Want to product high wheat yields? Intensive spring management is the key.
Widespread heavy rains and an Easter blizzard across parts of Illinois haven’t made the last few weeks feel much like our traditional springs. But spring is here and there will be a lot to do as soon as field conditions allow. Despite our cool/cold wet weather, wheat fields have greened up and a lot of growth has occurred, with most of the crop in southern Illinois is at Feekes growth stage 4 – 5. Some early planted fields in the south are entering Feekes 6, where the first node is visible. Considerable differences in crop development have been observed in 40 to 50 miles, north to south, so as we gear up for spring planting, it is also important to pay close attention as the wheat crop rapidly enters the home stretch of its production cycle.
At this point, our first concern should be that nitrogen (N) is applied; including sulfur in this application should also be considered. For those who split the timing of nitrogen applications (usually Feekes 3 and 5 – 6), the second application should go on as soon as possible. Where a single nitrogen application was planned, most of those applications have probably already been applied or should be immediately.
While some N loss has likely occurred given the heavy rains most areas have encountered, the amount of potential loss is difficult to determine and probably not excessive in most situations, especially if nitrogen stabilizers or slow release dry fertilizers were used. However, this will depend on what product was used and the specific soil types in play.
If N losses are suspected it would be a good idea to discuss these factors with your retail supplier or agronomist to determine the best plan of action for your specific situation. Also, using crop color to judge likely N availability is not an accurate indicator, as the cold, saturated soils and lack of sunshine are the primary limiting factors to current crop development.
If it is suspected that excessive N loss occurred, a conservative approach to determining the supplemental N is recommended. Nitrogen losses aren’t uniform across fields and extra N applied to areas where losses have been minimal could result in lodging. Using a growth regulator to improve standability and reduce potential lodging would be a good idea in those situations.
A herbicide program to clean up winter annual weeds and ensure control of wild garlic (in So. IL) is necessary in growth stage 5 – 6. While scouting fields prior to application is always a good idea, this can be especially important with wheat as winter annual weed species and weed pressure vary widely according to tillage, previous crop and the herbicide program used on the previous crop.
The presence of herbicide resistant weeds, such as ALS resistant marestail, or grasses, such as Italian ryegrass, might also require a tank mix herbicide program to achieve the additional control that a standard single herbicide might not provide. There are several options to provide suitable control in about any situation, however, knowing what weeds are present BEFORE the herbicide application is made is the best way to determine the best plan of action. While assessing the need for a potential herbicide program, observing insects or early disease pressure might also influence the addition of an early fungicide or insecticide application at this timing as well.
Controlling disease is another very important part of maximizing high-yield wheat production. Feekes 8 – 9 (flag leaf) and Feekes 10.5.1 (Anthesis/Flowering) are the primary targets for fungicide application. Minor signs of foliar disease can usually be found in about any wheat field at the flag leaf stage. However, the extent of infection, timing and environmental factors in play vary with the season, so flag leaf fungicide applications aren’t always planned. Yet recent outbreaks of stripe rust have drawn more attention to protecting the flag leaf with fungicide and more producers are including this treatment as a part of their planned management strategy.
A fungicide application at Feekes 10.5.1 (flowering) is critical to control Fusarium head blight (scab), which tends to thrive in the warm, humid weather common at the time leading into wheat harvest. This disease can result in significant yield loss and drastically reduce grain quality. Fusarium produces the mycotoxin deoxynivalenol (DON), also known as vomitoxin.
In addition to yield and test weight reductions resulting from head scab, dockage is also assessed for DON levels which, if high enough, can result in rejection by the grain buyer. For this reason, it is very important to have a plan in place to ensure the right fungicide products are available and applied at the correct time. Harvesting early and not allowing wheat to totally dry down in the field is another related aspect of maintaining grain quality. Early harvest also allows double-crop soybeans to be planted earlier, which helps to maximize opportunities for both crops in the rotational system