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2 Fungal diseases. 3 Nematodes, parasitic. 4 Viral diseases. 5 Viroid diseases. 6 Suspected viral- and viroid-like diseases. ... Viral diseases; Apple chlorotic leafspot
Apple scab is a common disease of plants in the rose family that is caused by the ascomycete fungus Venturia inaequalis. [1] While this disease affects several plant genera, including Sorbus, Cotoneaster, and Pyrus, it is most commonly associated with the infection of Malus trees, including species of flowering crabapple, as well as cultivated apple.
Apple trees can recognize invading pathogens and mount a defense. [4] Often, the plant may be able to resist the pathogen, even though it has no genetic resistance to same. Apple trees seem to have a weak defense to A. mali , base on the fact that no survivors if leaves has been infected.
The infection cycle begins in the springtime, when suitable temperatures and moisture promote the release of V. inaequalis ascospores. These spores rise into the air and land on the surface of a susceptible tree, where they germinate and form a germ tube that can directly penetrate the plant's waxy cuticle.
Additionally, pruning and disposing of galls from infected cedar trees would reduce sources of inoculum for infection of apple trees, however this would likely be time consuming and uneconomical. [6] For those doing bonsai, it is common to have the trees within feet of each other and on the central eastern seaboard of the United States, eastern ...
It can prevent damaged tree limbs from harming other branches and increase airflow between branches, reducing potential fungal diseases, says Eric North, program manager of urban forestry and ISA ...
Age factors into P. expansum infection, in that overripe or mature fruits are most susceptible to infection, while those picked underripe are less likely to become infected. In apples, the colors of the lesions may vary with variety, from lighter-brown on green and yellow apple varieties to dark-brown on the deeper-red and other darker-color ...
Rosellinia necatrix is a fungal plant pathogen infecting several hosts including apples, apricots, avocados, cassava, strawberries, pears, hop. citruses and Narcissus , [ 1 ] causing white root rot. References