. Diseases of field crops. Plant diseases. 6 California Agricultural Extension Service [Cir. 121 DISEASES BY CROPS ALFALFA* Bacterial Blight.—Brown, elongated, dead spots on the stems of al- falfa plants form the symptoms of this disease. The spots may be small and shallow or some of them large and deep enough to kill the stems. Similar but roundish spots may appear on the leaves. Bacterial blight,. Fig. 1.—A group of alfalfa plants affected with bacterial wilt. The dwarfed condition of the plants and the abnormality of the leaves are clearly evident when compared with the healthy plants shown
. Diseases of field crops. Plant diseases. 6 California Agricultural Extension Service [Cir. 121 DISEASES BY CROPS ALFALFA* Bacterial Blight.—Brown, elongated, dead spots on the stems of al- falfa plants form the symptoms of this disease. The spots may be small and shallow or some of them large and deep enough to kill the stems. Similar but roundish spots may appear on the leaves. Bacterial blight,. Fig. 1.—A group of alfalfa plants affected with bacterial wilt. The dwarfed condition of the plants and the abnormality of the leaves are clearly evident when compared with the healthy plants shown in the background. (Courtesy of F. R. Jones, United States Department of Agriculture; from Cir. 326.) caused by Phytomonas medicaginis, is common in California but attacks alfalfa only after freezing weather, so that the effects are not seen much except in the spring on the first cutting. After a cold winter, there may be a considerable loss in the alfalfa hay crop on account of this disease. The later cuttings are not affected. No method of control is known. 4 For further information, with descriptions and illustrations of diseases see: Madson, B. A. Alfalfa production. California Agr. Ext. Cir. 35:1-47. 3 figs. Ee- vised 1933. (Out of print.) Weimer, J. L., and B. A. Madson. Alfalfa diseases in California. California Agr. Exp. Sta. Cir. 326:1-19. 7 figs. 1932. (Out of print.) Brown, J. G., and R. B. Streets. Diseases of field crops in Arizona. Arizona Agr. Exp. Sta. Bui. 148:85-228. 58 figs. 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
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