Over the last two decades, however, growers have noticed yield declines throughout the valley. Agriculture specialists have identified an association between yield decline and disease symptoms such as stunting, vascular discoloration, late-season vine collapse, and root and crown rot, all symptoms of soilborne disease.
As causal agents for this problem had not been characterized, pathologists conducted two surveys. One to identify fungi associated with symptomatic squash tissue to establish the population present in diseased squash. The second identified fungi associated with squash randomly selected from 49 fields to establish the general fungal population associated with squash. The fungi collected from each field was compared to identify factors associated with the presence or absence of disease symptoms.
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