. Minnesota plant diseases. Plant diseases. 2 74 Minnesota Plant Diseases. Though a very common fungus, it does not very often occur in sufficient amount or at the proper season to cause very ex- tensive damage and usually no preventive methods are deemed necessary. The ordinary sprays for the fungi with superficial mycelia would probably prove effective against this disease. (See also Fig. 52.) Powdery mildew of elms {U^icinula macrospora Peck). This mildew is not uncommon, though it cannot be said to be abun- dant throughout the state. It attacks only the young trees or saplings of elms. On
. Minnesota plant diseases. Plant diseases. 2 74 Minnesota Plant Diseases. Though a very common fungus, it does not very often occur in sufficient amount or at the proper season to cause very ex- tensive damage and usually no preventive methods are deemed necessary. The ordinary sprays for the fungi with superficial mycelia would probably prove effective against this disease. (See also Fig. 52.) Powdery mildew of elms {U^icinula macrospora Peck). This mildew is not uncommon, though it cannot be said to be abun- dant throughout the state. It attacks only the young trees or saplings of elms. On an affected tree the fungus is usually exceed- ingly abundant, covering many or most of the leaves with a very con- spicuous mildew. The latter attacks the leaves and oc- curs on the upper surface. White, circular patches of the superficial mycelium are formed and these may combine with neighboring ones to cover the entire leaf. These patches are con- spicuously white and dense and have a somewhat starchy appear- ance. The win- ter-spore fruiting Fio. 135.—Powdery mildew of elms (Uncinula macrospora), hnrlipc arp or>nrA on an elm leaf. The exceedingly minute black spots are '-'>-"-iico die spuic- sac-capsules of the fungus. The fungus mycelial threads Sac-Cansule^ and form in spots which are very conspicuous. Original. r "'"-* ctliu. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Freeman, Edward Monroe, 1875-. Saint Paul, Minn.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectplantdi, bookyear1905
