Sooty blotch and fly speck are the two most common “summer diseases” of apples in the Northeast; they are also problems on pears. Although caused by two different organisms, the diseases often occur together since both are confined to the fruit...

, but is not generally as damaging on these crops. Successful long-term production of peaches is seldom possible if the disease is not controlled....

Fire blight, caused by the bacterium Erwinia amylovora, is one of the most destructive diseases in apple and pear production. Fire blight can infect other members of the rose family including quince, juneberry, hawthorne, mountain...

into storage scab lesions after harvest. Disease Cycle and Causal Organism Apple scab is caused by the fungus Venturia inaequalis, which also is capable of infecting crabapple , hawthorn, mountain ash, and firethorn . Different but closely related Venturia...
at prevailing temperatures (table 1), growth from the germinated spore penetrates and infects these organs just beneath the outer cuticle. Typical lesions, each bearing tens of thousands of secondary or summer spores (conidia). appear about 9 to 17 days later...

.) Disease Cycle and Causal Organisms Phytophthora root and crown rots are caused by a group of related soilborne fungi in the genus Phytophthora. Some of these fungi are common inhabitants of agricultural soils, whereas others are introduced on contaminated...
favorable. Some rootstocks appear to be most susceptible to infection during the spring and autumn, which are also the periods of the year when soil temperatures are most favorable for zoospore production and activity. Rootstock susceptibility and fungus...