. Fig. 62. — Black-rot as it shows on the leaves. After Anderson. is mildewed soon ceases growth and falls, or develops ir- regularly and fails to ripen. The mildew fungus is strictly superficial and may be rubbed off, leaving a discolored spot. In late stages perithecia may be recognized as very small black bodies, about mm. in diameter, lying within the diseased areas. The disease develops in most destructive form in shaded, damp, poorly ventilated situations. Rain and fogs favor it, while very dry weather inhibits it. The American vines are less susceptible than the European varie
. Fig. 62. — Black-rot as it shows on the leaves. After Anderson. is mildewed soon ceases growth and falls, or develops ir- regularly and fails to ripen. The mildew fungus is strictly superficial and may be rubbed off, leaving a discolored spot. In late stages perithecia may be recognized as very small black bodies, about mm. in diameter, lying within the diseased areas. The disease develops in most destructive form in shaded, damp, poorly ventilated situations. Rain and fogs favor it, while very dry weather inhibits it. The American vines are less susceptible than the European varieties.
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Keywords: ., bookauthorstevensf, bookcentury1900, bookdecade1920, bookyear1921
