Identification of Climate Influence on Upas Fungus (Corticium sp.) Disease Intensity on Rubber Plants (Hevea brasiliensis Muell.Arg.)

Abstract

This research aims to determine the influence of climate in West Kutai, Indonesia on the intensity of disease attack Upas Fungus (Corticium sp.) pathogen on 4-year-old and 7-year-old rubber plants. The study began in 2015, with a 4-year-old rubber plant and continues in 2018 with a 7-year-old rubber plant. The methodology is to inventory 500 rubber plants in two neighboring locations to determine the incidence and severity of disease caused by Upas Fungus in 2015. The results indicated that an invasion of pathogenic Upas Fungus attacked rubber plants starting at the age of 4 years in 2 places and the age of 4 years in another location. Symptoms included substantial eruptions of tree trunks that finally dried up. The inventory and calculation results indicate that the attack frequency at position 1 is 1.20 % with an attack intensity of 0.90 %, and the attack frequency at location 2 is 2.40 % with an attack intensity of 1.80 %. The correlation test revealed an inverse (negative) relationship between temperature and attack intensity, with a coefficient value of 0.721, and a directly proportional (positive) relationship between humidity and intensity, with a coefficient value of 0.754 and vice versa, between rainfall and intensity there is an inverse (negative) relationship that is not significant with a coefficient value of 0.199 and vice versa.