. Diseases of economic plants. Plant diseases. 410 Diseases of Economic Plants In the seed bed the same disease may occur as damping- off. See p. 19. It seems that original infection always oc- curs in the seed bed, never in the open. Plants started in the open are not susceptible. If it is necessary to start them under glass, too thick sowing should be avoided, and they should be ventilated thoroughly. Soil that is known to be in- fested should not be used. The disease may be pre- vented by avoidance of the conditions that favor damp- ing-off. Yellows.''^^ â Growth is spindling and the shoots
. Diseases of economic plants. Plant diseases. 410 Diseases of Economic Plants In the seed bed the same disease may occur as damping- off. See p. 19. It seems that original infection always oc- curs in the seed bed, never in the open. Plants started in the open are not susceptible. If it is necessary to start them under glass, too thick sowing should be avoided, and they should be ventilated thoroughly. Soil that is known to be in- fested should not be used. The disease may be pre- vented by avoidance of the conditions that favor damp- ing-off. Yellows.''^^ â Growth is spindling and the shoots and leaves are yellow, but no death of affected parts occurs. In badly diseased plants no flowers, or only rudiments of such, develop upon the sick shoots. In other cases the flowers turn greenish-yellow, wholly or in part, with malformed floral parts producing little or no No parasites are present and the cause of the condition is unknown, but the striking similarity to peach yellows is obvious. The same disease affects the marguerite. Rust (Coleosporium soUdaginis (Schw.) Thuem.). ââ Orange-red sori, waxy in consistency, are produced in great numbers upon the leaves, which when badly affected curl, die, and thus bring about the death of the plant. Stem- rot (Corticium). â⢠See p. Fig. 216. â Rust on barberry. After 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
