Screening of Ginger Genotypes against Rhizome Fly, Mimegralla sp. (Diptera: Micropezidae) in Kapurkot, Salyan, Nepal

Abstract

An experiment was conducted to evaluate 25 indigenous ginger genotypes against rhizome fly, Mimegralla sp. at the Ginger Research Program, Kapurkot, Salyan, Nepal in 2024/25 and 2025/26. Planting was done at the crop geometry of 30 cm x 30 cm in the plot size of 3 m x 0.6 m (1.8 m²) during the last week of March and each experimental plot was replicated thrice in Randomized Complete Block Design (RCBD). Tiller number, plant height and rhizome fly infected plants scoring were recorded at the full crop growth stages whereas rhizome yields were recorded during harvesting. The rhizome fly infestation was scored by using 1 -5 scoring scale (GRP, 2014), as 1 = not infected, 2 = 0 to 25% infected, 3 = 25 – 50% infected, 4 = 50 – 75% infected and 5 = 75 – 100% infected rhizome. Analysis of variance (ANOVA) was employed to detect significant differences and mean comparisons was done by Duncan's Multiple Range Test (DMRT). Significant difference occurred among the ginger genotypes in terms of growth traits, pest infestation levels, and fresh rhizome yields. Ginger genotypes ZI 9805, ZI 0403 and ZI 0515 produced significantly the highest fresh rhizome yield (27.07-27.56 t/ha, 24.49-27.50 t/ha and 24.39-27.20 t/ha, respectively). Ginger genotypes ZI 9805 was found highly promising for lower rhizome fly infestation (0.0-0.5% rhizome fly infested, 1.0 rhizome fly scoring, 0.13-0.33 maggots/rhizome, 0.07-0.20 pupae/rhizome and 0.40-0.41 t/ha rhizome fly infested ginger) and higher ginger rhizome yield (27.07-27.56 t/ha fresh ginger) followed by fly tolerant genotype ZI 0403 (24.49-27.50 t/ha fresh ginger). The results indicated that utilizing resistant and tolerant genotypes like ZI 9805 and ZI 0403 could be the sustainable strategy to mitigate pest damage and increase production/productivity of ginger in Nepal.