Uji Efektivitas Beberapa Jenis Bahan Aktif Fungisida dan Ketahanan Varietas Padi Ciherang dan Inpari 32 terhadap Isolat Rhizoctonia solani Asal Percut Sei Tuan

Abstract

Rice leaf sheath blight, caused by the fungus Rhizoctonia solani, is a disease that is currently developing and widespread in rice producing areas in Indonesia. This disease is very difficult to control because it has a wide host range. This study was aimed to evaluate the effectiveness of several fungicide active ingredients in sup pressing the development of rice leaf sheath blight in Percut Sei Tuan District, Deli Serdang Regency. The research was carried out in the laboratory and in the screen house. Research in the laboratory used a completely randomized factorial design (CRD) with 3 replications and 2 factors. The first factor was the active ingredient, namely: F0 (control), F1 (Tebuconazole 25%), F2 (Difenoconazole 250 g/l), F3 (Karbendazim 80% ), with 6 levels of concentration (ppm) in PDA media namely: 0 ppm (control), 5 ppm, 10 ppm, 25 ppm, 50 ppm, 100 ppm as the second factor. while the study in the screen house was carried out with a factorial Randomized Block Design (RBD) with 3 replications and 2 factors namely Fungicide as the first factor consisting of: F1 (Tebuconazole 25%), F2 (Difenoconazole 250 g/l), F3 (Karbendazim 80%) , with 2 varieties of rice plants namely: Ciherang and Inpari 32 as the second factor. The results of the research showed that the active ingredi ent was able to inhibit the growth of R. solani in vitro using the toxic bait method, namely Tebucomazole 25% (F1) and Difenoconazole 250 g/l (F2), the highest dis ease incidence rate was in the Ciherang + Difenoconazole 250 g/l treatment namely 43.44%, the lowest incidence rate was in the Inpari 32 + Carbendazim 80% treatment namely 36.67%, the lowest disease severity was in the Ciherang + Tebu conazole 25% treatment namely 53.40%, while the highest severity was in the Inpari 32 + Difenoconazole treatment. 250 g/l namely 71.28%, in rice production for filled grains in the Ciherang + Tebuconazole 25% treatment namely 452 g with an empty grain weight of 20.00 g, while Ciherang + Carbendazim 80% had a full grain weight of 334.6 g with empty grains 21.5 g hollow grains