As we now move into the last week of June and get ready for the important cropping month of July it might be good to look around and make comments on how things have gone so far. So what might different people in different states say? In northern and many parts of north central Iowa farmers are still wishing it would quit raining for a few weeks. In many locations they have had a year’s worth of rain already and their top end yield potential has passed their fields by. Large lakes are numerous enough that our state can likely by pass Minnesota given the fact that we now have closer to 20,000 lakes that are not supposed to be there. This is leading to a multitude of problems that need to be discussed. The top end yields that farmers always strive for have passed them by as the best corn yields typically are not produced when the fields are planted after May 20th while the best bean yields are not mudded in after June 1st.
Things may come out all right on the rolling where water has not accumulated. This is the year when there can be a penalty for farming flat black fields. Having a little to a major amount of roll has its blessings.
Who of us would have guessed a month and a half ago when most of the corn crop was planted weeks late that it would be this far along in development by the end of June. I had to drive thru SE Iowa late last week and saw entire fields tasseled out near in the southern most counties. I can’t remember seeing that ever. The beans are finally growing and giving hope to the men and women who planted them. We just have to hope for favorable weather conditions to help them fill during August and early September.
Field Observations
A week ago after the four to six inch rains fell in parts of northwest, north central, central, and western Iowa leaving large ponds where water sat for days growers were wondering what the long term rules were for the number of days the crops could endure being under water. A lot of articles and my comments were that a big consideration was the temperature of the standing water. Cool water allowed a longer duration for being submerged and warm water shorted that duration. In most cases the temps were very warm the first few days and the shorter predictive times given were accurate. Most of the beans that were under water more than three or four days didn’t make it. The corn seemed to last four to five days before the plants ran out of oxygen.
If the submergence was a one time event it would have been much better, but the same thing happened two or three times within about a week. Thus from the air there would be the 20 or 30 thousand black bare spots that will either grow up to weeds if we do nothing, or the farmers take the risk and absorb the cost of replanting those area hoping for dry weather during the remainder of the season.
Overall the corn crop of two weeks ago was one of the prettiest, most even, and best color we have seen in the last ten years. Then the problems related to too much rain began to appear, eroded fields, lost nitrogen, lack of oxygen to the roots, and so on.
And as a kick to the rear, while farmers and custom applicators in our state have to deal with too much rain and the hassles that come with it, growers in S central Iowa, way northern Missouri, and out in Nebraska have been missing most of the rains and their corn plants have been rolling up severely.
Weed Control
When weed control commercials are made and recommendations are given, the sun shines all the time and the winds don’t blow, so getting the work done within the optimal window is easy. With much of the Midwest getting the work done in that window has been impossible. There are now sprayers parked on the field edges where they had gotten rained out over a week ago and conditions have still not improved enough that they can resume spraying. And have the weeds quit emerging and growing so as to not become a bigger problem to manage? Not by a long shot. So now farmers and crop advisors have to figure out the best way and most affordable way to manage weeds that are much taller and several growth stages beyond what the labels state. A high percentage of the beans have grown to the R1 growth stage where PPOs can do their damage and Rup applications tend to be prohibited. The cutoff dates for the Dicamba applications in states to our north have passed. Pulling the cultivators isn’t an option for most people since the conditions are too wet and there are often too many weeds within the row. This season is a perfect example of why having a great residual program is important to soybean growers.
On the taller weeds when the burner PPO of Flexstar and Cobra or generics have to be applied and you want to reduce the burn I have liked using the Spray Tec products, where the AMS is pulled out the and the oil rates are reduced. But control becomes more difficult if the gallonage is not at 15 gpa and the correct nozzles are not used, as the number of growing points on a 6 or 8” tall waterhemp are much greater in number.
Air Inversions
How many really good articles on air inversions have you read in the past off season? One really good one was written and published by the crop extension staff at the U of MN and SDSU. They included their data and observation made at their weather sites as well as at 31 NDawn sites in MN and DN plus 11 in Missouri. They make observations for air inversions, rating the strength of each inversion as to whether it was one of .1 degree F, .5 degree, >1 degree F, >1.5 or >2 degree temp difference between 1 meter and 3 meters in height above the ground. What they saw was that in every day between May 17th and June 12 they had an inversion. The only difference was how strong they were. They also saw inversions when the winds were gusting to 25 mph. Most inversions broke up within 15 to 30 minutes of. They typically saw the inversions begin to occur four to five hours before sunset.
My thoughts after reading the article is that each of the companies who developed Dicamba soybeans or sold those associated herbicides should have taken such measurements and been asked to provide such information to EPA and state boards before being granted their labels. It they didn’t they should have. And if they did have it but did not provide it, it should be a major point in any negligence lawsuit.
While discussing this point I have to mention that Dicamba drift has occurred in several local fields. In at least one of these plants across the entire field are affected, with very curled leaves and interrupted growing points. In past years the heavily effected fields near Gilmore City grew about 12 inches tall and most of the plants stalled out with very few pods forming. This was very similar to what happened to tame and wild legumes near Orange City last fall, which was followed by major honey bee die-off last winter and late spring. Leaf samples were pulled and turned into a lab with the appropriate LC MSMS for high level detection work. Through this summer we will hear more about this, but the official acreage tally by government agencies will not include these, as most growers learned that fed crop insurance will not pay for low yields if Dicamba drift and not weather or a natural event is the cause. It’s a situation where honest people will not get rewarded.
Bob Streit is an independent crop consultant and columnist for Farm News. He can be reached at (515) 709-0143 or www.CentralIowaAg.com.