Induction of systemic resistance in Arabica coffee (Coffea arabica L.) against coffee berry disease (Colletotrichum kahawae Waller & Bridge) mediated through plant defense activator

The effect of exogenous application of Monopotassium phosphate, Dipotassium phosphate, Jasmonic acid and Salicylic acid (SA) in triggering systemic resistance in Arabica coffee against coffee berry disease (CBD) was studied in artificially inoculated cultivars with known resistance levels. The results showed that the chemicals had no antifungal effect against Colletotrichum kahawae at the concentration tested except SA at higher concentrations. However, the chemicals significantly (p < 0.05) reduced severity of CBD in all coffee cultivars. There was a significant (p < 0.05) interaction effect between plant defense inducing chemicals (PDIC) and coffee cultivars on disease development. The highest disease reduction was recorded in the hypocotyls treated with SA followed by Jasmonic acid. Application of SA at 10.0 mM reduced the disease severity by more than 50% and 65% on seedlings of highly and moderately susceptible coffee cultivars 370 and 74110, respectively. The study revealed that induction of systemic resistance in coffee provides new insight to manage CBD by contributing towards integrated disease management strategy.