About Your Fields August 6, 2018
In this Issue:
1. How is the Heat Affecting my Crops?
2. Field View- Insect and Weed Watch
3. What's Next?
How is the Heat Affecting My Crop?
As we close out July and enter the month of August we are entering a vital stage in your crops final maturation. What happens the next 30 days will determine how much yield we can expect when harvest starts in September. Last week we talked about how the lack of rainfall could affect things like kernel depth and pod fill. I looked up the drought monitor for the state of Illinois and it shows that are area is within the normal range.
I also saw on tv last week a report from one of the local weathermen that the Peoria area saw nearly normal temperatures and a little over a half of an inch above normal rainfall. Most of the surplus came in a late rain event on the last day of the month where the Peoria area saw slightly over an inch. For most of you these rains have been spotty at best. For example a mile and a half west of the Edelstein elevator had 1.2 inches last Thursday and the elevator only had .2 inches. Another example is the area over by the Caterpillar Tech Center in Mossville I was wanting to spray 2 foliar soybean plots. A quarter mile north there was rain, same to the south and east, but not where I needed to spray thankfully.
So what is doing to the crops? The most important thing that the heat is causing is stress. This is the one thing that we try to avoid as much as possible in a plant, whether it is soybeans or corn. In my opinion soybeans can probably handle stress better than corn, but it is still something to be avoided if possible. Soil type can play a large part in how much stress the plant experiences. Look at the two pictures below, they are both located within a half of a mile of each other. The one on the left is showing a significantly higher level of stress than the one on the right.
The picture on the right is one of our plots that we sprayed with different biological products, if we see any changes we will post new pictures in the coming weeks. Also look for the yield results that we will post this fall once harvest is completed to see how they yielded. The picture on the right has more clay and sand than the other field pictured. Both are showing some amounts of stress as they have flipped their top leaves over to protect from evaporation. While pods are not being aborted yet, if rain doesn't come soon that is what could happen.
In corn the lack of rain and higher stress levels are starting to show up a little more prevalently. Last week we talked about how we could experience shallower kernel depth due to lack of water. As I walked fields this past week I started to see other signs that we need to keep track of as the season progresses to harvest. One thing that we are starting to see is some possible stalk rots, notice the spots on the stalks in the picture below. As you can see we have some firing taking place here in the lower canopy, but some hybrids are showing these dark spots on the lower stalk. These spots could be the first sign of some Anthracnose starting to set in on these plants. When I walked and evaluated the different hybrids in our plot I found that these dark spots were more prevalent in the later season hybrids that had a little more top end potential. If this disease progresses we will have to keep track and make sure and harvest those racehorse hybrids before they go down.
The other issue that we have observed is tip back on the ear. Now I hope to see a little bit of tip back on the ears no matter the hybrid. If you don't see a little tip back you did not plant that particular hybrid in a thick enough population. If you look at the pictures below you will see that there is the ear on the left that shows what I would call a normal amount of tip back. The ear in the center starts to show a little bit of kernel abortion brought on by stress. And the far right picture shows a good couple of inches of kernel abortion. I can tell you that these all came from the same field, planted the same day with the same population. Maturity did not affect what we see because the far left hybrid is a 112 day maturity, the middle is a 108 day hybrid, and the far right is a 114 day hybrid. I feel the major difference is that the 114 day hybrid needs more management, than the 112 day hybrid. This is why it is important to plant a good mix of racehorse and defensive hybrids, to spread your risk.
The take home message I would like you to get from this article is that, the next 30 days will shape what the final outcome will be with this year's harvest. We need to monitor for any potential problems especially in the corn crop. There is not much we can do, but it is time to evaluate for next year.
Field View Insect and Weed Watch
Last week we talked about soybean aphids and what their potential could be this year. Going into the weekend we had conditions that were pretty much optimal for their reproduction. The fields that Neil and I walked this past week did not show any signs that the populations were going to increase any time soon. The heat that we had this weekend was enough to slow them down as they do not reproduce very well once you get close to 90 degrees, but don't stop looking for them. Most of the soybean crop is in the late R3 to early R5 stage, depending on planting date. You are not really out of the woods until we hit R6 when it comes to potential yield robbing damage from this insect. If they are going to be a problem this year it will happen in the next two weeks, because that is the historical time that they show up. If you think you have a problem give myself of Neil a call and we can come out and give you an assessment of what their potential for damage could be.
One thing I am interested in looking at this year is whether or not we will see waterhemp start to show it's ugly head above the top of the soybeans. Rain in late July and early August usually see a late flush of this particular weed. Scout your fields and see if it happens this year. If your fields stay clean then you made a good decision about your herbicide program. If they start to get dirty in a few weeks visit with us and talk about your options. As I drive around I see many fields with volunteer corn sticking up a little bit. One thing to remember is that if you sprayed dicamba with your post grass herbicide, you needed to use a higher rate to get an effective kill of volunteer corn. If you sprayed Liberty on your soybeans post with nothing added because you sprayed Roundup on the corn last year, most of the corn is tolerant of Liberty herbicide. This is the time to evaluate and make notes to help us serve you better next year.
What's Next?
As the calendar flips to August, and the kids go back to school, it's time to start thinking about fall and what you are going to need fertility wise. Many of you had ground soil tested in the last year and you will be needing lime spread. Once again lime will be in tight supply, so you need to talk with Sam about getting it hauled and stockpiled this summer so it is ready to go when the crop is out. Some of you need to get your ground tested, if that is you, contact Neil to get on his list for sampling this fall. One other thing to think about is that with potentially lower commodity prices VRT spreading might be a more efficient and cost effective way of spending you fertilizer dollar this year. Talk with any one of the agronomists at Akron about our variable rate fertilizer program.