Antagonist Test Of Streptomyces sp. Against Colletotrichum Sp. From Several Chili Varieties In Vitro

Abstract

Chili plants are horticultural commodities that play an important role in Indonesia's economic
development. Low chili plant production could be the consequents of anthracnose disease
(Colletotrichum sp.) with symptoms of the dry shrinked and blackening of the fruits. Up to this date,
chemical control with pestiside are the most widely used. Excessive use of chemical pesticides can
led to environmetal pollution and ecosystem damage. Therefore, biological control that organic and
safe for the environment were applied. The antagonistic agents in the form of Streptomyces sp. were
employed as one of the way to suppress pathogen growth. The study aimed to determine the potential
of Streptomyces sp. in inhibiting the growth of Colletotrichum sp. from several chili varieties. A
Completely Randomized Design method was used, with 3 treatments (large chili, curly chili and
cayenne pepper) and 6 replications. Chili fruit exhibited the anthracnose symptoms was isolated and
Colletotrichum sp infection was validated. Furthermore, antagonistic tests were carried out against
Streptomyces sp. against the pathogen, three isolates are antagonistic as indicated by the interaction
of mechanism in the form of antibiosis produced by bacteria in inhibiting the pathogen that causes
anthracnose disease. The result show that CR isolate has 50.13% inhibition. This is significantly
different from the other two isolates, CB and CK, with 34.49% and 30.34% inhibition.