4 Reasons to Scout Your Winter Wheat Crop at Green Up

When a baby wakes up from its nap, it suddenly needs everything all at once. Such is the case with winter wheat breaking dormancy.


There are four reasons why you should scout your fields at this time.


1. Your crop needs adequate nutrients

Top dressing nitrogen (N) when wheat breaks dormancy will stimulate tillers and help drive yield potential. A moderate amount of N should be applied at Feekes Growth Stages (FGS) 4 to 5 if stands are near 30 plants/sq. ft. at green up, but increase the N rate for stands that have fewer than 25 plants per sq. ft.


N can be applied as a solid or a liquid, but the crop needs to take it in by jointing to impact yield potential. If you’re in a drier climate, don’t wait too long to apply N; you’ll run the risk of not getting the fertilizer watered-in before the crop joints (FGS 6). It’s really hard to play catch-up after that. Later N applications may increase protein content of the grain, but have less effect on yield.


Green up is also one of the best times to submit tissue samples for NutriSolutions® analysis. Wheat is usually deficient in micronutrients like zinc (Z), copper (Cu) and manganese (Mg) at this point. So depending on the results, you may be able to give your crop a boost by applying MAX-IN® Ultra ZMB® or MAX-IN Copper micronutrients.


Ascend® plant growth regulator (PGR) can also be applied in a mix with MAX-IN Copper or MAX-IN Ultra ZMB. It doesn’t necessarily speed growth, but it can improve yield potential by helping build thicker stems and bigger root systems.


Spring is also a great time to apply a PGR like Palisade® EC PGR if you’re concerned about lodging. Palisade EC can help improve standability by shortening some wheat varieties by as much as 6 or 7 inches and developing a thicker stem without sacrificing yield potential. You can make a single treatment between FGS 4 to 7, or a split application with the first made at FGS 4 to 5 and the second made at FGS 7.


Research trials have shown an average yield increase of 6 bushels per acre when using Palisade EC in high lodging situations*, but be careful. Per product label instructions, yields can decrease if applied under drought or other stressful conditions.


2. Spring weed pressure is a concern

Grass weeds and summer annual broadleaf weeds love to pop up in spring. Two factors that to favor weed development are thin wheat stands and mild winters followed by early spring conditions. Depending on your location, grasses like annual bluegrass, annual ryegrass, cheat and downy brome could impact yield potential if left unchecked, as could the following weeds:

  • Kochia

  • Russian thistle

  • Canada thistle

  • Wild buckwheat

  • Dandelion

  • Purple deadnettle

  • Henbit  

  • Chickweed

  • Wild garlic

  • Mustards


Be sure to pay close attention to your crop’s growth stage before spraying and always review the product label. Most wheat herbicides are labeled for use at specific growth stages, and some of those have tight application windows, like between tillering and prior to jointing. So, depending on the herbicide you choose, you need to be very careful to not injure your crop.


Also make sure you consider your rotation when selecting herbicides. Several herbicides that can be applied on winter wheat have plant back restrictions that are longer than the three months that usually pass between spring applications and double crop soybean or winter canola planting.


Some farmers like to use a liquid N fertilizer solution as a carrier to apply herbicides and top-dress their crop in one pass as a way to save time and fuel costs. But once again, this requires caution to avoid crop injury. While several herbicide labels permit liquid N carriers, they require different rates and surfactants than when you use water as the carrier. Best to consult your local agronomist before taking this approach.


3. Leaf rust and stripe rust can reduce yield potential

Stripe rust isn’t as common as leaf rust, but it’s been a problem in recent years because the inoculum has blown in from the south and the conditions were ideal for disease development. Some winter wheat varieties carry good resistance to leaf rust, but not stripe rust. Farmers often justify taking a gamble by planting these varieties though, because although they lack stripe rust resistance, they’ve historically been strong yield performers. These varieties are good candidates for fungicide treatments in seasons when stripe rust is a concern.


Other diseases to be on the lookout for when scouting your fields include tan spot, Septoria leaf blotch, Stagonospora nodorum leaf blotch and powdery mildew.


Application timing is critical because the fungicides used on wheat have limited movement in the plant; they move with the xylem. In other words, they move up and out of the plant instead of back through the stem. So protection is limited if you spray too early, like when only half of the flag leaf is exposed. On the other hand, you allow the disease to cause significant yield loss if you wait too long to spray. In some cases, a fungicide application that’s made two or three days late can result in a loss of 10 to 20 bu/acre.


I always recommend spraying dual modes of action like a strobilurin and a triazole to treat your crop with both preventative and curative properties, as this can help improve control and manage against the potential for fungicide resistance. Just keep in mind that a “curative” fungicide doesn’t restore tissue, but rather kills the spores that have infected the leaf.


Consult your locally owned and operated WinField® United retailer when determining which fungicides to use and their respective application rates. They can help you prevent potential crop damage, since some fungicides can cause leaf burn. They can also suggest when tank-mixing partners like MAX-IN Ultra ZMB or MAX-IN Copper micronutrients could be of benefit.


4. Insects might pop up

Sometimes cut worm and green bug populations are high at green-up. They’re usually not a big problem at this point, but never take that for granted. Always go out and check your stands. If pest pressure is high, an application of Grizzly® Too or Yuma® 4E insecticides can usually get it under control.


* Application Rates: 0.09-0.114 lb ai/A (equivalent to 12-14.4 oz/A of Palisade® EC.) Number of trials = 11. Syngenta trials conducted in IL, KY, MD, MN, NY and OR.


© 2020 WinField United. Important: Before use always read and follow label instructions. Crop performance is dependent on several factors many of which are beyond the control of WinField United, including without limitation, soil type, pest pressures, agronomic practices, and weather conditions. Growers are encouraged to consider data from multiple locations, over multiple years, and be mindful of how such agronomic conditions could impact results. Ascend®, CROPLAN®, Grizzly®, MAX-IN®, NutriSolutions 360®, Warden®, WinField®, Yuma® and ZMB® are trademarks of WinField United. Genuity® and Roundup Ready® are registered trademarks of Monsanto. Palisade® is a registered trademark of Syngenta.