Effects of row spacing in the rice blast disease attack

Abstract

In 1981/82, two trials were carried out with the following rice cultivars: Bluebelle, EEA 406, Caloro, Starbonnet, BR-IRGA 410 and Fanny. The objective was to study the effects of row spacing (10 cm, 20 cm and 30 cm) on the rice blast Pyricularia oryzae Cav. disease attack. One trial was conducted under lowland condition and the other one under upland condition. The results showed that the leaf blast symptoms decreased at 30 cm row spacing. The attacks had hifferences between cultivars according to susceptibility of each one. The panicle blast incidence was correlated with the leaf blast attack at vegetative growth stage. Low grades of blast disease were observed in the cultivars Bluebelle, Caloro and EEA 406. The cultivar Fanny (grade 9), BR-IRGA 410 (grade 3) and Starbonnet (grade 1) did not show any differences between 10 cm and 30 cm row spacing at panicle blast attack.