Nitrogen fertilization and severity of panicle blight caused by Burkholderia glumae Burk. in relation to yield of rice (Oryza sativa L.)
2007
Abdulkadil, O.H., Philippines Univ. Los Banos, College, Laguna (Philippines)
Panicle blight is a serious problem in some rice growing areas in Region 12 [Central Mindanao, Philippines], particularly in the province of North Cotabato. A field experiment was conducted at PhilRice Midsayap Experiment Station during the wet (May to Oct 2006) and dry (Nov 2006 to Apr 2007) seasons to evaluate the effect of different levels of nitrogen fertilization in the severity of panicle blight in Mestizo 1 hybrid (PSB Rc72H) and inbred rice (PSB Rc82) and to determine the effect panicle blight on the yield and yield components of rice. The study was laid out in 2x4x4 factorial experiment arrangement in strip-split plot design where factor A was the rice variety, factor B the nitrogen levels and factor C the time of inoculation to vary disease severity in three replications. Nitrogen fertilization significantly increased the severity of panicle blight in the wet season rice cropping. Percent disease severity increased drastically in rice plants applied with 90-150 kg N/ha (47.33-55.60%) during wet season but was insignificant during the dry season. Severity of panicle blight did not differ significantly whether rice plants were inoculated during booting stage, at 1/2 panicle exerted and at fully exerted panicle stage (55.25, 56.06 and 62.17%, respectively). Severity of panicle blight during the dry season ranged from 42.15 to 47.48%. Panicle blight significantly decreased the yield and yield components of both hybrid and inbred varities. The number of panicles per square meter, number of spikelets per panicle, % filled spiklets, 1000-grain weight, and grain yield significantly decreased in both wet and dry cropping seasons. Panicle blight infected hybrid and inbred varieties significantly reduced yield. High % yield reduction was observed in hybrid rice PSB Rc72H (37.11%) during the wet season, but was insignificant during the dry season.
显示更多 [+] 显示较少 [-]