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Potato haulm resistance to Phytophthora infestans
Author(s) -
LAPWOOD D. H.
Publication year - 1961
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1961.tb03666.x
Subject(s) - phytophthora infestans , blight , biology , resistance (ecology) , canopy , horticulture , fungus , crop , agronomy , botany
SUMMARY Reasons were sought for the difference in haulm resistance to potato blight ( Phytophthora infestans (Mont.) de Bary) of four potato varieties. Up‐to‐Date produced more foliage than King Edward, Majestic and Arran Viking and a denser canopy which prolonged periods of high relative humidities, and lowered mid‐day temperatures by a few degrees. When field conditions favoured infection, the fungus spread in all varieties, but most extensively in King Edward and least in Arran Viking. Infections developed first, mainly in the lower crop canopy, then the middle and finally in the upper canopy, with lesions on leaves and leaflets distributed similarly on all varieties. The fungus advanced at the same rate in leaf laminae of all the varieties, but not in petioles, which were girdled more rapidly in Up‐to‐Date and King Edward than in the other two and consequently led to the collapse of more leaves. Majestic and Arran Viking are more resistant than Up‐to‐Date and King Edward in the field, because their leaves are infected more slowly early in the blight attack and die more slowly after infection.