About Your Fields March 19, 2018
In this Issue:
1. Your House is Now Complete, It is Time to Feed the Occupants. Boron & Zinc.
2. News That Caught My Eye
Your House is Now Complete, It is Time to Feed the Occupants
Your house is now built and it is protecting and nurturing it's occupants (the grain), it is now time to look at how we are feeding them. This week we will start looking at some different Micronutrients and how they work in the plants. This week we will talk about Zinc and Boron, why they are necessary and how they interact with other nutrients.
The first nutrient that I will discuss is Boron (B). This winter I have attended several meetings and this nutrient seems to be receiving more attention now than it has in the past. Boron is a key element in both a plants early growth and reproductive development. Boron will help a plant move sugars and carbohydrates throughout the plant from the leaves all the way down to the roots. It is essential in helping a plant regulate water levels by helping to open or close stomata in the leaves, which regulates what is allowed to enter or leave the plant. It accomplishes this by pushing potassium (K) into the guard cells of stomata to close them, and pulling potassium out to open. It is because of this that you need to ensure there is adequate supply of potassium available when thinking about adding additional boron. It is also involved in nitrogen metabolism and protein formation. Boron also plays a key role in cell division to help build a bigger plant. Because of this if boron is deficient in corn you could see shortened internodes. If it is severely deficient the whorl of the leaf might not come out. During pollination corn plants deficient in Boron could have blank stalks or ears that are “Banana “ shaped with part of the ear blank. Since it is a micronutrient, very little is needed for the crop. Soil sampling can give you an idea of where you are at but tissue testing is the most acurate way of determining levels. You do not have to have a high level of boron to be sufficient, a plant tissue test of .5 ppm to 2.0 ppm is adequate in corn. In soybeans deficient plants will see shortened internodes just like corn, but the stems will be thicker similar to what is shown from growth regulator damage. You could also see crinkled up leaves or “cupped” leaves as you would with growth regulator damage. The way to tell the difference between boron deficiency and growth regulator damage is that with boron deficiency the leaves will cup downward and herbicide damage usually cups them upward. If a soybean plant is deficient in boron during reproduction it will possibly have trouble flowering. As in corn, the best way to detect a deficiency is by taking a tissue test. If the test shows up low the best way to apply boron would be using a foliar treatment.
10% liquid boron applied at 1 qt/ac is the most common form of boronin ag. It can be applied in starter or foliarly applied. We at Akron are still looking for the best deal for our customers, but a liquid boron is going to run less than $14/gal. While we have promoted CoRoN in the past as a nitrogen source, it also contains boron.
Our next key nutrient to discuss is Zinc (Zn). Zinc is usually one of the key nutrients that is deficient in tissue tests at the highest frequency. I have seen results from a large volume of tests conducted in both Iowa and Illinois that showed over 70% of the samples came back deficient. Zinc is a key nutrient in corn production both early and late. In the early stage of corn production zinc is a key component to help determine how many rows a corn ear will have. It is because of this that we recommend that you apply zinc in furrow as a part of a good starter fertilizer program. If you look at Mulder’s Globe you will see that Zinc has a direct relationship with Phosphorus. Zinc uptake is increased when the mycorihizae, a fungus in the roots is present in a high level. High levels of phosphorus reduces the number of mycorihizae present in the soil. If you have P tests, an additional application of zinc might be necessary. A pH below 5.0 and above 7.0 will also reduce the availability of zinc in the soil. A corn plant that is deficient in zinc will usually be stunted in it's growth. The leaves of the plant could show some bands of pale yellow to white running longitudnal on both sides of the midrib with a severe deficiency causing some leaf necrosis. The best way to see if your plant is deficient is to take tissue samples. Since the symptoms during reproduction will show up in the middle of the plant first, take the two leaves above and below the ear for your sample. If you have a cool and wet soil early, zinc uptake will be hampered and you will need to send in the whole plant. Zinc deficiency will not show up uniformly across a field, so you will need to look around to see if it is present. Lately I have heard several people talk about split applying your zinc, putting some in furrow at planting time and some later at sidedress time. One way to apply zinc at sidedress would be to use it with a Y Drop application. This would allow you to put the zinc closer to the plant's roots and utilize it more efficiently. In soybeans, zinc is rarely deficient, most soils are able to supply the amount needed for soybean production.
If you want to use zinc in your operation, we recommend Trafix Zinc as a economical and good Zinc source. It sells for 11.70/gal with a 1 qt/ac use rate.
If you have any questions about boron or zinc please give one of the Agronomists here at Akron a call and we would be willing to discuss how we can help your situation. Next week as we continue our nutrient discussion the focus will be on Sulphur and Manganese.
News That Caught My Eye
For the past several weeks and for the next few weeks ahead I have been talking about ways to help you grow more corn and soybeans. In the next few weeks many of you will start taking the next steps in getting your ground ready for this year's crop. As I was looking through several different websites I came across an article in Sucessful Farming in which Purdue University Extension Agronomist Bob Nielsen talks about your corn stand. Now the ironic thing about this article is that it is really a recipe for how not to get your field ready. In it he tells you to make sure you have saturated soils. Wait till the last minute to kill off any winter annuals that might be growing. Make sure you plant you seed when the soil temperature is expected to be at 50 degrees or less for the next three weeks after planting. Along with other "helpful" hints in how to get a bad corn stand. Now we all know what we shouldn't do in order to get your best corn stand starting out. I feel that the real take away from this article is that you only have one chance to do it right. I know the temptation will be out there to go and start preparing the ground just like your neighbor is doing, but make sure that the conditions are right so you can get an optimal stand right from the start. If you would like to read the article on what not to do click on this Dr. Bob Nielsen Corn Stand Recipe.