As Four State area farmers patiently wait for dry fields and soybean-stripping opportunities, prime wheat planting dates slip slowly by. At Mid-West Fertilizer’s Wheat Preplant workshop, Winfield agronomist Andrew Schmidt encouraged producers to use the wet weather period to develop a foolproof fall wheat plan.
Fall Wheat Nutrition
“Your best yield will come from best management in the fall — time and time again,” Schmidt said. “Wheat is a crop that — if you manage it right — rewards you in the end.”
Of the three main yield components for wheat — the number of heads, number of kernels per head and kernel weight — the number of heads is the factor most determined by fall management. For Schmidt, the number of wheat heads per field starts with plant establishment and plant establishment starts with field fertility.
“Getting three to four tillers per plant is my main goal,” Schmidt said. “What drives tiller establishment is fertility — particularly nitrogen, phosphorus and zinc.”
Of the three key ingredients for wheat establishment, zinc is often the most important and overlooked.
“Wheat actually removes more zinc than any other crop we work with,” Schmidt said. “It is very important for what we are going to go through in the next 90 days as far as tiller development and root development.”
One key factor in nutrient utilization is root uptake distance. For example, with the presence of water in the soil, roots can uptake nitrogen as far as 20 millimeters away but can only uptake zinc as far as 1 millimeter away, making zinc difficult for roots to access.
Making zinc abundant and accessible to plants can affect wheat quality as well as yield and, ultimately, profitability.
“Zinc is essential for 10 percent of all of the protein production in that plant,” Schmidt said. “It’s an auxin-producing nutrient, helps regulate the consumption of sugar in the plant and when you have zinc in a starter situation in any crop, you’ll see bigger, wider leaves.”
Schmidt encouraged producers to avoid the cheaper, heavy metal laden zinc oxide in favor of either zinc sulfate or zinc lignosulfate. Zinc sulfate is a quality product with many benefits for wheat with a few downsides in its heaviness and tendency to quickly tie-up in the soil and become less available to plant roots. For better availability and an even distribution across the field, Schmidt suggested the lignosulfate variety.
“Lignosulfates are a product that contains humic acid and helps you have more ideal prill size to blend well with phosphorus and potassium applications,” Schmidt said. “With the kelation in the lignosulfate, it allows the zinc to stay available longer.”
Availability of nutrients is a key factor in overall soil health and Schmidt said phosphorus availability could be a factor to watch — especially if producers are facing a delayed planting.
“The drop from 70 degree soil temperature to 55 degree soil temperature drops phosphorus availability by almost 70 percent,” Schmidt said. “As we keep going down in our temperature, our availability goes down, so it goes back to concentration.”
Preplant Preparation and Planting
Quality wheat begins with a clean field. Evenly distributed residue and a weed-free environment for wheat establishment can make a big difference in overall crop success. Improper residue distribution can result in streaky, uneven wheat and planting into winter weeds can eliminate an entire wheat crop.
“Whatever program you’re working with, have a plan to understand that weed competition in the fall really determines tiller development,” Schmidt said. “We’ve got to make sure we start clean.”
Grassy weeds are a difficult barrier for wheat producers as they become increasingly more resistant to traditional control methods.
“If you have grassy weeds get established in wheat in the fall and try to kill them in the spring — good luck,” Schmidt said. “Grassy weeds like Italian ryegrass, downy brome and cheat, we need to have a plan this fall on that.”
Herbicides like Anthem, Flex and Zidua can be applied to wheat after spiking for residual control of grassy weeds, Schmidt said. Less resistance has been noted for these herbicides and they can provide control before other weed control methods, like 2, 4-D and dicamba can be applied.
“I avoid using growth regulators in the fall until it is fully tillered,” Schmidt said. “When you throw 2,4-D and dicamba on a wheat plant that is trying to develop tillers, they kind of get malformed.”
After field preparations, determining a planting date is the next step for producers. For most of southeast Kansas, optimal wheat planting dates will fall between Oct. 5 and Oct. 25.
“Right now is a really good time for optimal planting dates for good tiller growth,” Schmidt said. “Planting too early has potential for Hessian Flies or aphids that come out early and can transmit diseases.”
Late plantings will be a concern for producers due to field conditions. While Schmidt cautioned producers that late plantings could result in poor establishment or low tiller development, he also offered planting rate solutions should producers be forced to delay planting.
“Planting rate depends on planting date so as we move into later October and November, we need to start increasing our planting rate by about 10 percent per week,” Schmidt said.
Disease and Insect Concerns
Wheat seeds with impurities or foreign material can be a vehicle for wheat diseases, Schmidt said. Fusarium can impact fall seedlings if the seed is contaminated and planted untreated.
Loose smut, a disease causing black wheat heads at harvest, can also be controlled in the fall, Schmidt said. A seed treatment can control the disease and eliminate nay yield loss.
The two most impactful fall wheat diseases, Schmidt said, will potentially be loose smut and pythium under this season’s conditions.
“Pythium is a natural disease we see under cool, wet conditions in the fall,” Schmidt said. “With our conditions now, pythium has the potential to be a concern.”
Fall aphids and Hessian flies will be key concerns as well heading into fall wheat establishment. While aphids can be controlled with a seed treatment in the fall, the Hessian fly will need to be controlled with an insecticide.
Schmidt encouraged producers to be as vigilant with wheat disease and insect control in the fall as they would in the spring. Fall establishment is key for high yield potential in wheat, Schmidt said.
“To raise good wheat, you’ve got to protect that crop,” Schmidt said. “Keeping that factory, that plant, healthy throughout its life cycle will reward you with bushels at the end.”