June is here and what a month it has been so far. While we had to endure the coldest and snowiest April on record this spring, the month of May surprised us as being one of the warmest on record for many locations in the Midwest. Then beginning two weeks ago the blast furnace type temperatures crept up from the southwest and reminded us of what summers feel like on the high plains. Being outside in the fields without a cab last week when the thermometers were locked in at the mid-90s made one wish for a nice day in mid-March. Where is the consistency we expected?
Most locations in the Midwest finally got the drier and sunnier weather they were hoping for and the affected farmers finished planting most of their acres. There was movement to earlier hybrids from the very full season varieties that had done so well in recent years. Not many growers like to pay the huge dryer bills that could result if the summer cools down. No one has summarized any movement away from corn in favor of soybeans. Staying with the rotation is typically the best decisions, and in many locations the presence of SCN and resulting lower yields for second year beans generally keeps farmers away from that practice.
In a year when even the climatologist’s weather predictions vary dramatically, we are still left with little clue of what June, July and August will bring. It was interesting to see that the volcano ash plumes in Hawaii have now reached as high as 30,000 feet. This is the level at which they know the ash particles get into the lower atmosphere and can start blocking the sun’s rays, cooling the worldwide temperatures.
Field Observation
The common observation made by most Ag people is that they have never seen the corn crop grow so fast in a short period of time as the plants did this year. Getting 25 + GDUs per day for about two weeks will cause very rapid growth. Will the stalks be as strong this year or might they be weaker? We could see a difference versus normal, and soil test levels for Ca and K could be an influencing factor.
In many fields in central Iowa the plant have reached the late V4 moving into the early V5, which is when rapid growth occurs. This is also when the cautions about using phenoxy are justified. It seems that more corn growers are using Dicamba based products on corn to take care of some of the problem broadleaf weeds. This was reminiscent of the time when farmers would wait until about May 15th before planting beans, so would begin spraying corn before the beans emerged. They knew their drift or inversion problems were minimized if very few beans were emerged in their neighborhood at the time of Dicamba applications.
Rainfall
Early in the season the daily amounts of precipitation used by the plants is very small. As the plants grew from the V6, and later the V8 stage the daily usage will increase, peaking at tasselling time. Stored and immediate moisture typically meets those daily requirements thru April and May. Then as root uptake increases the immediate demand for moisture is typically met by rainfall.
Insect Indicators
The first fireflies are beginning to appear now and their little lights can be seen blinking at dusk. Concurrent with their appearance is our normal CRW egg hatch. This typically takes place when 720 to 730 GDUs have accumulated. So depending on location within the north/south heat unit charts expect the first root feeding to start. This is a labor intensive process that normally involves a spade or sand shovel, buckets and a good higher pressure hydrant. It takes time to wash off the roots to look for feeding damage, and even more time and patience to find the very small larvae. And if you do find them the appropriate question is what could be done to remedy the problem. In the past we have seen the Neem oil based Safe Strike diminish the amount and rate of root feeding. Sometimes the small black headed larvae move off the roots and quit feeding. I am curious and we will be seeing if the Chitosan based products could cause a halt to the feeding.
Another insect that has been seen are the slow flying medium-small flies that move quite slow and don’t move much when you begin swatting them. These are the adults of the seed corn maggots. They often feed on the disked under vegetation of small grains or weeds as the fields were worked. I have seen where they tunneled up the stem of just emerged soybeans causing them to topple over. It takes a keen eye or a good magnifying glass to see the small translucent larvae.
The bean leaf beetle numbers were high in the first planted fields, but now as more fields have emerged those populations have drifted down to where no fields meet the established thresholds. Look for the holes in the leaves and approximate the percent of the tissue lost to feeding.
Herbicide Happenings
Two weeks ago it was tough to find many weed seedlings in the fields. That is no longer the case, as there are high counts of our common weeds in many fields where control was less than expected with about six common broadleaves. There have also been cases where the PPO used last season appears to have carried over. Expect to see stunted, yellowed plants. They typically survive, but grow and develop slower. As to the cause (s) some of the herbicides could have been applied after the July 1st cutoff date or the drier conditions after application slowed down the expected degradation.
Show Me the Money Plot and Field Day
Several of us drove thru and took video of the plot work being done at the Guthrie Center research farm on Saturday. The corn was planted later than in the previous seasons and was now close to the V4 growth stage. It looked very good.
There is an area where a variety of inputs are being applied in tandem or in sequence to see which ones influence the yield or other traits the most. We took a stair-step approach to see if each pair of input products was producing just an additive effect or offered a multiplier effect. For instance, 1 + 1 should equal 2. But if they equal 3 or 5 enough to be significant, then they could offer growers a high ROI.
When we are using several new products the challenge can be identifying the product or series of products that should receive the credit.
We expect to have a plot showing and meeting down at the farm around Aug 20, or before farmers get busy with harvest. Our March 12th meeting in Ames that was attended by 120 note taking growers told us that growers were interested in getting educated and hearing new ideas that seem grounded.
In the meanwhile, we are assembling the BioEmpruv and Argosy that will be applied this week and can be expected to keep the plants alive, healthy and filling until mid to late October. We will also apply the Take- Off signaling compound from the Los Alamos Lab that seems to be working well in all crops. The Calcium silicate product is also in the shed and ready to be applied. If it allows the corn plants to be more stress tolerant and get by with 30% less water while also increasing the RUE (radiation use efficiency), the boosted sugar production should form more bushels. We also have the liquid poly peptides that are giving good results in Brazil. The same goes to the Ensure product, which boosts heat and drought tolerance tremendously. All of these things should help build on a fertility program that is built on soil health and balanced fertility which is accessed thru the use of Verdesian fertilizer stabilizers. This is all good and we are expecting big things. It can still be a case that in the end we will have the answers but might wonder what some of the questions are. But that is how science and producers can make significant advances.
Bob Streit is an independent crop consultant and columnist for Farm News. He can be reached at (515) 709-0143 or www.CentralIowaAg.com.