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ARS Home » Plains Area » Mandan, North Dakota » Northern Great Plains Research Laboratory » Research » Publications at this Location » Publication #145660
Title: LEAF SPOT DISEASES OF BARLEY AND SPRING WHEAT AS INFLUENCED BY PREVIOUS CROPS

Author
item Krupinsky, Joseph
item Tanaka, Donald
item LARES, M - UNIV OF MARY,BISMARCK

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/30/2003
Publication Date: 1/31/2004
Citation: Krupinsky, J.M., Tanaka, D.L., Lares, M.T. 2004. Leaf spot diseases of barley and spring wheat as influenced by previous crops. Agron. J. 96:259-266.

Interpretive Summary: Management practices such as using different crops and crop sequences (the order in which crops are planted) can influence plant disease risk. Ten crops, barley, canola, crambe, dry bean, dry pea, flax, safflower, soybean, sunflower, and spring wheat, were planted in crop residue from the previous year to evaluate crop sequencing effects. The objective of this research was to determine the effect of ten preceding crops on barley leaf spot diseases. The most common leaf spot diseases on barley were net blotch, followed by stagonospora avenae leaf blotch, septoria speckled leaf blotch and spot blotch. Diseases started first on the lower leaves and moved up the plant. Differences in the amount of leaf spot diseases on barley were evident for thirteen of fifteen evaluations over two years. This indicated that the previous crop influenced leaf spot diseases of barley. Results indicate that the risk for leaf spot disease on barley would be lower following wheat, crambe, canola and dry peas compared to barley after barley and similar to barley after barley following dry bean, flax and soybean.

Technical Abstract: Crop diversification and sequencing can influence plant disease risk in cropping systems. Ten diverse crops, barley, canola, crambe, dry bean, dry pea, flax, safflower, soybean, sunflower, and spring wheat, were planted in the crop residue of the same ten crops from a previous year to evaluate crop sequencing effects. The objective of this research was to determine the effect of ten previous crops on barley leaf spot diseases. The most common leaf spot diseases were net blotch (Drechslera teres), followed by stagonospora avenae leaf blotch (Stagonospora avenae f. sp. triticea), septoria speckled leaf blotch (Septoria passerinii) and spot blotch (Bipolaris sorokiniana). Diseases developed first on the lower leaves and progressed up the plant. Differences in the severity of leaf spot diseases on barley were evident for ten of eleven evaluations in 1999 and for three of four evaluations in 2000. Differences in the severity of leaf spot diseases among treatments indicate that the previous crop influenced leaf spot diseases of barley. Several crop residue treatments had less disease than the barley-after-barley treatment. These results would indicate that risk for leaf spot disease on barley would be lower following wheat, crambe, canola and dry pea compared to barley after barley and similar to barley after barley following dry bean, flax and soybean. The barley-after-barley treatment had the lowest yield.