The influence of plant covering on temperature and relative humidity in the canopy and the development of read stripe of rice

English. Experiments to evaluate the effect of plant covering on the temperature and relative humidity in the plant canopy and the development of red stripes have been conducted during the dry season of 1993 and the wet season of 1993/1994. In both season, the experiments were arranged in a split plot treatment arrangement with three replications. Rice varieties of IR36, IR64, Cisadane, and Ciliwung, were grown as main plots and the plants covered with different materials (cheeth cloth, plastic and check) were as sub plots. Plants were inoculated with suspected bacterial isolates, isolated from naturally infected plants when plants were at early flowering stages. Results of these experiments indicated that rice variety and plant covering significantly affected the development of red stripe. During the dry season of 1993, red stripe developed more severely on IR36 and IR64 than on Cisadane and Ciliwung. While during the wet season of 1993/1994, red stripe developed well on all varieties tested. Materials of plant cover did not significantly affect temperature and relative humidity, however it did significantly affect the development of red stripe in both season. Red stripe developed very well on temperature more than 30 percent and relative humidity of more than 90 percent

Indonesian. Penelitian untuk mempelajari pengaruh suhu dan kelembaban terhadap penyakit hawar daun jingga padi telah dilakukan di Kebun Percobaan Sukamandi pada MK 1993 dan MH 1993/1994. Percobaan ditata dalam rancangan acak terpisah dengan 3 ulangan. Varietas padi IR36, IR64, Cisadane, dan Ciliwung, ditanam sebagai petak utama dan perlakuan penyungkupan, sebagai anak petak. Perlakuan penyungkupan dimaksudkan untuk memperoleh variasi suhu dan kelembaban. Inokulasi tanaman dilakukan pada saat pertanaman mencapai stadium awal pembungaan. Hasil penelitian menunjukkan bahwa varietas dan jenis sungkup berpengaruh nyata terhadap penyakit hawar daun jingga. Pada MK 1993 dibandingkan dengan perkembangan penyakit pada varietas Cisadane dan Ciliwung hawar daun jingga berkembang lebih baik pada varietas IR36 dan IR64. Sementara pada MH 1993/1994, penyakit berkembang baik pada semua varietas yang ditanam, walaupun perkembangan pada masing-masing varietas berbeda nyata. Bahan penyungkup tidak nyata berpengaruh terhadap suhu dan kelembaban relatif, namun penyungkupan nyata meningkatkan suhu dan kelembaban relatif. Penyungkupan nyata meningkatkan keberadaan hawar daun jingga pada kedua musim. Penyakit hawar daun jingga berkembang baik pada kondisi suhu di atas 30 derajat C dan kelembaban 90 persen