Mild winter affected wheat disease development
Warm fall, winter, and spring temperatures can increase the prevalence, incidence, and severity of wheat virus diseases by favoring the survival and reproduction of both the viruses and their vectors. They also lengthen the period during which the viruses can damage the wheat crop.
This was the case in 2012 when wheat streak mosaic and barley yellow dwarf were detected in most fields surveyed, with some fields showing very severe symptoms (Figure 5). Wheat soilborne mosaic (Figure 6) was also observed at higher than normal levels of severity due to the warm fall and winter temperatures.
2012 Conditions Lead to Increase in Wheat Diseases
In conclusion, the potential for more disease and therefore greater yield loss is increased during a growing season that follows a warm winter; however, the extent of disease prevalence, incidence, and severity largely depends on environmental conditions, especially moisture. In the 2012 growing season, dry conditions slowed down or prevented the development of some fungal diseases. Despite the dry conditions, the early onset of disease due to above normal winter and spring temperatures and intermittent periods of wet weather are likely to result in greater winter wheat yield loss in 2012 than in a normal year. Some farmers have baled their wheat into hay or plowed it under in order to plant an alternative crop.