Pierce Paul, Steve Culman, Ed Lentz, Laura Lindsey, Harold Watters, CPAg/CCA
The state of the 2014 wheat crop is variable. Some stands look very good while others have several bare patches. Overall, wheat fields on well drained soils and planted shortly after the fly-free date are in good condition, while fields that were wet in the fall and planted late tend to be in poorer condition. In the northern and northwestern portions of the state, some plants have frost damage on the tips of the leaves. However, since the growing point was still below the ground (protected from the cold), plants in the affected fields will likely recover and grow normally. The damaged leaves will soon be replaced by new growth.
Cool conditions and an extended winter have caused the growth of the 2014 wheat crop to be behind what is considered to be normal in Ohio at this time of year. The current growth stage is between Feekes 4 and Feekes 6. However, the exact growth stage cannot be determined just by looking at the height of the crop from the road, since these relatively cool temperatures may have prevented some varieties from reaching the height that is expected when the crop is at Feekes GS 6. Remember, short-looking wheat does not mean that the crop is not developing and advancing through the different growth stages.
Growers who rely on the height of the crop as an indicator of crop development may miss Feekes GS 6, a critical growth stage for herbicide application and top-dressing. Do not relay on the height of the plants or calendar dates alone to make your management decisions. Walk fields, pull tillers from multiple places, remove the lower leaves, and examine these tillers for the presence of nodes. At Feekes 6, the first node is visible at the base of the stem, about an inch or so above the soil line. For pictures of wheat throughout the Feekes growth stages and a summary of appropriate pesticide/fertilizer management timing go to Managing Wheat by Growth Stage ( K. Wise, et al) at https://www.extension.purdue.edu/extmedia/ID/ID-422.pdf.
Nitrogen should be applied by Feekes 6 and no later than Feekes 7 (including the second part of split applications). Yield losses may occur if the first N application occurs after these stages. Adding extra N at this time to poor growing areas will most likely not correct or improve the problem and will only become an unnecessary input cost. At the current growth stage, additional tillers will not develop; therefore bare patches will not recover. A urease inhibitor (Agrotain) may be beneficial if applying urea during warm to hot temperatures under rapidly drying conditions, if the chance of rain is low for more than 48 hours.
Feekes 6 is still too early to be concerned about applying fungicides for foliar disease management. Septoria leaf blotch and powdery mildew are usually the first to show up, but current conditions have not been very favorable for either of these diseases. As a result, a foliar fungicide application at the current growth stage is unlikely to be beneficial. Results from our studies have shown that the greatest benefits from foliar fungicide applications were obtained when treatments were made between Feekes 8 (flag leaf emergence) and Feekes 10 (boot). This is largely because most of our major foliar diseases usually develop and reach the flag leaf after Feekes 8-9. Continue to scout fields for diseases over the next few weeks. If it continues to rain as temperatures increase, you may want to consider a fungicide application at Feekes 8, especially if the variety is susceptible.
Source : osu.edu