Rice Varietal Responses to Stemborer Under Natural Conditions

Abstract

Test varieties of rice which showed low levels of stemborer infestatio in natural screening tests at a number of research stations, were intensively studied and compared with recommended Thai varieties and introduced varieties reported to be resistant to stemborer. The line SPRLR77210-KSR-2-9 was outstanding both in relation to its relative resistance to stemborer damage and yield when compared with the currently recommended variety RD 9; it outyielded RD 9 by an average of 26 percent. Under conditions of severe stemborer infestation the yield from SPR:R77210-KSR-2-9 was 4.6 times greater than from the variety RD 7; this line also showed resistance KSR-2-9 has qualities of resistance to stem borer that could be used in both areas and seasons of a normally high incidence of stemborer damage.