Reaction of some rice cultivars to the white tip nematode, Aphelenchoides besseyi,under field conditions in the Thrace region of Turkey

Abstract

Abstract: The objective of this study was to evaluate the reactions of 41 rice cultivars to Aphelenchoides besseyi under field conditions in 2012 at the Thrace Agricultural Research Institute. The experiments were conducted as split plots in a randomized complete block design with 3 replications. An infected plot and an uninfected control plot were the main plots; the cultivars were subplots. As a sign of nematode damage, white tip infection ratio on the rice caused by nematodes was determined in the experiments, and the losses in yield components for the rice cultivars were calculated. There were decreases both in the grain number per panicle (by 38.3%) and in the panicle weight (by 49.7%) in the infected plot with symptoms of white tip nematode. The Ribe cultivar had the highest yield losses due to nematode damage, with 52.1%. The Asahi cultivar, which is a resistant control, had the lowest yield losses with 7.8%. There was a significant positive correlation (r = 0.5068) between the average chlorophyll values (SPAD) in the flag leaf and average white tip ratio (%). Although there was a significant positive correlation (r = 0.7571) between the yield loss and the white tip infection ratio in all cultivars, no significant relation was found between the yield loss and nematode density.