Latent period to leaf blast in rice and its importance as a component of partial resistance

Abstract

In many pathosystems, a prolonged latent period is an important component of partial resistance. Latent period in rice to leaf blast was assessed in cultivars representing a fairly wide range of partial resistance under various conditions that are known to influence the expression of partial resistance considerably. The latent period was slightly more than four days and varied only little between treatments, with a maximum difference of only eight hours between cultivars. The very small differences in latent period were not associated with differences in partial resistance due to cultivar, nitrogen, or leaf age effects. It was concluded that the latent period is of no importance as a component of partial resistance to leaf blast.