Goss’s Wilt and other challenges

by | Jul 9, 2017 | Crop Watch

It is tough to believe but since we have passed the 4th of July holiday the first half of the summer has been completed. Last year quite a few corn fields were approaching the tasselling phase and were past head high. This year the rainfall interrupted planting season and lack of heat units has created scenery across Iowa where the height and development stage of fields varies dramatically in each country and by each region within the Midwest.

Rainfall or lack thereof is what is in most farmers’ minds. After such a wet start it is strange, but not unexpected, that the storms have been shut off for much of the state. The storms are continuing to move thru Southern Minnesota and bouncing into extreme northern Iowa, but much of the rest of the state have been dry now for several weeks. We have all heard the reports out in the Dakotas where much of the winter and spring wheat had been baled up for feed several weeks ago. In those two states the remarkable change in their cropping is that corn and soybeans are now two major crops they now plant and have to manage. Production in their states is not on the scale of the five major corn rowing states, but does contribute greatly to the overall grain supply. The big rain front coming thru overnight on Sunday/Monday slipped by and dropped significant amounts of rain on the northeastern 40% of the state.

One event that happened for me this past Saturday was to attend the funeral for a farmer friend in Cherokee, Iowa. He attended ISU to prepare for being a Voc Ag teacher and he did that for several years. From there he moved on to Felco and Land O’ Lakes as a salesman before setting in as a farm manager for the Iowa State Farm Manager Association and finally as a full time farmer and pork producer. He was a great proponent of each farmer having written goals and to figure out what three things they did best. To do that, he favored studying the farmers operation and trying to spot each of their strengths and weaknesses. As a questioner he was like an old experienced baseball pitcher who might throw fastballs, four seamers, curve balls, back door curves, sliders, screw balls, knuckle balls and change ups from the straight overhand position, then the ¾ position, sidearm and then submarine. Of course this old pitcher was ambidextrous. Outguessing him and knowing what he was going to ask was a challenge, but it always made his farm management clients think and prepare better than they would have done otherwise. We said farewell to him as his body gave out recently and he moved into hospice. Lots of people attended the wake including a number of DVMs from ISU as Jerry was a huge booster of the Cherokee Co Pork Producers as well as recruiting nationally known swine vets to move to ISU. Best of luck in this new part of your journey and best wishes to his family members.

The Big News

In agriculture the big topic of discussion during the summer is always the weather, and what the moisture status is for different parts of the state and Midwest. With the last few weeks being dry and the corn approaching the tasselling and pollination phase, much of the state and entire region’s growers recognize that getting a measureable rains in the next week or two will be important to final yields. The daily ET or expected daily usage of a 5 or 6 ft tall V12 corn plant will be around .20 to .22” per day. This will accelerate to about .25 to .27 inches at the tasselling phase and thru to the late blister stage.

In 2016 the corn crop appeared to be lost until an unexpected flow of moisture snuck through the standing high pressure ridges and dropped a good rain across much of the state opening the floodgates. In driving to and from Cherokee we were looking at the crop development in each county. It was apparent that corn west of Ft Dodge had been planted later and not much of it was taller than a fencepost. This heat and lack of moisture seemed to be slowing the plants down. Will they grow much taller or not? Can the tassels extend fully? Already some silks are appearing before the tassels have extended. That should be an advantage this year.

Soybeans in Iowa and other surrounding states seem to be developing at a slower pace than expected and growers are wondering why. Is it lack of heat units, cooler soils, cooler nights, poor root expansion, poor early drainage, etc…? It is likely a combination of those factors. Will the rows on 30” rows ever close and will they form enough branches to accumulate enough podded nodes to yield well. If we receive sufficient rain it would be the time to make foliar applications increase the efficiency and rate of nutrient uptake to first force more branching and flowers, then later to supply the P and S that are most needed during pod fill.

From a moisture usage standpoint having three weeks of relatively cool conditions helped reduce water uptake. Once the rows close moisture uptake (ET) by the plants approaches the usage by corn plants. The plants can actually shrink of flip their leaves during periods of stress. On our trip home from Cherokee on Saturday the corn plants were showing rolled leaves giving the pineapple appearance.

Dicamba News

The news about Dicamba soybeans and drift complaints from the application of the herbicide keep coming out of MO, ARK and now TN. Aaron Hager with the Univ. of Illinois is reporting their first complaints. This is before the major lawsuits over 2016 drift have been heard in court. If you noticed the lack of boxes of Missouri peaches in Iowa grocery stores last summer it is because they had a major Dicamba drift even near their groves last year, as did Stark Bros. This has lead to class action suits in Missouri that keeps adding plaintiffs to the suit. You can refer to Bader Farms and look up the details.

One side claims they were not liable because it was not their product drifting. The second side lays an analogy related to being responsible for an attractive nuisance, as in leaving a ladder up against a barn that some kids climb before falling off. Taming a product with a high vapor pressure may not be possible. If the German chemists have difficulty doing so, can anyone?

Reading the facts about air inversions in the Minnesota IPM Newsletter one had to conclude that there is an inversion nearly every day if it cools off as the sun goes down. Duuhh….  I know there are trials being conducted to see if polymers could be used for that purpose. But if you are the third party you don’t relish the thought of getting involved in such litigious events.  The entire event illustrates what happens when, for twenty years, most of the dollars that were spent by growers went down one rabbit hole rather than being spread among ten or twelve different companies that had basic research programs. Innovation was stifled and new products have been a rarity. Now when farmers really need help with tougher weeds there are few alternatives. The bigger companies still involved are huge and also have pharmaceutical divisions that offer higher ROIs and Ag is the poor stepchild for research money.

Goss’s Wilt and other Challenges

Other states are also announcing the finding of the systemic Clavibacter caused disease in their commercial fields. Add South Dakota to the list. With their drought conditions plugging of the vascular tissue could be more serious than where moisture levels are closer to normal. Here it can be seen in most fields as the small brownish slimy lesions down near ground level. Farmers can still take action but now application must be made via high clearance sprayers or aerially.

Soybean aphids are also being found in high numbers in S Dakota fields. Levels have been above treatment thresholds for several weeks and have not disappeared. These have to be monitored and typically move with the wind as the winged adults form. Will that be into Iowa or Minnesota or further north? Time will tell. Remember that our worst infestation was back in a droughty 2003.

Another winged friend, the Japanese beetles, are also showing up after disappearing for a few years. They have been feeding on plants they find tasty the past two weeks. Corn silks could fit that category as can soybean leaves. Keep an eye out for heavy feeding in fields near trees and towns.

Bob Streit is an independent crop consultant and columnist for Farm News. He can be reached at (515) 709-0143 or www.CentralIowaAg.com.