PENGARUH PENYAKIT KRUPUK TERHADAP HASIL DAN MUTU DELAPAN VARIETAS TEMBAKAU VIRGINIA

The effect of tobacco curl disease on the yield and quality of eight Virginia tobacco varietiesTobacco leaf curl disease is one of the important diseases on Virginia tobacco which especially occurs in dry condition. The use of resistant varieties is one of the most effective way to control the disease. This experiment was lo evaluate the effect of tobacco curl disease on tobacco varieties (DB 101, Coker 319, Coker 176, Coker 48, Coker 86, and Coker 371 Gold) and two promising lines (T.45/T.65 and T.45/T.69). The experiment was conducted in Pekuwon, Sumberrejo, Bojonegoro from April to October 1997. The experiment was arranged in randomized block design with three replications. The tobacco seedlings wee transplanted in 0.9 m x 0.6 m spacing and 9.0 m x 9.0 m plot size. The fertilizer dosage applied are 300 kg ZA + 108 kg SP-36 + 156 kg ZK per ha The parameters observed including percentage of diseased plant, productive leaves, as well as the yield and quality of leaves. The esults showed that Coker 371 Gold variety showed the lowest disease percentage (6.89%), decrease in productive leaves was high (71.86%), Whereas the two promising lines, were T.45/T.6S and T.45/T.69 showed that the percentage of diseased plants wee not significantly different compared with DB 101, Coker 319, and Coker 48, but the decrease in productive leaves was lower. The yield of these promising lines were 10.12-10.30 kg/81 m!, grade indexes 86.04-87.27, and crop indexes are 88.31-88.63. Coker 176 was the most susceptible variety. The percentage of diseased plant, flue- cured yield, grade index, and crop index on Coker 176 wee 42.67%, 7.77 kg/81 m!, 86.09, and 66.89, respectively.