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CROP WATCH

By Staff | Jun 3, 2011

Wham! Spring is over and summer has arrived. Last week we were still wearing insulated sweat shirts and jackets and this week we began with 90-degree temps and 40 mph winds.

That made it one nasty day to be outside and an even worse day to be in the fields. In many we saw the beginnings of miniature sand dunes being formed.

It just makes you wonder which meteorologist is going to be closest with their guesstimate. Will it be Elwynn, Acker or Bastardi?

For me I prefer the guys who are brave enough to go out on a limb rather than make their predictions in terms of being just a little bit drier, wetter, cooler, or warmer than normal.

So far those three seem to be on the same page in predicting a cool and wet extended spring followed by lots of hot and dry weather for the Midwest.

Here in central and northern Iowa many farmers have a better-than-average crop if things are a bit on the dry side early, as long as rainfall is plentiful in August.

Marketing correctly is going to be a difficult task this year as prices could swing more in either direction than they ever have.

Growers sure hate the thought of selling too early and cheap. Most grain elevators hate that thought as well as their margin calls in 2008 made even the bravest look for cover.

What one event could come at us from out of left field that could spill our house of cards? We know that the fundamentals are hugely in the growers’ favor

But our knowledge and trust in fundamentals has often been our downfall as large economic events can sway the markets more. Stay tuned.

Field happenings

As of this weekend the soil temps in central and northern Iowa 2 and 4 inches under heavy residue was still close to 50 degrees. Too many nights under 50 and even 40 don’t contribute to fast warm-up. I used Sunday’s warmer temps to finally get our tomatoes in the ground. The coolness of the soil surprised me as it had been warmer several weeks ago.

The net effect of the cool soils and sunless sky was that most of the corn that had gotten planted either in mid-April or during the first two weeks in May had stalled out in the V2 leaf stage.

While we had often seen corn reaching nearly knee high by June 4 in recent years, that goal didn’t seem even remotely possible this season. Slow growing corn equates into corn plants that are later to tassel, silk, black layer and reach harvest moisture.

Such slow growing corn is also more susceptible to soil pathogens that like to invade root tissue and cause stalk and yield problems.

The expected heat for the week turned into a reality and much of the corn was pushing into the early V4 stage at a rapid pace.

What may have happened is that top growth stalled, but root growth continued, hidden from our walk by observing. Now the top growth is playing catch-up.

A week from now there could be lots of fields pushing into the V6 stage and adding inches at a rapid pace.

Having the corn develop at a rapid pace now is important in meeting yield goals. The sooner it gets into the taseling and silking stage the shorter the corn stays, the more likely it is to flower before moisture reserves are used up, the longer the days are during grain fill, and the more likely the grain is to reach preferred grain moistures early in the fall.

So far most of the beans in central Iowa are still only reaching the unifoliate growth stage. We typically expect several trifoliate leaves to have developed on early plants by June 1. If Friday is June 3 and flowering is supposed to be triggered by June 21 holding the longest sunlight hours of the year, then all the bean plants will have to hustle to form enough podded nodes to produce the desired yields.

Late-planted beans always face the task of forming the 17 to 19 nodes needed to generate 60-plus bushels per acre.

So anyone who is managing for top bean yields may have to make early-season corrections to do what is needed to force more rapid node formation and additional branching.

Do the math now and adjust or face the fact that the bean crop is several leaf stages behind where it should be.

The top operators will be those willing to think and operate outside the box this season. Will you harvest 25 Bu/A SDS beans or reach into the high 60 or 70 Bu/A category as many innovative producers did in 2010?

Early season insects

Thus far not many insects seem to be causing problems with our two major crops. There have been low populations of flea beetles found in central Iowa.

They are easiest to find early in the afternoon on warm and calm days. How many of those have we had? You have to scout for the rasping type feeding on the leaves of the corn plants.

In some of the corn-on-corn fields the earliest signs of stink bugs having pierced and sucking the stalks are becoming apparent.

Those plants look more like pineapple plants with fasciated tops and dead apexes. Thus far those fields with heavy residue are showing the most damage, which is still less than 5 percent.

Can we scout, dig and find enough of the pest to get an accurate count? Will we see the very damaging brown marmorated species in those fields or will they remain in the eastern states?

Black cutworms remain light in the area that I have scouted so far. One has to look for plants that are either cut at ground level or wilt down from the center on warm afternoons.

With fewer acres being true no-till and holding high populations of winter annuals they should not be a large factor.

Bean leaf beetles seem to be scarce so far. The early feeding on volunteer bean plants in the corn fields is present, but at reduced levels compared to other years.

There have now been enough growing degree units to force most of the beetles from their over-wintering cover and into the crop.

So with most of the bean fields being planted in such a short time, the invaders have been spread out over more fields rather than concentrating in just a few early-planted ones.

Plant stands

So far corn stands look good from the road. Once you get out into the fields and start counting skips it is apparent that a few things were at work.

The first is that operators who used the 20/20 monitors found that the looser soil slowed the driven wheel and effectively cut the dropped populations by about 2,000 seeds per acre.

So they adjusted their drop upwards to hit their targets.

In many of those blanks one can still find the roped up plants that could never find the surface.

Was it cold water imbibitions that caused tissue damage? Was it soil that was too loose or let light penetrate deeper into the soil than normal? Was it the wide swings in soil temperatures as the daily highs jumped from the mid 50s to the upper 90s?

We saw what appeared to be seeds that sprouted a week later than their neighbor’s in the same row due to being placed into dry soils. Why did the moisture not move upward to imbibe the seed?

Thus far I have not heard the silver bullet answer to what happened this season. We will have to see what the effect on yield ends up being.

Weed control

Every year we see that the weeds and grasses observe thermal windows that open and close at varying times each year.

What this means is that most grasses and broadleaves prefer a certain range in temperatures in which to begin and end germinating each year.

Those windows were better adhered to before woolly cupgrass and waterhemp moved into Iowa. If the final tillage is performed after the window closes the considered field may stay fairly clean the rest of the season.

The trick in using this information may be to incorporate this knowledge when building any residual herbicide plan.

We are seeing this year that the Amide herbicides have given very good grass control if they were used at sufficient rates.

If this control lasts another three weeks we should see ground shading occurring, which is a great tool to keep continued weed emergence and growth under control.

In another month we will be able to compare notes on which products worked well, which ones needed to be supplemental with partial respray, and which ones failed.

Doing it now may lead to incorrect or premature conclusions.

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

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