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Title: EFFECT OF LEAF AGE AND NODAL POSITION ON LEAF RESISTANCE TO THE RICE BLAST PYRICULARIA GRISEA SACCARDO

Author
item YANG, Y - TEXAS A&M UNIV
item MAKELA, M - TEXAS A&M UNIV
item WILSON, L - TEXAS A&M UNIV
item Marchetti, Marco
item KRAUSZ, J - TEXAS A&M UNIV

Submitted to: Rice Technical Working Group Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 2/1/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The effect of leaf age and nodal position on leaf resistance to rice blast, Pyricularia grisea Saccardo, was studied by inoculating pot rice plants at each of six stages of rice growth. Blast pathogen race IC-17, isolate 92T107, and rice cultivar Rosemont were used in The study. Lesion density after full lesion appearance (no more new lesions) decreased exponentially with increasing leaf inoculation age, indicating an increase in blast resistance with leaf age. Lesion density was about The same from The 4th to 7th nodal position, but dropped sharply from The 7th to 11th nodal position. The flag leaf was The most resistant of all nodal positions. Leaf nodal position did not have an obvious effect on The frequency of lesion appearance. But with increasing leaf inoculation age, The appearance of individual lesions required a greater amount of time. Leaf inoculation age and nodal position did not significantly affect lesion size eand distribution of lesion size.