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Make Your First Pass On Winter Wheat The Right One
KYLE LILLY
SPRINGERTON, ILL.
Winter wheat establishment is essential for winter survival and early spring vigor, and the first foliar pass provides a good opportunity to proactively improve early growth. This article will explain limiting factors for early growth and will offer a solution to get winter wheat off to a good start.
There are several limiting factors for early season growth:
Weather Stress
Early winter wheat weather stresses include cool temperatures and moisture extremes. These stresses can reduce germination, stand establishment, and early seedling growth. Instead of building biomass and proteins, plants conserve metabolic energy for defense. Plant leaves shrivel under low water stress in order to limit water losses. Photosynthesis also decreases during excess moisture conditions because of reduced leaf area and limited metabolism.
Weed Competition & Chemical Stress
Weed management is essential to achieve optimum yields, but foliar applied herbicides can often cause crop stress. Many problem weeds for winter wheat establish in the fall, such as wild mustard, field pennycress, and sheperd’s purse. A foliar postemergent herbicide can be effective in controlling winter annual weeds if fall air temperatures are mild and weeds are still actively growing. Control of weed pressure may help with stand establishment and will certainly reduce the weed seed bank. However, many herbicides can stress the wheat crop and “stunt” growth for a period of time while the plant recovers from oxidative stress.
Nutrient Uptake
Winter wheat nutrient uptake is critical to establish a substantial root system that will in turn have a direct influence on number of tillers and eventually grain yield. At this timing, nutrient needs are low but deficiencies can severely limit early growth. While most nitrogen (N) is supplied at green-up in the spring, small amounts of N are needed at planting. Phosphorus (P) and potassium (K) rates are determined by a soil test and need to be applied at planting. Sulfur (S) is a key secondary nutrient in winter wheat since it is directly involved in N uptake and protein synthesis. Magnesium (Mg) is a major component of chlorophyll and also helps with N uptake. Manganese (Mn) and copper (Cu) are two micronutrients worth noting because they improve chlorophyll activity, cell wall strength, and N assimilation.
Biostimulants to Reduce Stress and Improve Nutrient Uptake
Plant biostimulants contain substance(s) and/or micro-organisms whose function, when applied to plants or the root zone, is to stimulate natural processes to enhance crop production. Research from our group and others has shown that biostimulant applications on winter wheat improve root growth, nutrient uptake, and the ability of the plant to handle stress. Fertiactyl GZ, an in-furrow and foliar applied biostimulant, is a flagship product in this emerging market. The product works by supplying a proprietary complex of plant extracts, organic acids, and mineral nutrients to reduce stress, improve stand establishment and promote early root growth.
One of the compounds in Fertiactyl GZ is called glycine betaine. Glycine betaine is an osmolyte that protects plants from weather and chemical stress. For winter wheat, glycine betaine will reduce water stress by maintaining a constant turgor pressure in the plant cells. It essentially acts as a protective agent for enzymes and membrane activity. Glycine betaine reduces chemical stress (oxidative stress) from herbicides by detoxifying the plants’ metabolic system.
Fertiactyl GZ also improves nutrient uptake and root growth with zeatin and organic acids. Zeatin interacts with plant growth hormones to build roots, especially fine root hairs. Fine root hairs have high surface areas, which allow plants to take up more water and nutrients. Organic acids, including humics and fulvics, increase nutrient uptake and microbial activity in the soil by chelating nutrients and providing carbon for microbes. Growers typically notice improved root growth three to four weeks after the Fertiactyl GZ application. The relationship between roots and yield is clear, and this technology is another tool to help ensure your first pass on winter wheat is the right one. ∆
KYLE LILLY: CCA, CPSS, Production manager with Timac Agro
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