Plant Specific Mildews
Hop Downy Mildew (caused by Pseudoperonospora humuli) is specific to hops (Humulus lupulus). The disease is the single most devastating disease in Western United States hopyards, since the microbe thrives in moist climates. Infected young hop bines become stunted with thickened clusters of pale curled leaves. These spikes have a silvery upper surface, while the undersides of leaves become blackened with spores. These dwarfed spikes are called "basal spikes". 'Lateral' or 'terminal' spikes occur further up the vine. An entire hop crop could be devastated in only a few days.
Similarly, cucurbit downy mildew (caused by Pseudoperonospora cubensis) is specific to cucurbits (e.g., cantaloupe (Cucumis melo), cucumber (Cucumis sativus), pumpkin, squash, watermelon (Citrullus lanatus) and other members of the Cucurbitaceae/gourd family). The disease is one of the most important diseases of cucurbits worldwide.
Read more about this topic: Downy Mildew
Famous quotes containing the words plant and/or specific:
“The mode of clearing and planting is to fell the trees, and burn once what will burn, then cut them up into suitable lengths, roll into heaps, and burn again; then, with a hoe, plant potatoes where you can come at the ground between the stumps and charred logs; for a first crop the ashes suffice for manure, and no hoeing being necessary the first year. In the fall, cut, roll, and burn again, and so on, till the land is cleared; and soon it is ready for grain, and to be laid down.”
—Henry David Thoreau (1817–1862)
“No more distressing moment can ever face a British government than that which requires it to come to a hard, fast and specific decision.”
—Barbara Tuchman (1912–1989)