All posts by : rachel

Now that we have finally gotten rain I wanted to speak to you with a little clarity about disease management and winter wheat as we continue to develop.  I do not want to give the impression that I believe we are out of the woods on moisture needs. My main emphasis will be pathogens as it relates to weather.  I will also look at plant physiology and ultimately grain protein. 

First, looking south helps us predict rust outbreaks in Kansas.  Since this disease spreads via spores then we need favorable conditions to the south for the disease to proliferate.  Looking at the weather in the southern plains the fall and early spring has been very dry. As I have mentioned before environment is a crucial component of the disease triangle. In looking at points south and discussing with pathologists in OK and TX the indices of rust has been minimal as we would expect.  This in turn can and will have a direct impact on our rust pressure.  This is not to say there will be no rust it just means that the likelihood of widespread infection is minimized.  Understand that micro climates can play a role as well. Spore formation was not eliminated just decreased. If we have favorable environments such as this week, the disease can blow up.  Second, we continue to have more and more acres planted behind corn and milo stalks.  Fusarium head blight is becoming more and more of a problem as a result.  This disease does not happen until flowering. In this case the inoculum is here we just need a warm moist environment during flower for it to proliferate.  This is becoming a significant disease in the eastern half of the country where there is typically for more humidity during flower.  Typically a delaying the treatment until closer to flower is more appropriate.  While we will be seeing heads soon we will need to manage pathogens as well.  Never assume that there will be no disease pressure.  My purpose here is not to sound an alarm just to educate on the realities of what we are dealing with this year.  Understand if this type of weather persists then we could have some localized disease pressure. If we go back to the previous pattern then not so much.                              

I will now talk about winter wheat and protein accumulation which is a product of the physiology of the wheat plant.  Nitrogen is a common element of both protein and amino acids in a plant.  It has been shown through research that delayed Nitrogen top dressing actually regulates gene expression related to N metabolism and protease synthesis in the flag leaf.  This in turn will result in more free amino acids being transferred to the endosperm and the kernel itself.  In a nutshell late applications of N can and will help unlock the genetic potential of the plant to accumulate more protein in the grain.  Normally applying late applications of nitrogen can and will result in some phytoxicity.  This is not acceptable if the flag leaf is emerged. Therefore, it is best to look at a safer product such as urea liquor (Chrome). Not only is Chrome a Urea Liquor but it so much more. This product also has Organic Acids, sugar and other compounds to ensure crop safety and optimal uptake. 

Our spring weather never ceases to amaze me.  The cold air this week was pretty significant.  We had two mornings that the temperatures dipped below 20F one being closer to 10 F.  That is cold regardless of the time of year.  Unfortunately with the cold air we only received wind no moisture.  We are now within a couple of weeks of irrigated corn being planted. I have seen a lot of sprinklers going over the past week on wheat and some pre water for spring crop.    I did measure some soil temps this weekend and found some no till fields 38 F at the 4” depth and some strip till at 40-43 F.  We need some more days like today to make the 25^th of April planting more of a reality.  The flip side of this when the weather warms we could see some of this dryland wheat starting to moisture stress quite rapidly.  The cooler temps have been helping us out in this aspect.   The calendar is telling us regardless it is time to get things done. I will now transition to this week’s info.        

 Wheat is developing less rapidly than I anticipated due to the colder temperatures. I am still seeing some fields approaching  Feekes 6.  I have had several questions this week in reference to the cold temperatures.    The photos below again illustrate both Feekes 5 and 6 which is where we are developmentally for the most part.   

