Some wheat growers in western Nebraska experienced their best winter wheat yields ever in 2017 while others had some of their lowest yields. Moisture availability and disease incidence were key factors leading to either crop failure or success across western Nebraska wheat country.
As we move into the 2017/2018 winter wheat growing season, this special Wheat Focus Issue of CropWatch provides great information on things to consider.
West Central Nebraska
Some areas had good soil water at seeding for germination and plant establishment in fall 2016, while areas in southwest Nebraska had extremely dry hard soils at seeding time (Figure 1), which resulted in weak and poor stands. In some instances, the extremely dry conditions at planting led producers to slightly work the soil in order to be able to get the crop in the ground.
Despite dry conditions in the fall, many areas had timely precipitation in adequate amounts in the spring, which made high yields possible. In some instances, high yields led to lower protein content in the grain, similar to what was observed in high yield areas in 2016. (See related CropWatch article.).
Stripe rust was observed during the last week of May and first week of June as the winter wheat crop reached the flag leaf stage (Figure 2). Producers who sprayed a fungicide to protect the flag leaf observed a return on the investment.
Nebraska Panhandle
In the Panhandle, some growers had record yields while others suffered a complete loss due to disease. Most wheat was seeded into good moisture in the fall, leading to rapid emergence and good establishment. This would typically be good news for wheat yields, but the long warm fall enabled diseases to become established.
The lowest yields in the Panhandle occurred where the crop was devastated by the disease wheat streak mosaic. Most years this is only a problem if volunteer wheat was not properly controlled in fields where there was a pre-harvest hail event prior to planting. However, because of the unusual warm and long fall, the wheat curl mite that serves as a vector of the disease was active into November. Field surveys conducted in the fall of 2016 showed the presence of the disease in many parts of the Panhandle (See related CropWatch article..) Early seeding and planting next to corn that was still green also contributed to the severity of the disease.
Figure 1. The Sept. 13, 2016 Drought Monitor for Nebraska shows abnormally dry conditions for areas of southwest Nebraska at winter wheat planting time. (Source: US Drought Monitor)Figure 2. Stripe rust in winter wheat. Photo taken in North Platte on June 05, 2017.
Lessons Learned and Possible Implications for 2018
Unlike previous years (2015, 2016), stripe rust was not as widespread or damaging. The disease was present in most fields but did not progress much and many producers were proactive with fungicide applications. Other diseases were mainly kept under control with good management and fungicide applications.
Growers saw protein levels that were increased over the lows observed in 2016. Lower yields, lower incidence of stripe rust, and additional nitrogen were likely the primary reasons. The general rule is to have 1.5 to 2.5 pounds of nitrogen available per bushel of wheat to obtain optimal yields and good protein levels. (See Fertilizing Winter Wheat). The most challenging thing for wheat producers is to properly estimate their yield potential and ensure adequate fertility to maximize yield and protein. (For three methods for estimating wheat yield, see Estimating Winter Wheat Grain Yields, G1429.)
