management of Maize Weevil (Sitophilus zeamais Motsch.) in Room Storage Condition

From April to July 2019, an experiment was conducted in Khumaltar, Lalitpur (27°39.312′N, 85° 19.586′E, and 1322 m above sea level) to assess the effectiveness of plant materials on maize weevil (Sitophilus zeamais Motsch.) control under laboratory conditions (maintained room temperature of 28.5 ± 2°C, and relative humidity of 72 ± 5%) treatments were Acorus calamus (rhizome powder) @ 5 g·kg−1, Melia azadirach (rhizome powder) seed) @ 5 g·kg−1, Curcuma domestica (rhizome powder) @ 5 g·kg−1, mustard oil @ 2 mL·kg−1, Gingiber officinalis (rhizome powder) @ 5 g·kg−1, rice husk ash @ 5 g·kg−1, and an untreated control. These treatments were evaluated in a completely randomized design (CRD) with three replications. At four months, the grains treated with Acorus calamus had the least weight loss (6.66%), and grain damage (1.23%). Grain damage (18%), and weight loss (62.33%) were the highest in the control treatment. Similarly, grains treated with Acorus calamus had the fewest number of exit holes (3.10 per 100 g of maize seed), while the control treatment had the largest number of exit holes (45.10 per 100 g of maize seed). There was a significantly higher number of weevils in the control treatment (55.80 per 250 g maize grains), but only a few numbers of weevils in the Acorus calamus-treated grains (2.50 per 250 g maize grains). In contrast with other plant materials treated grains, the maize weevil showed a reduced preference for Acorus calamus- treated grains with low weight loss, and grain damage. These findings can be used to promote locally accessible botanicals for maize weevil control in Nepal.