. Diseases of economic plants . Plant diseases. 378 DISEASES OF ECONOMIC PLANTS visible from both sides. They are about 1-2 mm. in di- ameter, and are not sharply bordered, but shade off grad- ually into the surrounding tissue. With a hand lens very small, spore-bearing organs may be seen in the centers of the older spots, first as shiny amber-colored elevations. These elevations soon crack open and expose very 12 3 1 Fig. 162.—Four alfalfa leaf spots; 1, ascochytose ; 2, pseudopezizose ; 3, cercos- porose; 4, stagonosporose. After Stewart and others. disk or cup shaped sporiferous bod
. Diseases of economic plants . Plant diseases. 378 DISEASES OF ECONOMIC PLANTS visible from both sides. They are about 1-2 mm. in di- ameter, and are not sharply bordered, but shade off grad- ually into the surrounding tissue. With a hand lens very small, spore-bearing organs may be seen in the centers of the older spots, first as shiny amber-colored elevations. These elevations soon crack open and expose very 12 3 1 Fig. 162.—Four alfalfa leaf spots; 1, ascochytose ; 2, pseudopezizose ; 3, cercos- porose; 4, stagonosporose. After Stewart and others. disk or cup shaped sporiferous bodies, which remain sur- rounded by portions of the ruptured epidermis. Badly diseased leaves usually turn yellow and fall off. Spots upon the stems show the same general character as those upon the leaves. The lower leaves, and the leaves of older plants, are most subject to the leaf spot. Plants late in the season, as of the second and third cuttings, suffer much more than earlier in the season. These crops, especially if allowed to stand a little too long before cutting in a dry season, may be badly. 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 Stevens, Frank Lincoln, 1871-1934; Hall, John Galentine, 1870-. New York : Macmillan
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Keywords: ., bookauthorstevensf, bookcentury1900, bookdecade1910, bookyear1910
