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The Cropwalker - Volume 2 Issue 16

Always read and follow label directions.

Crop Conditions

Winter wheat has gone from bad to worse in many fields. Optimistically, we will have 60% of planted wheat left at harvest. That would mean 500-550,000 acres to harvest. Wheat that was planted in September and early October is filling rows nicely, and, at first node in the earliest fields. Septoria is showing up on bottom leaves. It is a brown lesion with black pepper like dots (pycnidia) This disease shows up every year. We have never been able to get a yield advantage by spraying this early. Powdery mildew is also showing in some fields. Weeds - fields with a preharvest burn down or tillage before planting are clean. Rest of fields should be checked. You can spray for weeds when it is too wet to do anything else. Corn not really any planted. Do not switch hybrids yet unless you ordered longer maturities than suited to your area. Seed dealers are sitting on pins and needles hoping there will not be too much switching due to late planting. When working and planting consider working fields during the day to dry out faster, and plant at night, rather than the other way. Harder to see at night for planting, so need lots of lights.  Soybeans nothing planted. Burndowns will be one of the first things to happen. Forages some uneven stands due to winter kill.

Picture 1 - Septoria on lower leaves



Wet and cool continues across North America. The US puts out planting progress on Monday. As of April 29 about 15% of US corn is planted. This is similar to 2018. Ontario’s weather forecast suggests we might get on some land later this week.

Which Crop Should be Planted First?

When the first field dries, plant the crop that was intended there. Soybeans, corn forages, cereals; all yield best when planted early. Do not worry about the soil temperature. If you have a soil thermometer give it to some one to slow them down. And don’t be too concerned about the weather unless the forecast is in the next 2-4 hours and the satellites show it will hit you. Reality is, the weather patterns that come up the Ohio Valley are unpredictable. However, for cereals spring wheat yields are the most impacted by late planting followed by barley. Oats is less impacted than barley or spring wheat with a delay in planting. Probably not a good year to be spreading manure before you plant unless you really have to get manure storage space.

Switching Corn Hybrids?

Not yet. Not even close. For 3200 CHU areas the switch date is May 31, for 280—3200 CHU switch date is May 25th, for lower CHU areas switch date is May 15-20.

Adjusting corn population based on Planting Date?

I asked this question to a major seed supplier. They didn’t really have data on yield by planting date by corn population. The conclusion we both came to, was that yield environment plays a bigger factor into which corn population should be used, than the calendar. Corn populations should be based upon that field or management areas long term yield potential, not planting date.

Initial winter wheat walks – Herbicide Selection

A couple of observations 1) See more of this every year, the growers that get a fall burndown on prior to having winter wheat established can delay spring herbicide applications or eliminate it entirely. It depends on your annual weed pressure. 2) If you did not do a fall burndown, winter wheat herbicide decisions are usually made on winter annual/perennial weeds. Don’t wait for the warm season annuals. Get the target weed when the ground conditions and timing is appropriate. Certain wheat herbicides have enough residual to not worry about the warm-season annuals. 3) There are leaf diseases such as Septoria and Powdery Mildew present, especially on early planted wheat. Some growers use cut rates of fungicide in this pass. My suggestion if you want to use a cut-rate, cut it out entirely. 7 days of control isn’t worth it. I am a proponent of two passes of fungicide on wheat, especially in areas where the straw is used for bedding. Depending on timing, it may not always give a significant yield bump relative to 1 pass of a properly timed application, but the straw is much nicer to work with.

What about VR Wheat Seed? Measure, Measure, Measure

I haven’t run into many Ontario growers or agronomy professionals doing variable rate work in cereals (especially winter wheat). If they are, it is typically a variable rate nitrogen script, or an on/off fungicide script. Based on 2019 wheat walks I have completed, the starting point should be seed rates in various parts of the field. If you currently have management zones in your field, check to see what the flat rate plant stands are in those areas. By doing this, you have a clue for VR wheat seeding rates this fall on the 2020 wheat fields. Expected benefits to doing this are: better weed control due to shading, even heading dates/field maturity, and in some cases, yield.

Nitrogen Rates in Winter Wheat

It’s April 29th, and I haven’t spread any N on my wheat yet? Should I still split it? From my travel’s wheat is starting to get hungry for nitrogen. What nitrogen the soil has released, in many instances has likely moved lower in the soil profile than the wheat can access with its current root system.

1.     You are growing soft red or soft white winter wheat, at this stage of the game, work is pilling up, if your equipment is capable of it, any wheat that has made it at this point is tillering or close to stem elongation, apply all nitrogen. Only reason to split would be if you had equipment limitations or had dry on your first pass (i.e. Urea/Potash/AMS) and have already bought liquid N for your section pass.

2.    You are growing hard red winter wheat. Stick to the two or three pass system. Usually the discount schedule of delivering low protein wheat is enough to continue with your previous program.

3.    Don’t wait for all areas to be 100%. In the wettest parts of the field yield has already been scarified significantly. Don’t make the 100 + bu areas suffer because you are waiting on a couple of spots that even today may only do 60 bu/ac. Think big picture on total bushels you are trying to protect.

Final Plant Stands – It’s time to count again

It was once commented we no longer had to do plant stands, the equipment had advanced enough that it would alert the operator when there was an issue. In the big scheme of things, populations checks should be of higher value than just a check for an equipment malfunction. Many growers are now running planters with section control and VR capability. As a result, they want to take advantage of it. Great! The question is, what is your final population? This is a factor of seed germination and in-field mortality. I’m guessing many could not tell me today what the mortality rate of their fields are before starting on this journey. The equipment can place the seed perfectly in the soil, but there will be differences between years, soil types and farms on mortality rates. Track this to fine tune your corn and soybean seed rates.

Rules of Thumb for N on spring cereals

Traction may vary by area, crop rotation, soil type and variety, but given the number of growers that haven’t grown spring cereals in a while, here are a few options on N rates. The further north your location, the higher the N rate you should consider. Consider a credit off of these values for manure and alfalfa.

Table 1 - Spring Cereal N/S recommendations


Get them done now. It is nice to have 72 hours between spraying glyphosate on perennial weeds before tillage. You may have to sacrifice some control to get corn/soybeans planted. Generally, if glyphosate is applied to annual weeds, including winter wheat, 1 hour before tillage, you should expect control. Too often growers wait to make sure all the weeds are up, and then having to deal with weed root balls, and partially dead weeds. Due to lateness of season and moist soil conditions do not count on tillage killing big perennial weeds. They will become cultivator escapes which are hard to kill in-crop. Seldom is there a problem from spraying too early. Often there is a problem by spraying too late.

What to do While Waiting?

1)    Make a list of the things you want to do in order. i.e. spray burndown at Clifford’s, work Johnson farm, and make sure everyone that you work with knows the plan. We may have a few hours to get some things done.

2)   Recheck crop plans for rates of herbicides and amount of each product to go into the tank. Check sprayer again so that all nozzles are working.

3)   Check corn planting depth. You want to plant corn at least 1 ½” deep. Last fall wheat fields planted too shallow did not survive.

4)   Give a field map to anyone else that does not know your farms, especially if you have a new farm. Give a copy to anyone that will be doing custom spreading or planting. Mark adjacent crops.

"Successful people focus their time on just a few priorities and obsess over doing things right." - Shane Parrish