. Diseases of economic plants. Plant diseases. 258 Diseases of Economic Plants prophylaxis are discussed under damping-off, p. 19. Seed beds known to be diseased should be avoided unless previously disinfected. Drop ^^^ {Sclerotinia liber- tiana). — Damping-off due to Sclerotinia is reported as a common trouble in seed beds. The injury to the plant is similar to that of the usual damping-off while the fungvis presents the charac- ters described under lettuce- drop. Young plants are killed; older plants may sur- vive, and if set in the field, develop poorlv. Mosaic. ^^- ^'^ — Wher- ever tobacco
. Diseases of economic plants. Plant diseases. 258 Diseases of Economic Plants prophylaxis are discussed under damping-off, p. 19. Seed beds known to be diseased should be avoided unless previously disinfected. Drop ^^^ {Sclerotinia liber- tiana). — Damping-off due to Sclerotinia is reported as a common trouble in seed beds. The injury to the plant is similar to that of the usual damping-off while the fungvis presents the charac- ters described under lettuce- drop. Young plants are killed; older plants may sur- vive, and if set in the field, develop poorlv. Mosaic. ^^- ^'^ — Wher- ever tobacco is grown the mosaic is very widely dis- tributed and destructive. Depreciation of $50,000 in quality was attributed to it in Ohio in 1905. It pro- duces a mottled appearance of the leaves due to varia- tion in texture and green- ness ; parts of the leaf show- ing full green and normal thickness, other spots pale oi- yellowish green, and thin. Accompanying these signs are distortions due to un- equal growth, wrinkled or curled leaves, and leaves of one-sided growth. Slightly affected leaves are depreciated in value; badly diseased leaves are Fig. 141. — Tobacco leaf showing leaf-spot. After Conn. Agr. Exp. 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, bookdecade1920, bookyear1921
