. Diseases of field crops. Plant diseases. 14 California Agricultural Extension Service [Cir. 121 Alfalfa seriously affected with nematode should be plowed up and the land kept in a cultivated crop for at least three years with special care to completely kill out every plant of alfalfa. Yellow Leaf Blotch.—This is a leaf-spot disease caused by the fungus Pyrenopeziza medicaginis. It is distinguished from ordinary leaf spot, which is caused by a different fungus (p. 11), by the fact that the spots. Fig. 8.—Effects of stem nematode on alfalfa. are of a bright yellow or orange color, with little
. Diseases of field crops. Plant diseases. 14 California Agricultural Extension Service [Cir. 121 Alfalfa seriously affected with nematode should be plowed up and the land kept in a cultivated crop for at least three years with special care to completely kill out every plant of alfalfa. Yellow Leaf Blotch.—This is a leaf-spot disease caused by the fungus Pyrenopeziza medicaginis. It is distinguished from ordinary leaf spot, which is caused by a different fungus (p. 11), by the fact that the spots. Fig. 8.—Effects of stem nematode on alfalfa. are of a bright yellow or orange color, with little black dots, mostly on the undersides. The disease is not usually serious in California but may occasionally cause enough defoliation to lessen the crop. For control, see the following paragraph. Handling Alfalfa for Disease Control.—Generally speaking, in Cali- fornia, the foliage diseases of alfalfa are worst on the early crops before the end of the rainy season. After this cutting is disposed of, diseases like rust, leaf spot, and downy mildew usually disappear. When the stand becomes weakened by these or other diseases, the only treatment is to keep the plants growing as well as possible by good irrigation, cultiva-. 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 Smith, Ralph E. (Ralph Eliot), 1874-1953. Berkeley, Calif. : College of Agriculture, University of California
Size: 1299px × 1924px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionamerica, booksubjectplantdiseases
