In periods of pervasive wet and rainy weather, growers must be prepared for the possible ravages of Phytophthora and Pythium infections. Phytophthora fungi are commonly known as ‘water molds.’ But despite the innocuous name, they can be some of the most devastating plant pathogens known to man. In the mid-19th century, more than one million… 
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With the great majority of diseases afflicting crops, we are told to pay very close attention to moisture on flowers, fruit, and shoots, as well as moisture in the soil. This is because it’s understood that most disease organisms thrive under wet or rainy conditions. This seems logical, after all. Fungi, for instance, require a… 
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The primary concerns for rose growers as fall transitions to winter should be: Minimizing the carryover of inoculum—spores and fragments of fungal pathogens which can cause disease the following spring; Reducing populations of nematodes and other soil-borne disease pressures to create ideal growing conditions for root flush in January and February; and Maintaining rich soil… 
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Illustrations by the author, Dr. Thomas T. Yamashita (except where noted otherwise) Farmers and advisors frequently make the statement that healthy plants appear to tolerate or resist disease better than unhealthy plants. A skeptic might counter by saying that the plant is unhealthy because of disease, or the plant is healthy because it is free… 
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