Pestalotiopsis sp. infection causes leaf fall disease of new arrivals in several clones of rubber plants

Abstract. Damiri N, Pratama Y, Febbiyanti TP, Rahim SE, Astuti DT, Purwanti Y. 2022. Pestalotiopsis sp. infection causes leaf fall disease of new arrivals in several clones of rubber plants. Biodiversitas 23: 3943-3949. This study aims to investigate the response of rubber clones commonly cultivated by farming communities to infection with the new leaf fall pathogen of Pestalotiopsis in rubber plantations. The study was conducted in smallholder rubber plantations, laboratories and greenhouses Department of Pests and Plant Diseases, Faculty of Agriculture, Sriwijaya University. The study consists of two stages. The first stage was a survey of the leaf fall disease of Pestalotiopsis in smallholder rubber plantations in Banyuasin Regency. The second stage was testing the isolates of Pestalotiopsis sp. against several rubber clones in the greenhouse using the Randomized Block Design (RBD) method, with six treatment clones and six replications. Each replication consisted of three polybags. The treatments tested were rubber plant clones aged four months, namely rubber clones PB 260, RRIC 100, IRR 112, IRR 118, BPM 24 and PB 340. The inoculated leaves were rubber leaves aged 10 days after opening. The results showed that Pestalotiopsis leaf fall disease in 10 smallholder rubber plantation areas in the field showed that new leaf fall attacks caused by the Pestalotiopsis fungus on smallholder rubber plants ranged from 80 to 100 percent with a decrease in production between 20 to 50 percent. All clones planted were susceptible to this new disease, which resulted in a very significant reduction in yield. The treatment of Pestalotiopsis sp. inoculation on six rubber clones significantly affected the severity of Pestalotiopsis new leaf fall disease. Effect of Pestalotiopsis sp. the number of rubber leaves that fall is very significant. The rubber clone that experienced the most leaf fall due to disease was PB 340 although the percentage of leaf fall was not significantly different from the treatment of PB 260 but significantly different from the treatment of clones RRIC 100, IRR 112, IRR 118 and BPM 24. The percentage of Pestalotiopsis leaf fall experienced by clones PB 340 reached 47.19% while the RRIC 100 clone was only 4.98%.