Efektivitas Streptomyces spp. sebagai Agensia Hayati Mikrob Patogen pada Tanaman Cabai Besar (Capsicum annuum)

Abstract

Pepper is one of important horticulture plants but it’s productivity has decreased, due to microbial pathogens. Streptomyces spp. indigenous isolates have been reported to have capability to produce antimicrobial compounds. This research aimed to assess the ability of Streptomyces spp. LSW05 and PS4-16, two potential isolates based on previous in vitro assay, in controlling microbial pathogens, particularly Cercospora sp., in pepper plant in a field trial and to obtain an effective application method. The two isolates were applied singly or in combination using three methods (seed coating, soil drenching, and plant spraying). Streptomyces treatment significantly supressed disease severity and increased plant height and fruit production. Soil drenching with combination of the two isolates was the best treatment to suppress disease with the value of area under the disease progress curve (AUDPC) was only 234 with relative control effectiveness up to 81%. Plant sprayed with combination of the two isolates produced the highest fruits number (697 g/plot). Seed coated with PS4-16 isolate was the best treatment to increase plant height with the value of area under the height progress curve (AUHPC) was 1350, which was 27% higher than the non-treated plants. Seed coating with the combined isolates increased plant dry weight by 143%. Cost analysis showed that seed coating with the two isolates gave the highest profit as high as Rp 9.869.600 with relative control effectiveness up to 43%.