Role of Mineral Elements to Induce the Resistance of Arabica Coffee Against Rust Disease at Lowland Area

Abstract

Lowland arabica coffee can be affected by leaf rust and its decrease the coffee production up to 80%. The resistance level of the plant can be determined by the content of cellulose, lignin, calcium pectate, and polyphenols in leaf tissue. Many publications reported that the mineral element could increase the content of the metabolites. This study aimed to determine the effect of Si, B, I, Ca, and K on the incidence of leaf rust attack. The experiment was carried out at 400 m a.s.l. in 2018. The experimental subjects were KT variety, which was six years old. The experiment used a randomized block design with seven treatments. The results showed that there were 1) decrease the number of leaves affected by rust between first and second observation, and 2) compared to controls, all treatments has decreased the incidence of attacks leaf rust disease. Conclusion: There is a tendency of differences in the incidence rate of attack of leaf rust disease in each treatment. Control plants showed the highest incidence rate of 1.25%, while the lowest incidence was affected by Silica, iodine, and potassium, which were 0.63%. The treatment of silica and iodine was able to reduce the highest number of colonies Leaf Rust.