By Ryan McAllister, CCA, Team Sales Agronomist, Beck’s Hybrids
In this agronomic update I want to take some time to discuss the two most common questions I am receiving from growers as of late. Those questions are…
1. Why are areas in my wheat field turning white?
2. Why is my corn leaning over? It looks like chemical injury.
First, there are several reasons why your wheat may be appearing to reach maturity early.
1. Nitrogen deficiency: with the abundant rainfall we received this spring, our wheat plants are running out of nitrogen. When a grass crop runs out of N it begins the process of cannibalization. It will cannibalize itself to make grain. Therefore, we are seeing wheat fields that are prematurely dying due to this nitrogen cannibalization.
2. Low areas or drowned out spots are dying sooner due to anaerobic conditions from waterlogged soils earlier in the season. These same areas also run out of nitrogen sooner as well.
3. If you notice your wheat turning on the hills first, not where it is the wettest or low lying areas of the field, I have seen what appears to be “Take-All Root Rot” in eastern Indiana and Ohio wheat fields creeping in. This soil borne disease causes premature death of the plant.
4. You may notice white heads but not necessarily plants. Head scab is once again prevalent this year. This is caused by the fusarium fungus being present and a rain event during flowering. Even those fields sprayed with an appropriate fungicide for scab control are still having scab incidence. Remember, those fungicides do not provide 100% control. Also, scab control products must have been applied during flowering. If that small window was missed by even one day or two, I have seen head scab as high as 50% in those fields.
The take home message for wheat is that if premature death and resulting cannibalization of the plant occurs prior to the grain being past dough stage, lower test weights can occur and should be expected. If this happens after dough, there should be little effect. The heads I have looked at that have scab already have shrunken grain that will not fill out. Most of those heads should be blown out the back of the combine to help quality, improving test weight of the crop, and marketability of the grain.
I have also received many phone calls lately as to why corn looks like it has chemical injury. Many growers state that they have not applied 2,4-D or dicamba products, but their corn looks like they did. There are a few reasons as to this phenomenon.
1. If it appears that your corn is leaning over and it starts at the soil surface, sometimes even beginning to pull the first set of nodal roots out of the ground, check your planting depth. Many times, this is due to shallow planting from a quarter to three quarter inch deep, or even up to an inch deep. Check the distance between the seed and the soil surface. You can still find your seed attached to the mesocotyl if you dig gently.
2. If it appears that your corn is leaning over and the bend starts a few inches off of the ground, this is usually not a result of shallow planting depth. Sometimes when corn experiences average to below average growing conditions and then a very abrupt change to 90+ degrees, moisture/excellent growing conditions, it begins growing so fast that it “flops.” This can cause some challenges when it comes to sidedressing.
The take home message for corn is that if you are experiencing these symptoms due to shallow planting, then that is potentially more detrimental. You need a rain to help those nodal roots get established and pull that plant back erect. Sometimes when it does this, it may goose neck a bit. Don’t assume that it is rootworm if you see this.
If you are experiencing these symptoms due to fast growth and the bend is above the soil surface, that corn will grow out of it and no negative effect on yield should be expected.