. Diseases of economic plants. Plant diseases. Vegetable and Field Crops 233 and is, therefore, of greatest importance to growers of seed potatoes. Seed should be carefully selected, and then dis- infected. Leaf-roll ^^' ^^^ ^^^' ^^^' ^^^ (Phloem-necrosis) and Mosaic (Leaf-curl or Curly-dwarf), two closely related diseases of wide distribution, cause serious crop loss. In Bermuda, for exam- ple, the loss from leaf-roll is estimated to be well 50. Fig. 130. — Potato leaf-roll. After Orton. per cent of the crop. The two diseases, formerly regarded as three, are difficult to distinguish ac
. Diseases of economic plants. Plant diseases. Vegetable and Field Crops 233 and is, therefore, of greatest importance to growers of seed potatoes. Seed should be carefully selected, and then dis- infected. Leaf-roll ^^' ^^^ ^^^' ^^^' ^^^ (Phloem-necrosis) and Mosaic (Leaf-curl or Curly-dwarf), two closely related diseases of wide distribution, cause serious crop loss. In Bermuda, for exam- ple, the loss from leaf-roll is estimated to be well 50. Fig. 130. — Potato leaf-roll. After Orton. per cent of the crop. The two diseases, formerly regarded as three, are difficult to distinguish accurately without the use of the microscope, but in general in leaf-roll the segments of the lower leaves are pale, permanently rolled upward and rigid, the terminal segments becoming spoon-shaped; while in mosaic, generally, the leaf segments are distorted, the veins unduly prominent, and the blades mottled with light areas, and in severe cases the plants dwarfed by shortened inter- nodes, giving rise to the designation ''; Plants affected by either of these diseases show retarded tuber development and reduced 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- [from old catalog]; Hall, John Galentine, 1870- [from old catalog] joint author. New York, The Macmillan company
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Keywords: ., bookcentury1900, bookdecade1920, bookpublishernewyo, bookyear1921
