MANAGEMENT OF BLAST DISEASE (Pyricularia grisea) OF JIRA KATARIBHOG RICE

Abstract

Evaluation of various fungicides, disease resistance inducing chemicals and poultry litter against blast disease (Pyricularia grisea Sacc) of rice was conducted at Hajee Mohammad Danesh Science and Technology University, Dinajpur during the period of July-December 2014. A highly susceptible rice variety Jira Kataribhog was transplanted in Randomized Complete Block Design with three replications and the application of fungicides viz. Tilt 250EC, Bavistin DF, Trooper 75WP, resistance inducing chemicals viz. Salicylic acid, Riboflavin (B2) and Poultry litter were given thrice at 15-d interval commencing from 30 DAT. Data were collected on number of leaf spot per hill, leaf, neck and node blast severity and yield. The leaf blast intensity was recorded at 37 DAT, 56DAT and 63DAT while the neck blast severity were recorded at 90 and 105 DAT. The highest number of leaf spots per hill at 37, 56 and 63 DAT were found in control (17.00, 19.07, 21.07) and the lowest (6.73, 2.43) were found in Trooper 75WP sprayed plot but found else in Bavistin DF sprayed plot (12.87) at 37 DAT. In case of percent leaf blast severity at 37, 56 and 63 DAT, the highest leaf blast severity were observed in control plot (6.03, 6.07, 6.17) and the lowest was found in Trooper 75WP sprayed plot (1.97, 1.07) except Bavistin DF sprayed plot (3.53) at 37 DAT. The results revealed that percent decrease of leaf blast severity was the highest (82.66) in Trooper 75WP sprayed plots over control. The highest percent infected necks (6.40%, 5.10%) were observed in control plots and the lowest (2.53%, 1.80%) were in Trooper 75WP sprayed plot. The percent infected node were recorded at 105 DAT where the highest percent infected node (5.20%) was found in control and the lowest infected node (1.73%) was recorded in Trooper 75WP sprayed plot. The yield loss were calculated and found the highest yield loss (3.65%) in control and the lowest yield loss (1.44%) in Trooper sprayed plot. The 1000-grain weight was the highest in Trooper sprayed plot (11.41g) and the lowest in control plot (9.86 g). Moreover, the highest yield per plot (3.63 Kg) was recorded in Trooper 75WP sprayed plot and the lowest yield (2.67 Kg) was obtained from control plot and the highest yield (4.54 t/ha) was recorded in Trooper 75WP sprayed plot and the lowest yield (3.33 t/ha) was obtained in control plot. The highest yield increase was obtained 36.34% in Trooper 75WP sprayed plot over control. Finally it may be concluded that Trooper 75WP contributed effectively in controlling blast disease of Jira Kataribhog rice with focusing very significantly higher yield.