Renewable Farming

Streit: Nutrition points to check if your yields come in a little short of expectations

Oct 18, 2016 — By Bob Streit, crop consultant —   The month is over half complete and harvest progress is moving along erratically. In spite of often rosy weather predictions, many of the days end up cloudy and overcast with accompanying drizzle, instead of being warm and sunny. It is tough to combine beans on that sort of schedule. Most operators hate to switch to soybeans for a few hours of combining when there are lots of corn acres yet to get done. Across our small state of Iowa there are operators who have fields dry enough to not worry about mud and have gotten done already. On the opposite end are larger farmers working on fields where there is still water sitting, and grain of questionable quality still on the stalks or in the pods. And everyone knows that winter is a week closer than it was a week ago.

A short story I will tell now — you may or may not enjoy.

Two farmer friends were wandering around the State Fair this summer and stopped at a place called the Crystal Studio. The sponsors had placed glass jars on the counter that were labeled for the two presidential candidates in which voters were able to drop kernels of corn into. The difference in the depth of kernels was dramatic and counter to what they thought it should be. So being persistent types, as all crop and livestock farmers have to be, they followed the attendant behind the Wizard of Oz type curtain, where they were keeping the official candidate tally on a blackboard. That tally varied widely and opposite of what the jars indicated. When they pressured this person for the straight scoop, he/she volunteered sheepishly that the bigwigs told them to make the one candidate look good. And that is why none of the Wiki-Leak emails about Yoga and someone’s wedding (Ha ha) surprise us in this campaign year. If it happened in DM it can go on all over the country.



There is a big disparity in harvest progress between east and west of the Mississippi River. That may be good, in that an early maturing crop can either indicate an excess of heat units, very early planting, or early or premature plant senescence. The eastern states are farther ahead of the western states with Illinois likely setting the pace. Many of their corn growers with their larger planters and early dry conditions finished planting before we did. Our weather forecast of cold and wet conditions moving in caused farmers to delay their corn planting into the second period which was about May 10 to 15th.

Corn yields are varying with the better yields showing up where extra nutrition and attention to plant health paid dividends. There were cases where everything was done right and yields were still below expectations. What may have led to such shortfalls may have been the excessive heat of June and July where many nights stayed above 70 F. and were coupled with severe drought and the leaves were rolled tight by 7AM.

Even the ISU extension agronomists wrote about how their models were predicting an 11+ % decrease in yield. Another factor to investigate in future years will be to see if shortages of Zn, Mg and Cu or of Moly did not allow the plant to convert applied N to harvestable yield. When a number of agronomists looked at tissue test results from the last few years, those elements were often quite low.

Dr Sasseville, one of the authors of the recent textbook on tissue testing, notes that a shortage of Moly can create an appearance similar to N shortage with yellowing leaves. It is essential for N fixation in plants as well as reduction from nitrate N to NH4. The greatest chance of deficiencies will be on well drained calcareous soils. In the tissue testing I did this summer, the results showed Moly deficiencies in both corn and soybean plants. It sure appears that using it should be investigated by more agronomists and growers. Greater N efficiency could reduce the amounts applied and better conversion into bushels harvested.

Soybean yields have ranged from very good to fantastic. Most bean plants got overly tall. So much that the plants in many fields crouched down and it was impossible to walk through them. We were lucky that the soil temps were warm enough at flowering that while mold did not become a problem, it could have easily been a real issue. The taller plants led to more podded nodes. Adequate fertility levels and little stress thru August led to greater pod retention and higher filled pod counts.

Admonition for 2017

One alert University crop advisor has already recognized that mudding thru corn fields to get them harvested has sometimes left deep ruts. This compaction, if not relieved, could create the conditions for an SDS problems in next year’s beans.

That would make it the third year in a row with mid-major problems. One product that growers may want to get educated about is a product called Full Tech Cube, which is a Brazilian mineral based compound that was tested in different fields and plots and looked very good against most fungal diseases including Fusarium vulgiforma. It was also compared with foliar applied fungicides in plots and in fields and it performed very well. In Argentine work, such products were combined with biologicals to provide long term control of fungal and bacterial diseases.

One of my customers had to rely on either a copper, a copper phosphite, or a zinc manganese phosphite to control severe bacterial pustule problems that caused leaves on the lower 12 to 15” of the plants to fall off weeks early. The Brazilian company may be holding a meeting in DM November 18 to discuss mineral nutrition and plant health.    

After visiting with Dr Tamra Jackson of the UNL last week about Bacterial Leaf Stripe or Streak, the newer, possibly serious corn disease last week and learning that very little was known about the pathogen and treating it, it was easy to accept the fact that we need all possible solutions tested in the field next year. Having new bacterial diseases is what was predicted by insightful scientists about the future.

One other product we have been investigating is called ‘Take Off’ from Verdesian Plant Sciences. It was discovered by scientist at the Las Alamos National Energy Lab. Apparently they found that it set off an enzyme reaction that instructs the corn plant to scavenge for as much N as it can, and they used it very efficiently. It looked very good in their research plots. One of them was at Guthrie Center where we also combined it with the BioEmpruv. Those plants were still green and filling into the end of the first week in Oct. Reports as of early Tuesday morning were that yields from the corn or corn wet soil sections were in the high 200s. It will be fun to see the final yields next week. There were a number of fine tuning and low expense items that really seemed to fit into a nice system that worked.

Palmer Pigweed

Our youngest daughter’s wedding was held a week ago down in St.Louis. In attendance was the endowed chemist from Washington University, also known as the Harvard of the Midwest. His group is very interested in biofuel and feedstock production. We struck up a conversation and I told him that he would have statues built in his honor if he could find a valuable product that could be produced from Pigweed plants. So I am sending him pictures of the new Palmer amaranth plants that have been found lately in many spots in Iowa and now Minnesota. So now instead of Minnesota farmers talking about how good the Vikings have been this fall they can now add in some wisdom about Palmer pigweed. In their case the infected seed came in with pollinator set-a-side seed as did most of ours. In an excellent U of MN extension bulletin the authors provided info on plant ID and management. You can see this at

SCN Sampling

With an increase in SDS problems and the discovery in recent seasons that the nematodes are surviving and reproducing on plants with the PI88788 Fayette gene it may be time to be pulling soil samples from fields to see what your ‘tode’ populations are. Once you get the results back you may then have to decide what your action plan must be. Selecting a high yielding, yet defensive Peking variety and/or using Evicat, ILeVO or a Dactylaria fungal product may required.

 Environmental Health Symposium

The first Environmental Health Symposium organized to educate and familiarize MDs who wish to sleuth and document the root causes of some of the current medical problems was held last March in San Diego. The second one is being planned now. We need to set a goal of getting 100 physicians from the state to attend. Check the 2016 web site and talk to your clinic’s staff or MD about attending.       Here’s the link.


Bob Streit      Boone, Iowa 50036 (515) 432-0907