Control of xylem limited bacterium (XLB) disease of clove and its insect vector with biocontrol agents

Abstract

Abstract An experiment was conducted under field condition in Wonogiri, Central Java in 2018 to evaluate the effectiveness of biological control agents against xylem limited bacterium disease and its insect vector (Hindola striata). The experiment was arranged in a completely randomized block design with 12 treatments and 4 replicates. Treatments used were (1) fipronil, (2) Beauveria bassiana, (3) bioprotector, (4) oxytetracycline, (5) Bacillus sp. - Pseudomonas, (6) oxytetracycline + fipronil, (7) oxytetracycline + bioprotector, (8) oxytetracycline + B. bassiana), (9) Bacillus sp. - Pseudomonas + fipronil, (10) Bacillus sp. - Pseudomonas + bioprotector), (11) Bacillus sp. - Pseudomonas + B. bassiana, and (12) control (water). Infected clove plants were treated twice with monthly application interval. Variables observed were the population of H. striata, percentage of plant damage, and the plant shoots growth. Treatments of oxytetracycline, fipronil, oxytetracycline + fipronil, Bacillus sp.-Pseudomonas, oxytetracycline + B. bassiana, and Bacillus sp. - Pseudomonas + B. bassiana could reduce 100% population of H. striata. Treatments of Bacillus sp. - Pseudomonas + B. bassiana could inhibit the plant damage percentage up to 91.94%. While, treatments of Bacillus sp. - Pseudomonas + B. bassiana, Bacillus sp. - Pseudomonas + fipronil, and oxytetracycline + fipronil stimulated the plant shoots growth.