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CROP WATCH

By Staff | Jun 13, 2014

Last week marked the one month date before July 4, which is when we traditionally like to see corn almost knee high.

In the best growing seasons of the last two decades we have reached that plateau by June 4.

This year most fields are close to reaching that mark near June 10, or about a week later, which is a huge testament to how great the growing conditions of last week were.

While we are on a path that is about a week behind normal, it is so much improved from what happened in 2013 that we all feel quite blessed. The biggest part of the season is still the weather. Always is and always will be.

As said before, this is a year where there is a great disparity between top meteorologists as to what the rest of the growing season looks like to them.

One good source is predicting a strong El Nino to set up just after July 1. Another expects a repeat of 1936 after July 5.

What a few people have picked up on is that there has been a trio of big volcanic eruptions around the globe in just the past 10 days.

They were Mt. Sheveluch, in Russia, which erupted to a height of 32,800 feet, Alaska’s Pavlov to a height of 22,000 feet, and the winning place being Indonesia’s Santiaguito Api to 65,000 feet.

If the volcanic-based meteorologists are correct, the dust from those storms could block enough sunshine to cool the weather 2 to 3 degrees over the rest of the summer.

Such a cool down would be good for depth of fill and the propane men’s billing amounts, but bad for drying costs.

Hail damage

Anyone who wants to get a stark view of what can happen needs to take a tour through Nebraska in an area northwest of Omaha.

I had to travel out there last week to help a few farmers decide what to do with their damaged or destroyed crops. The area seems to be much bigger than what has been reported.

North to south, the damaged area ran from about Oakland Neb. of the north, and close to Lincoln on the south.

The strip of damage extended about six counties to the west. In the worst areas I saw it was tough to tell what crop had been planted unless you were clued-in by last year’s residue.

As of last Thursday, none of the hail companies had sent any adjusters out, because it was justifiably too early.

In many fields a percent of the corn plants had a chance to regrow. But those expectations for regrowth can all disappear with one afternoon of 85-degree weather if a bacterial or fungal soft rot moves down the damaged stalk.

Already we were seeing browning and black coloration to the heart of the pith area in the root crown.

Driving through the heavy-hit towns reminded me of one of the Terminator movies, where people are out on the streets, there is no power, debris and broken glass is all around, and there is little cause for joy.

A pertinent question for irrigated growers is if the parts to assemble, repair, or replace the damaged sprinklers in time to irrigate those crops when the late-June to early-July irrigation season normally begins.

This could have an effect on state corn yields.

Crop development

In last week’s column, the main point I was trying to make on corn development was that while plant growth in most fields was very good, those plants were entering a crucial period.

They were going beyond the V4 stage where nutrient demands are high.

The application of a number of different post-emerge herbicides cause one or more minerals to be chelated and unavailable for the plants’ needs.

Such actions were going to be illustrated by fields that changed from dark green and actively growing to fields that turned yellow, shrunk in size, and go from some of the most attractive to being downright ugly.

That did not happen everywhere, but it happened in enough places that farmers are finally asking questions about it. I’m not sure they are getting the correct answers.

The way I had it explained a few years ago – by a person who was the micronutrient expert at a major university for 25 years – was that the problem is based on the fact that the educational system is teaching, fertilizer retailers are selling, and farmers are essentially utilizing an NPK fertility program at a time when the plants are needing anywhere from 17 to 59 different elements.

Those elements all fill vital roles in the plants functions, from mediating stress to helping form plant parts, to helping to fuel disease defense responses.

There was an illustrated corn pamphlet years ago that was entitled “Be Your Own Plant Doctor” that showed pictures of what each nutrient shortage looked like on the corn plants.

It was a great guide to take to the field and use for diagnosis. What it could not show was how such shortages left the plants, both corn and soybeans, somewhat defenseless in keeping fungi and bacterial invaders out.

In some of those hail-hammered plants in Nebraska, we were finding blackened crown regions in a sizeable percentage of the corn plants.

What experience has taught us in previous hails and responses was that plants can use nutritional support in times when they are under stress and have to recover from such damage.

Plants benefit from those just as much as people and animals do.

When energy supplies, health aids and minerals are applied, once foliage partially regrows, can show positive results.

Understanding the role of each mineral also requires learning what minerals are mobile or immobile in the plant and if they accumulate most in new or old tissue.

Nitrogen

In many second-year corn fields there is uneven growth and yellowing. Form and timing of nitrogen seems to make a big difference.

In some cases, fall-applied 82 percent has looked like crap, which is unusual. Planter-applied nitrogen, along with placed N or AMS looks great.

The reason for the poor 82 percent results seems to be related to the amount of undecomposed residue causing microbes to tie up the N in meeting their carbon-to-nitrogen demands.

The best course of action may be to side-dress with a stabilizer and place the band below the residue layers.

Growers need to be aware that yellowed corn does not always mean an N shortage.

If zinc, copper and magnesium levels are low in the plant, they will suffer from poor nitrogen utilization.

Applying more N in those cases will not solve the problem. If hilltop plants begin to yellow when rainfall is adequate, it is likely not a loss of N.

Weed control

In last week’s article, I must have typed wrong and said that more farmers are moving back to post-emerge herbicides. I meant to say they were returning to a pre-emerge residual program using foundational products.

In fact the new coined term is “overlapping residuals,” which is where there are more than just a preapplication.

Most of those products have varied modes of action and growers want to keep multiple modes in effect to minimize the number of weed and grass escapes.

They recognize that such a program will likely cost more, but they have learned by experience what not getting control will cost them.

I ran across a weed I did not recognize while I was in the Carroll area on Monday.

I dropped it off with a retailer who had the Nebraska weed guide so he could hopefully ID it. Don’t be afraid to do the same.

The more we can prevent new introductions from reproducing, the cheaper controlling such weeds in the future will be.

Everyone growing crops needs to do the same if something out of the ordinary shows up.

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

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