Endophytic bacteria as biocontrol agents of leaf spot disease (<i>Curvularia oryzae. Bugnic</i>) on rice

Abstract Leaf spot caused by Curvularia oryzae is an important disease on rice that can cause losses of 20 - 50%. Endophytic bacteria are a biological agent that can be used to control plant pathogenic fungi. The aim of the research is to obtain endophytic bacteria that are able to control leaf spot diseases ( C. oryzae ) and increase the growth of rice. The research used a Randomized Blok Design (RBD) with 7 treatments and 3 replications. The treatment consisted of 6 species of endophytic bacteria and control, the treatments were Bacillus cereus Se07, Bacillus cereus P14, Serratia marcescens ULGIE4, Serratia marcescens JB1E3, Bacillus sp. SJI, Bacillus subtilis , and control. The test was conducted in planta, the introduction of endophytic bacterial suspension was carried out twice (on the seeds and roots of rice seedlings) using the immersion method. C. oryzae inoculation was carried out on the leaves of rice (35 days after planting) using the leaf wounding method. Observations were made on disease development (incubation period, incidence and severity of disease), and plant growth (plant height, number of leaves and number of tillers). The endophytic bacteria that was able to control leaf spot and increase rice growth was Bacillus cereus Se07.