Early season fungicides
Multiple research projects have been conducted by Dr. Kelly Turkington of Agriculture and Agri-Food Canada (AAFC) on early season fungicide. Results showed half or full rate fungicide applications at herbicide timing and half rate flag leaf fungicide applications on barley did not improve crop productivity, or reduce disease as compared to full rate at flag leaf. Although crop stages for herbicide timing fungicide application treatments varied between experiments, the take away was the same each time. It should also be noted that delaying herbicide timing to get a later fungicide timing reduced yield due to early season weed interference.
As for wheat, early season fungicide research is limited but Dr. Kelly Turkington expects results to be similar or even less beneficial, as the leaves that provide most of the yield for wheat emerge later than that of barley. A research review from the northern Great Plains in the United States show limited and non-economical response to early season fungicide to wheat in low rainfall areas. To further understand early fungicide effects on wheat yields, quality, and disease control, the Alberta Wheat Commission funded a research project led by researcher Dr. Sheri Strydhorst of Alberta Agriculture and Forestry that will investigate where and when an early season fungicide may be beneficial.
In short, if you have a barley variety with a good disease package, you have a long rotation between barley crops and moisture is limited, you will be hard pressed to find benefit from early season fungicide applications.
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