NFLUENCE OF INTEGRATED APPROACH FOR CONTROLLING PYRICULARIA ORYZAE CAUSING BLAST FOR JIRAKATARIBHOG RICE

Abstract

This research program was designed to investigate the management of Pyricularia oryzae causes blast of Jirakataribhog rice (BR-34), Dinajpur during July-December 2016. Seven treatments viz. Nativo 75WG (0.61g/L), Trooper 75WP (0.75g/L), Filia (2ml/L), 3-foliar spray of urea (1.0%), 5-foliar spray of urea (1.0%), poultry litter (200g/m2 ) and control (plain water) were evaluated against the disease. Fungicides were applied thrice on the 30, 45, 60 DAT and urea spray with 15-day interval where the leaf disease intensity were recorded at 37 DAT, 52 DAT and 67 DAT but neck, node and collar blast once at 115 DAT. The experiments were laid out in factorial Randomized Complete Block Design (RCBD) with three replications. The whole plot was divided into three blocks where each block constituted factor „A‟ contained three doses of urea (60, 90, 120kg) and factor „B‟ contained the fungicides, compost and foliar application of urea. Data were assessment on number of spot and infected leaf, leaf disease severity, neck, node, collar blast severity and yield. In the 37 DAT, the number of spot, infected leaf and leaf blast severity were 252.2, 26.36 and 2.58% in control plot where 102.0, 11.33 and 0.60% were in Filia sprayed plot, respectively. In case of at 52 DAT, the highest number of leaf spot, infected leaf and leaf blast severity were 88.31, 13.85 and 0.94% in control plot and the lowest were 18.12, 5.84, and 0.18% in Filia sprayed plot, respectively. At 67 DAT, the highest number of spot, infected leaf and leaf blast severity were 18.10, 5.42 and 0.31% in control plot and the lowest number were 4.12, 1.74 and 0.12% in Filia sprayed plot, respectively. The result demonstrated that Filia (Propiconazole & Tricyclazole) spray reduced gradually the number of leaf spot, infected leaf, leaf blast severity significantly and eventually. Urea applications reduced the blast incidence insignificantly throughout the cropping period. In this study, the interaction of fungicide, urea spray and poultry litter with urea doses have been evaluated and found excellent and promising significant results in a Tropper spray with 90 kg urea applied plot in gradually reducing the number of leaf spot and infected leaf, leaf blast severity, number of infected neck, node and collar which was statistically similar with Filia spray in 90 kg urea fertilizer applied plot. In case of neck, node and collar blast incidence, the highest number were 2.30, 1.67 and 2.11 in control plot and the lowest number were found 0.37, 0.27 and 0.31 in Filia sprayed plot, respectively where the difference was statistically significant. In case of urea application, the highest number of neck, node and collar blast were 1.35, 0.83 and 1.11 in 90 kg urea fertilizer sprayed plot and lowest number of neck, node and collar blast were 0.87, 0.75 and 0.86 in 120 kg urea fertilizer applied plot, respectively. In this interaction effects, the highest number of neck, node and collar were 2.59, 1.89 and 2.56 in 60 kg urea fertilizer along with control plot and the lowest number of neck, node and collar were 0.23, 0.22 and 0.18 in 90 kg urea fertilizer along with Trooper sprayed plot, respectively that provided good protection to rice blast disease efficiently and significantly. Regarding the yield parameters, the lowest 1000-seed weight, grain yield and biological yield were 10.09g, 1.28 (t/ha) and 7.00 (t/ha) in control plot and the highest 1000-seed weight, grain yield and biological yield were 12.04g, 1.94 (t/ha) and 8.57 (t/ha) in Filia sprayed plot, respectively. In case of urea fertilizer, the lowest 1000-seed weight, grain yield and biological yield were 10.72g, 1.51 (t/ha) and 7.52 (t/ha) in 120 kg urea fertilizer applied plot and the highest 1000-seed weight and biological yield were 11.26g and 8.04 (t/ha) in 60 kg urea fertilizer applied plot whereas grain yield was 1.63 (t/ha) in 90 kg urea fertilizer applied plot. In the interaction, the lowest 1000-seed weight, grain yield and biological yield were 0.87g, 1.20 (t/ha) and 6.70 (t/ha) in 60 kg urea fertilizer along with Trooper sprayed plot and the highest 1000-seed weight and biological yield were 12.27g and 8.75 (t/ha) in 90 kg urea fertilizer along with Trooper sprayed plot whereas highest grain yield was 1.98 (t/ha) in 90 kg urea fertilizer along with Filia sprayed plot. The highest grain yield per plot increased (51.56%) in the fungicide Filia sprayed plot over control plot followed by Trooper (40.63%) and Nativo (31.25%) sprayed plot. Considering the importance of neck blast, losses was estimated separately and found difference where the highest yield loss was 1.15% in control (plain water) plot and lowest yield loss was 0.22% in Filia sprayed plot followed by Nativo (0.37%) and Trooper (0.31%) sprayed plot. Therefore, a conclusion has made from the research findings attempted to give suggestions that the three-spray of Filia with 15-day interval and 90 kg urea per hectare significantly reduced the blast disease of Jirakaribhog rice and increased higher yield significantly followed by Nativo and Trooper with minimum yield loss considering the neck blast.