Assessing the Resistance of Different Chili Genotypes to Chili Leaf Curl Virus (Chilcv) and Evaluating Insecticides for Controlling its Vector, Bemisia Tabaci

Abstract

The production of chili in Pakistan is currently facing a significant threat from Chili leaf curl virus (ChiLCV). A study was conducted in the crop growing seasons 2019-2020 and 2020-2021 at Ayub Agriculture Research Institute Faisalabad to assess the susceptibility and resistance of nine chili genotypes to ChiLCV. Each genotype was replicated three times by using the Randomized Complete Block Design. Weekly documentation was carried out to record the incidence and severity of the disease. During the first and second crop growing seasons, it was observed that, Tarapuri (78%, 76.9%), CH 107 (67.8%, 63.7%), Talhari (65.7%, 56.8%), CH 109 (52.7%, 54.4%), CH 108 (50.8, 51.1), and GSL-111 (42.6%, 39.5%) genotypes showed susceptible response to ChiLCV. The two genotypes Hybrid-46 (17.7%, 18.5%) and Hot Queen (15.5%, 13.4%) exhibited a moderately resistant response and only one genotype CBS1292 (40.7%, 39.1%) showed a moderately susceptible response against ChiLCV. The results of the screening experiment indicated that a majority of chili varieties exhibit susceptibility to chili leaf curl disease and the most of the germplasm is deficient in terms of providing protection against the disease. In addition, another study was conducted to evaluate the effectiveness of five insecticides, namely Acephate 75 SP, Emamectin, Imidacloprid, Diafenthiuron, and a combination of these insecticides, in managing percent disease incidence, reducing whitefly population, and enhancing crop yield. Among the various insecticides evaluated, Diafenthiuron exhibited the highest efficacy in reducing disease incidence (7.70%, 6.66%), reducing white fly population (1.80, 1.56), and increasing the yield of green fruit (120.71, 132.52q/ha) followed by combination of all of these inecticides, Imidacloprid, Emamectin, and Acephate during both crop growing seasons. This approach has proved a high level of safety and ecological compatibility, and it appeared to be a practical disease management tool.