The wheat resistance chart gives some general expectations in regard to the yield effect when crop is exposed to freezing temperatures. I will not make any assumptions here but, we need to understand the potential impact on yield.  I also attached the Mesonet weather data from the Colby weather station.  As you can see the temperatures did get quite cold on the mornings of the 13^th and 14^th.  While it did warm up rather quickly there were a few hours that the temperatures were below freezing.  We deal with this one time or another every spring as always, the severity will be dependent on the developmental stage. I will be assessing  the impact on some wheat fields later this week.   As we all know our wheat has been through a great deal to this point and will continue to do so if we remain in this dry cycle.  While we cannot control the weather we need to continue to focus on the things we can control to optimize yield.                                                                                     

The spring crop project is now in high gear.  I have heard of some corn being planted shortly on irrigation.  I wanted to circle back to biologicals since I am hearing more and more products and claims.  When hearing these claims remember to go back to the fundamentals of what we have discussed this winter.  This space is cluttered with a lot of false claims and lack of the fundamental knowledge of the process. I will not go into a long decertation just understand this is something that has been happening in our soils for some time.  We have to resist the temptation to attempt to treat this much like we do with basic fertility.  What I mean by this it is we cannot just add fuel when the tank is low.  Soil biology is more about allowing it to do what it do.  As I have said many times the goal is a balanced approach.  If we focus on just nitrogen fixation we are not seeing the forest for the trees. If you need any help with this feel free to reach out.

We are now approaching go time with the planters. This is always an exciting and challenging time.  Unfortunately, the rains continue to avoid us.  We need to make sure we are taking advantage of the moisture that we have by proactive management.   As always, if you need anything feel free to reach out.

Hello All,

Another week and yet more interesting weather.  The most interesting was he had 6” of snow with no wind as they were predicting.  As a result most of the wheat had snow laying on top of it when the extreme cold temps came. This was very beneficial.  I have looked at some wheat this weekend and see no ill effects at this point. There was not a lot of moisture in this event but it was still wetter than we had been and more importantly, it covered a fairly large area this time.  Once things do finally dry out things will start getting busy quickly.

I continue to recommend that separating the fertilizer and herbicide is the best agronomic decision. Remember to have this on before joint for the most impact on yield.  This will happen rather quickly once the wheat starts developing.

After looking at several fields yesterday I feel fairly confident that the impact of the recent cold temps was negligible. I am starting to find a few winter annual weeds in some fields this may increase with the surface moisture we have now.

Now I would like to take the time to discuss weed management in this wheat.  Weeds can compete for water, nutrients light and space.  They can decrease yield cause harvest problems as well as combine wear.  This is not an exhaustive list however it does demonstrate the importance on weed control.  When considering weed control in winter wheat this is a process that starts management before and then after seeding.  The goal is to achieve a good stand to help the wheat compete.   Unfortunately for reasons out of our control many of the stands are not as ideal as we would like.  Now we are faced with a potential problem.  When making weed management decisions we will need to know what weeds we are dealing with. There are two main categories winter annuals and spring annuals.  We have some fields now with winter annual broadleaves but, the main concern going forward would be the spring annual broadleaves.  There are some fields with winter annual grasses as well and in many cases we have incorporated Clearfield (imazamox) or Coaxium (quizolafop)wheat to combat some of these.  Once we know the type of weed or species we are concerned with then we need to make a plan.  For example, if our only concern is spring annual (kochia, russian thistle) then we would want to use a product with soil activity. Waiting until the weeds are emerged can be a bit late for many products.  Normally we use a combination of growth regulators and als sulfonylurea herbicides.  The later will give some residual control for approximately 3-4 weeks. One caveat, there is a fairly substantial als resistant so the addition of dicamba can help combat this. The problem with pgr herbicides once the wheat begins jointing we can see some negative yield consequences.  Plant growth regulator herbicides as their name implies, mimic many of the growth hormones in the plants. When a plant starts to growth reproductively the hormones natural hormones in the plant are more active so a negative response to a herbicide from this class would be more significant.  So it is best normally to have fields treated before Feekes 6.  I am not saying we can not use a growth regulator after this  I am just illustrating the concerns of doing so.  I would like to add that we must omit dicamba from any mixes after Feekes 6 with no exception.

As with top dress everything revolves around that critical jointing growth stage. This as you recall is the plant making the transition from vegetative to the reproductive stage.  Please be mindful of the developmental stage of the wheat you are treating before doing so. If you are making an application after joint I would suggest utilizing a bio stimulant in the tank to help the plants be able to detoxify more rapidly.

Glen W. Teels

Agronomist

Pathway Ag