INTEGRATING RESISTANCE, BEST APPLICATION TIMING AND BEST FUNGICIDE DELIVERY TECHNIQUE FOR IMPROVED EFFICACY ON BARLEY, LANGDON, 2008

摘要

Fusarium head blight (FHB) has reduced small grain yield and affected crop quality in the Northern Plains region of North America since 1993 and many other wheat and barley production regions worldwide. Genetic resistance to infection and spread of FHB will need to be combined with other management strategies to reduce losses in the short term. Control by fungicides has been inconsistent. This variability is due to environment, cultivar resistance, pathogen virulence, fungicide application method, coverage and fungicide timing. In the United States producers have been limited to one application of fungicide at the extended head growth stage in barley. Two cultivars were used in the trials including "Tradition" and a North Dakota Experimental labeled"ND20448". No differences were determined for FHB incidence, severity, index, test weight and plump. Foliar leaf disease was greater on the "ND20448" as compared to "Tradition", but foliar disease pressure was low in 2008. A significant interaction foryield was measured between cultivar and timing. The yield of "Tradition" barley was increased when fungicide was applied at Feekes GS 10.3 as compared to the GS 10.5. An interaction was measured for DON concentration between the cultivar and timing and also between the orifice orientation and timing. Deoxynivalenol levels decreased when the fungicide was applied to both cultivars at GS 10.5 as compared to 10.3. Deoxynivalenol levels also decreased further on cultivar ND20448 by the application timing at GS 10.5+5 days. A vertical oriented nozzle was less effective than a nozzle angled 30 degrees downward from horizontal and forward in depositing spray solution, 0.2 versus 0.34.