. Diseases of economic plants . Plant diseases. 29:^ DISEASES OF ECONOMIC PLANTS gradually extend in all directions, involving the whole root. Older spots, 2-5 cm. across, often break or crack irregulurlj' near the center. This deca}^ differs from the soft rot in that the spots are dry and hard and that it is present upon the roots before digging. With the hand lens very small, hairlike, black structures, 1 mm. high, are seen studding the centers of the diseased areas. These are the beaks of the pycnicha of the causal fungus. Upon young sprouts before they are set out tiie disease causes black
. Diseases of economic plants . Plant diseases. 29:^ DISEASES OF ECONOMIC PLANTS gradually extend in all directions, involving the whole root. Older spots, 2-5 cm. across, often break or crack irregulurlj' near the center. This deca}^ differs from the soft rot in that the spots are dry and hard and that it is present upon the roots before digging. With the hand lens very small, hairlike, black structures, 1 mm. high, are seen studding the centers of the diseased areas. These are the beaks of the pycnicha of the causal fungus. Upon young sprouts before they are set out tiie disease causes black, dead [)atchcs, esperially at the base of the shoot or even upon the young leaves. The wood of the stem may be bi-owiied. Such sprouts if set result in enfeebled plants with dis- eased roots. Tile fungus throws myriads of spores into the .soil. This disease tims falls under the general class of soil In addition to the suggestions given on page (i)i, es|)ecial precau- tion should i)e exercised to avoid sets already- alVeclcd. IJadly af- fected siioots are easy of rc'cognilion, but the closest scrutiny is needed to (aiil out those oiil\' sligiitly Fic. r27. — liliicU rot. of .sweet [Xitat >. 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
