PGRFA

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The Disease:  WHITE TIP
Pathogen:
Aphelenchoides besseyi Christie

Etymology: from aphelen, simple; enchos, spear; and after Besseyi, a scientist
Disease:
The disease is known in most of the world's rice-growing areas. Yield loss depends on infestation level and other factors such as climate, variety, and agronomic practices (Bridge et al 1990).
Symptoms:
Leaf tips first turn white, from the tip and extending downward 3-5 cm. Infected plants lose vigor and are stunted. The flag leaf twists, affecting panicle emergence. Small panicles are partially exserted, the uppermost part remains sterile and lacks apikelets. In severely infected plants, panicles are affected. Infected grains are sometimes distorted. Yoshii and Yamamoto (1950) note that not all infected plants or tillers exhibit symptoms. Tolerant varieties are sometimes symptomatic while harboring the pests.

In white tip caused by insect damage, leaves also show perforations.

Appearance:

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Last Updated on Wednesday, 15 April 2009 08:26