Corn Borers, Spider Mites, Thrips, and Leaf Hoppers

by | Jul 8, 2021 | Crop Watch

Another page on the calendar gets turned over and we enter the month of July. It is typically the month with the hottest temperatures and less rain received than the crops use, so the plants are relying on deep profile moisture to form the pollen, extend the silk and get the pollination sequence over with. In a normal year we begin the season with eight to nine inches of moisture stored in the top sixty inches of soil plus deeper in the profile that the plants can extract if they need to, there is no serious compaction, and the hybrids have the penetrating ability to reach deeper than five feet.

As to which events have occurred in the state in support of Agriculture there have been two. The first relates to one that was way past due. For the past two or three decades, and especially since JBS moved into the U.S. the majority of profit in the beef raising business has gone to groups of monopolistic packer owners. When any business gets down to three or five big boys, the actual producer who put their hearts, souls, money and time into buying the feeders and doing the best job possible growing them, and the cow/calf boys deserve the bulk of the margins. The organizers of the Cattlemen Heritage deserve a lot of credit for their plans to build a beef plant just east of Omaha. Now it sounds like a similar effort has been organized to construct a slaughter plant for pork producers near Sioux Falls, SD that would service the many producers in the four-state area. The FB spokesmen reported this week there is still grant money available to build smaller scale butcher shops in smaller towns which have been overwhelmed by demand and 12 – 15 month waits to get their animals in for processing. It is another case where actual producers join together to develop the solution they needed.

Politics wise it is good to see the state’s businesses open up and July 4th festivities go on as normal. I especially enjoyed watching Ohio Congressman and ex NCAA wrestling champ, Jim Jordan, tear into Fauci and his minions after he dug up their email chain where they organized their year-long and worldwide disinformation plan on the development of the pandemic and coverup of their involvement along with their Chinese counterparts. Look it up.

Dry Weather Problems Most farmers can recite the exact years when they farmed and had to endure long droughts that tested their mettle and destroyed their plans to harvest bountiful crops. Long ago there were the dirty 30 and the early 50s. I remember 1964, 1977, 1987-89, 2011-12 and finally 2017 in the four-state area. We can likely add 2020-2021 to the list but one can only do so after the dry weather has come to the end.

At this point much of the state and neighboring regions have gone since April 1 st without any rain over one inch and accumulation totals of less than two inches. Every front coming from the westerly directions seem to change course or dry up as the storm clouds encounter the super dry air over Iowa and fall apart. People who are concerning are asking how much longer can our major crops survive, and ones hates to take any educated guess. Currently much of IA, both Dakotas, Wisconsin, Montana, sections of Mn and the dryland parts of NE need rain shortly to save the corn crop. Last week I was in central and Northwest Iowa and saw fields where the corn leaves were rolled up by 9 AM. At a designated point each hour over 86 adds to the total and after 150 total stress days the final yields will be reduced by double digits.

This past week one can identify fields that are particularly at risk, such as second year corn, fields with shallow and deep compaction zones, spots with lower organic matter, insect or planter problems which compromised root system intactness, varieties possessing shallower root architecture, areas with reduced soil biology content. I have been in corn the last week that was as tall as ten feet as well as quite a few fields that are not much more than fence post high and beginning to show the tassel leaf at a plant height that will be much shorter than normal. Without measurable rain in the next ten days the plants in the fields taking on the gray color could be relegated to yields well below trendline yields.

Fields where the operators have been trying use cover crops in past years to build soil organic matter are tolerating the drought much better. A good tool to use is a laser heat gun that allows a person to measure leaf temps. A plant with enough moisture to cool the leaf will show a temp reading lower than air temperature.

Soil Health Academy

Mitchell Hora of Washington County held his soil health field day in Washington, IA in early June. He drew a very large crowd and the ages of the attendees ranged from in their mid-60s to early 20s. They now categorize their efforts as regenerative Agriculture as sustainable really does not spell out any particular program or improvement as their members stated goal. Rick Haney attended and told that his goal was basically follow what nature had done in forming the rich topsoil where tall grass prairies had produced lush grass for grazing animals to eat for thousands of years. Rick goal is to try to convince growers that planting into a living cover crop should be possible based on their latitude and length of growing season.

Following that meeting was a Soil Health Academy conference where about thirty farmers and consultants from across the U.S. gathered to hear from guys like Gabe Brown who grew his cash flow tremendously on his N Dakota ranch while he increased his organic matter to the point they produced well in spite of four years of scant rainfall. His region is now in their sixth year of drought and he has sixty- year-old trees dying from lack of water.

One officer of the group is an Indiana grower who thru the planting of wheat every third season and planting a rye cover crop, had increased his organic matter from 1% to over 8% with no livestock in his operation. That permitted his crops to tolerate longer dry periods, which are common in July and August in most Midwest states. I hope to have a few more phone calls with him to find out his details, as many operators would like to hear their lessons and secrets

Remember that there were plans to build two new soybean crush plants to handle the expected six million acres of soybeans to be planted in his state in 2021. The same degree of dryness is affecting major parts of SD, Mn, Wis, Mt and Mi.

Lance Gunderson is the fellow who ran and explained the Haney test results to people that utilized his work with Ray Ward’s lab in Kearney, NE. He has a PhD in his background plus actually farming, so he understands and can explain what Haney test results are telling growers who have sent in their samples. One thing he has been doing is when growers are growing cover crops, especially legume mixes, he will analyze samples of the above ground growth for N and other mineral content, add in the Haney result, and prescribe a N program of hos much additional N would be needed for the following crop of corn. He told of one NE grower who terminated an alfalfa crop. After Lance did the testing he prescribed only 30 lbs. of N to produce the goal of 230 Bu/A of corn. The guy was flabbergasted, but by trusting Lance’s recommendations he actually produced 235 BuA in the field, saving a bundle on nitrogen.

Tissue Testing Results

Tissue testing is the only way to determine how effectively each applied minerals is actually getting into your plants. By being alerted to any deficiencies early, enough minerals can be applied in corrective fashion. At this date high clearance sprayers or airplanes are needed to make applications to corn. This season I am seeing moderate to extreme shortages of Moly, Boron, Mn, K and Zn in many fields. Until you gather enough experience it is best to verify suspicions by have the lab analysis done.

The common question then it which types of fertilizers can successfully move into the plants and into the cells to correct diagnosed deficiencies under dry conditions. From visiting with several experienced mineral people, I am learning that Midwest growers and retailers have not been steered to the most effective products. We will post information from two or three companies on our site that are introducing so called amino acid or phosphite chelated fertilizers that can produce nice responses with minimum amount of product. One observation is that if the soils are extremely dry there is not enough water to carry minerals into the plant, Direct leaf application can still do so. A discussion on this topic may involve chemical terminology such as molarity, valency and Avagadros constant.

Corn Borers, Spider Mites, Thrips, and Leaf Hoppers, Not as Catchy as Lions and Tigers and Bears 

These are the legged critters that can be found chewing on your corn plants and possibly bean plants now or soon. This was to be year #4 of the 5-year ECB population. The first brood has just shown up in extreme NW Iowa. If you are growing conventional hybrids be aware of these and do your scouting. Know what each look like, what their feeding looks like, cost of control and treatment thresholds. Spider mites can be found in small colonies on the underside of corn leaves close to the ground. They multiply faster in high temps and not destroyed by a fungus when conditions are dry. Thrips and leaf hoppers are present on soybean leaves, typically not a problem in a normal year. This year is not normal though.

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