Effect of rice genotype, fertilizers, and fungicides on intensity of rice neck blast

English. The effect of rice genotype, fertilizers, and fungicides on intensity of rice neck blast (RNB) disease was evaluated in Purwakarta during the 1999/2000 wet season. Eight genotypes were evaluated for their resistance to the neck blast in an experiment with Randomized Block Design. The effect of fertilizers on the disease intensity was evaluated in an experiment using a split-plot design. Two rice varieties Cirata and Limboto were used as main plots, while fertilizer combinations were sub-plots. Evaluation on effect of fungicides was also done in a split-plot design. The fungicides that were applied at different time of application were the main plots and kind of fungicides were the sub plot. All experiments were done with three replications. Results of the experiments indicated that rice genotype, fertilizers, and fungicides significantly affected the severity of RNB. The intensity of RNB was higher (73.85 percent) on cultivar Cirata than on Jatiluhur (3.65 percent). RNB developed well on rice plants with high rate of nitrogen fertilizer (300 kg urea/ha). The time of fungicide application significantly affected the intensity of RNB. The fungicides reduced the intensity of RNB and yield losses by 31.4-36.1 percent and 72.7-82.8 percent respectively.

English. Penelitian dilaksanakan di Purwakarta pada MH 1999/2000 dalam tiga percobaan terpisah. Delapan genotipe padi diuji ketahanannya terhadap penyakit blas leher dalam suatu percobaan yang dirancang secara acak kelompok. Pengaruh pupuk terhadap blas leher diuji dalam suatu percobaan yang ditata dalam rancangan petak terpisah. Varietas padi Limboto dan Cirata ditempatkan sebagai petak utama dan kombinasi pupuk yang berbeda sebagai anak petak. Pengaruh fungisida dievaluasi dalam percobaan yang ditata dalam rancangan petak terpisah. Waktu penyemprotan ditempatkan sebagai petak utama dan jenis fungisida sebagai anak petak. Semua pengujian dilakukan dengan tiga ulangan. Hasil percobaan menunjukkan bahwa genotipe, pupuk, dan fungisida berpengaruh nyata terhadap intensitas penyakit blas leher. Keparahan penyakit tertinggi terdapat pada varietas Cirata (73,85 persen), sedangkan terendah pada varietas Jatiluhur (3,65 persen). Pemberian pupuk K dapat menekan intensitas penyakit, sedangkan pupuk N menyebabkan tanaman menjadi lebih rentan. Penggunaan fungisida dapat menekan keparahan penyakit blas leher dan menekan kehilangan hasil berturut-turut sebesar 31,4-36,1 persen dan 72,7-82,8 persen.