Path coefficient analysis on the effects of blast on rice growth, yield and yield components
1988
Torres, C.Q. | Teng, P.S. (International Rice Research Inst., Los Banos, Laguna (Philippines))
Two trials were conducted to determine the effects of blast on rice growth, yield and yield components. Different levels of epidemics were induced by covering some of the plots with plastic sheets at night, applying different amounts of inoculum, timing of inoculation, and spraying with tricyclazole. Tillers were sampled weekly to measure leaf blast severity, plant height and biomass. At harvest, panicle blast incidence was determined and yield components were measured. Different epidemic patterns were obtained in both trials. Path coefficient analysis showed that leaf blast has relatively stronger negative effect on plant height than on leaf, stem and panicle biomass. Panicle blast on the other hand, had a stronger effect on panicle biomass than leaf blast. Number of filled grain (NOFG) and 1000-grain-weight were the yield components almost equally affected by leaf blast. Percent unfilled grain % UG) was affected more by panicle blast than by leaf blast. The NOFG and % UG have the highest direct effect on yield loss in the first and second trials, respectively. Two equations that would predict yield loss (%) at any observed leaf blast severity (maximum) and panicle blast incidence were developed.
显示更多 [+] 显示较少 [-]