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Crop watch

By Staff | Jul 1, 2020

The longest daylight hour day of the year is here and with it come a few benchmarks. The sun is supposed to rise at 5:45 a.m. and set at 8:49 p.m. At 42 degrees latitude that gives us 15 hours and 4 minutes of sun up conditions. The longer days will trigger soybean plants to flower if they have reached the V5 growth stage. Those growers who planted their beans earlier than normal are hoping to start forming nodes earlier, thus get more of them before fall senescence occurs.

The markets continue to inch upwards but not as much as we would like. The Chinese grain purchases have continued as they seem to think that crop yields in different exporting countries this fall may be lower than projected. Any sale is a good sale though so we have to hope they continue and in larger quantities. As more states reopen their economies the market demand for raw commodities continue to work upwards slowly and getting closer to the pre-virus levels.

So far the moisture situation in the Midwest states seem to be one of two extremes. Most sites are either low in topsoil moisture or receiving too much rain and have problems with ponding, erosion and nitrogen losses. Here in central Iowa as of 9 p.m. Sunday the weekend total was around .2 to .4 while just east of I-35 have received triple what they needed. With much corn at or close to V8 daily ET is getting close to .15 to .18 per day. It is good to not accumulate more than a 2-inch deficit.

And before getting into the meat part of the column I hope every father got remembered by their wives, kids or significant others. Fathers everywhere, and in all countries, generally have one goal, support their family and try to make their kid’s lives better.

A new book

John Kempf, the younger Amish agriculturist from Ohio who we hosted a meeting with a few years ago, wanted to know if we would spread the word that he has compiled a book about regenerative ag. He does a regular podcast where he interviews notable farmers, consultants and scientists on that topic in his long term quest to get more changes implemented over the next two decades. He has a great ability to hold thoughts and ideas, then interpolate them with previously gained information. This book entitled ‘Quality Agriculture’ should be available through Acres USA Publishing in mid-July. He believes that only going so far as ‘sustainable’ agriculture does not correct previous wrongs and does not fix things. He has gained access to many very good people that I had gotten to know in his popular podcasts.

Crop growth

Corn: The past two weeks we have seen the corn plants advance from short and yellow, often in the V3 to V4 growth stage, to finally getting the heat and sunshine they needed. Many fields hold plants that are now in the V7 to V8 growth stage and often a bit more advanced. If temperatures continue to reach the mid to high 80s most days we will soon be able to calculate projected tasseling dates. Thus corn at the V8 growth stage may form from 2 to 2.5 leaves per week. If the average corn plant forms a total of 18 leaves, it needs to add ten more leaves. That means we can expect tassels to be showing in 4 to 5 weeks.

So far plant health looks good, but plants generally become susceptible to diseases near or at tasseling as energy has to be devoted to reproduction rather than to an immune response. When scouting and seeing plants that show clearly defined leaf streaking, consult a pictorial guide that shows what the mineral deficiency symptoms look like. In the past there was a good pictorial guide entitled ‘Be your own corn doctor’. The same pictures still apply, and the occurrence of mineral shortages on non-manured fields have consistently increased in incidence and severity. A bit of progress has been made as witnessed by the fact that more fields are receiving sulfur and zinc applications. We need more progress with Mn, Bo, Moly and a few others. If you follow the low stave on the barrel philosophy the greatest ROIs for most growers may come from addressing those minerals other than N, P and K.

As V10 stage is reached in corn fields be observant of the first sign of Goss’s Wilt lesions appearing just above the soil surface. This has occurred like clockwork since 2009. The severity of the disease depends on variety, percentage of B14 parentage, mineral sufficiency, and rainfall amounts. The causal organisms stay in the soil through the years and is a long term threat. Only the BioEmpruv with its mineral and fermentation composition have been found to keep it at bay.

Leaf samples can still be taken and analyzed. The ability to apply identified micronutrient needs with a ground rig disappear for crop producers if they don’t have access to a high clearance sprayer or plane.

Soybean: It has taken a while for bean plants in most fields to reach the V4 – V5 stage. The late arriving heat spurred growth and a portion of the beans are at or near V5 stage where they should start flowering this week.

Earlier foliar applications

Even though most university scientists vouch that foliar fertilizer applications don’t work, record yields and great responses can be coaxed from many crops if a grower can learn from someone who is willing to think differently and has been successful. Doing so is a learning process and requires a person to understand what is occurring within the cells as to their nutritional needs and stresses placed on it by the environment, insects and pathogens. Gaining experience will be a building process. An apt comment is that raising high yield corn is a game of checkers while raising high yield soybean is a game of chess where you are thinking many steps ahead all the time. You will be influencing plant physiology and architecture through your foliar mixes. Adding branches, thus more nodes and pod sites is the first goal after getting the plants to 12-inches tall. Then increasing seed size through late foliars is the goal after R3. I was in Kip’s 154 bushel bean field and shucked enough pods to weigh them on a precise lab scale. His bean size was 1915/Lb. I have plants and beans from the only U.S. bean field treated with Impulse in 2019 and nothing was done after R3 to increase bean size. If he had his yield increase may have dwarfed the final 18 bushel/acre gain .

Japanese Beetles

These pesky critters are back. When digging holes in our asparagus patch 3 weeks ago I unearthed lots of large larvae. We might have to get ready for war with them. A Tulsa company called Trece makes a trap that can be placed at the corners of your property to lure them into your trap’s catch bag.

Dicamba news

So how firm is the June 20th deadline in each state? If you are a person affected, the best source of info and fact is the 1979 research article by Richard Behrens and Bill Lueschens from the University of Minnesota Waseca Station. Bob Hartzler and all other reviews consider that piece as the gospel. With what they found it makes you wonder if the discussions held in St. Louis believed or dismissed those experts due to money.

Larry Steckel is the top weed researcher at the University of Tennessee. He is currently finding Palmer plants that tolerate high rates of both 2,4-D and Dicamba. Look for articles where he is mentioned. If this pigweed specie cannot be controlled, does this force U.S. growers away from a strict corn and soybean rotation? What are your thoughts?

Whatever your post applied products were, be sure to check on each field to see if the broadleaf weeds stayed dead. Taller plants and too much leaf burn from AMS and MSO allow too much recovery.

Nitrogen testing and applications

Corn growers who applied animal or other natural fertilizer and depend on the contained nitrogen may benefit from pulling soil samples to gauge the amount of residual. The three different forms of nitrogen should all be tested for by the lab personnel as well as estimates made of when it will be plant available.

The ‘use it or lose it’ theory exists for nitrate N but not for the ammonia or organic matter fixed forms.

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

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