Comparative Studies on the Different Management Strategies of Citrus Greening Disease in Mandarin (Citrus reticulata Blanco.) at Dailekh, Nepal

Abstract

Citrus greening (Candidatus Liberibacter asiaticus) is an important disease of different Citrus species, including Mandarin, globally. There is a growing need for the sustainable management of this disease since the chemical approaches have led to pathogenic resistance and health concerns. A research study was conducted at Dailekh, Nepal to evaluate the field efficacy of different chemicals and biopesticides against greening disease in Mandarin (Citrus reticulata Blanco) following a biological survey on disease prevalence. The iodine-based starch test showed the disease prevalence to be 28.07 % and the disease severity to be 0.184 in the Dailekh district. The field experiment was laid out in Randomized Complete Block Design (RCBD) with 3 replications and 10 treatments of botanicals, biocontrol agents, and chemical consortia. Results revealed that the highest percentage reduction over control was found in the plot treated with (Imidacloprid + Copper oxychloride), (Neem oil + Bacillus amyloliquefaciens) and (Bacillus thuringiensis + Bacillus amyloliquefaciens.) Hence, based on the result of the study, foliar application of Imidacloprid @ 0.02% + Copper oxychloride @ 0.025%, Neem oil @ 5 ml/l + Bacillus amyloliquefaciens @ 5 ml/l and Bacillus thuringiensis @ 2 ml/l + Bacillus amyloliquefacians @ 5 ml/l at monthly interval were found effective in reducing the severity of citrus greening disease in Mandarin.

SAARC J. Agric., 24(1): 1-18 (2026)