Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: August 5, 2005
Publication Date: November 6, 2005
Citation: Krupinsky, J.M., Tanaka, D.L., Merrill, S.D., Liebig, M.A., Hanson, J.D. 2005. Dynamic cropping systems for managing plant disease risks. Symposium--Dynamic Cropping Systems for Soil & Water Conservation. No. 102-2. IN: Annual Meeting Abstracts CD-ROM, Nov. 6-10, Salt Lake City, UT, ASA-CSSA-SSSA, Madison, WI. Technical Abstract: Crop diversification and crop sequencing can influence plant disease risks in cropping systems through crop selection and interruption of disease cycles. Leaf spot diseases, such as tan spot, caused by Pyrenophora tritici-repentis [Died.] Drechs. and stagonospora nodorum blotch, caused by Phaeosphaeria nodorum [E. Müller] Hedjaroude are present on hard red spring wheat (Triticum aestivum L.) in the northern Great Plains. No-till field research was conducted southwest of Mandan, ND to determine the influence of preceding crops and crop residues on leaf spot diseases of wheat under the semi-arid conditions of central North Dakota. Spring wheat was direct seeded (no till) in the crop residue of ten crops (buckwheat [Fagopyrum esculentum Moench], canola [Brassica napus L.], chickpea [Cicer arietinum L.], corn [Zea mays L.], dry pea [Pisum sativum L.], grain sorghum [Sorghum bicolor (L.) Moench], lentil [Lens culinaris Medik.], oil seed sunflower [Helianthus annuus L.], proso millet [Panicum miliaceum L.], and hard red spring wheat) at two sites. Soil residue coverage, measured with a transect technique after seeding spring wheat, indicated that crop sequences composed of spring wheat, proso millet, and grain sorghum had the highest soil residue coverage. Spring wheat was evaluated for severity of leaf spot diseases following various crop sequences. Differences among preceding crop sequence treatments were apparent. Spring wheat following crop sequences with alternative crops for one or two years had lower levels of disease severity compared to continuous wheat. The use of crop sequences with preceding alternative crops lower the risk for leaf spot diseases of spring wheat.