Effects of Leaf and Stem Diseases on Yield and Quality of Alfalfa Forage 1
1969; Wiley; Volume: 9; Issue: 5 Linguagem: Inglês
10.2135/cropsci1969.0011183x000900050039x
ISSN1435-0653
AutoresW. G. Willis, D. L. Stuteville, E. L. Sorensen,
Tópico(s)Genetics and Plant Breeding
ResumoField plots of alfalfa, Medicago sativa L., sprayed weekly with Dithane M‐45 during the 1965 growing season to control leaf and stem diseases yielded 2.8 MT/ha (18%) more hay than did unsprayed plots (Average of four varieties in four cuttings). Disease control increased carotene content 21% (third cutting) and decreased stem defoliation 18%. Increases in annual forage yields in MT/ha, for sprayed over unsprayed plots, respectively, were ‘Cody’ 1.57 (8.8%), ‘Lahontan’ 3.47 (21.1%), ‘Ranger’ 3.11 (19.4%), and ‘Vernal’ 3.11 (26.9%). Phoma medicaginis and Leptosphaerulina briosiana were the major pathogens in the first and second cuttings. Their control increased yields of Cody 4%, Lahontan 14%, Ranger 19%, and Vernal 19% for the first two cuttings combined. Cercospora zebrina was the principal pathogen in the third and fourth cuttings. Control of C. zebrina increased yields of Cody 16%, Ranger 29%, Lahontan 30%, and Vernal 38% for the third and fourth cuttings combined. Corresponding increases in carotene content for the third cutting were 17, 20, 45, and 10%, respectively. Defoliation was reduced by spray treatments. Protein percentage was not affected.
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