Severity and incidence of Rice yellow mottle Sobemovirus on rice yield

Abstract

Screenhouse and field experiments were conducted to evaluate the severity and incidence of Rice yellow mottle Sobemovirus (RYMV) on paddy yield of 14 rice cultivars. The screenhouse experiment was arranged as a completely randomized design while the field experiment was laid out in a randomized complete block design. Each experiment was replicated three times. The test cultivars were inoculated with the virus at 3 weeks after sowing. Analysis of variance indicated that the virus had significant effect on all the parameters (disease severity, disease incidence and paddy yield) assessed. The screenhouse results showed that disease severity ranged from 54.3 to 64.4 %, RYMV incidence varied from 73.4 to 100 % and paddy yield per plant was in the range of 0.8 to 2.3 g. On the other hand, the results of the field experiment indicated that disease severity, incidence and paddy yield ranged from 44.4 to 64.3 %, 66.1 to 100 % and 1.4 to 3.2 t ha-1, respectively.