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CROP WATCH

By Staff | May 11, 2012

With the month of May just a week old we seem to have gotten the biggest monkey off our backs. The previous burden was the lack of subsoil moisture across most of the western Corn Belt.

Before this, the latest Palmer Drought index maps much of the northern and western parts of Iowa, a good portion of Nebraska, and most of the crop growing region in Minnesota were in a moderate-to-severe drought situation.

Experience and proof from previous years showed that unless the moisture situation changed the chance of achieving trend line yield levels were slim to none unless very timely rains fell during the season.

In Oklahoma they say, “it always rains at the end of a dry spell.” So we got our rains and tile lines are running again in areas that had gone dry since early July. Now we have a fighting chance to have a good crop. It appears that a repeat of 1988 can now be averted as the La Nina seems to finally be over with, at least for now.

Decent weather

No one has uttered the phrase “I wish it would quit raining,” yet, but it would be nice to have four to six good dry days to get the fields into planting condition and be able to run the planters in order to reach the 95 percent planted range within the three-state area.

Then if most of the corn acres end up being planted by May 10 growers feel they can achieve maximum yield potential on those acres. For all the expense involved with planting a corn crop, expecting anything less seems like wasted energy and potential.

The temps have to begin to warm into the 70s once more to get the crop emerged. Then we can evaluate the stands and the need to address any problems. The few weeks of cooler-than-normal temperatures have slowed growth and left many of the stands, where observable, looking yellowed and appearing to lack much energy.

In time that warm-up should occur and the corn plants should be on their way to pollinating by mid-July. It would also mean that the majority of growers could then make progress with planting the bean crop.

With $14 per bushel beans on the horizon most growers would love to have their beans planted by the time soil temps finally climb upward.

Poor stands anyone?

The major focus of all growers is to run the planters as many hours as humanly possible. Once the major crops are planted on each farm, the next task will be to tour fields to see if a high enough percentage of each field will have a stand worth keeping. So far most stands look good.

We still have to wait a few more days to judge the majority of the fields and how they emerged can be rated. As always the first priority is to get all fields that are ready planted for the first time, then begin replanting any acres that require it.

There are several published guidelines that can be followed if needed. These typically give the percentage of optimum yield that would be obtained given the different existing populations versus the original targeted populations at different planting dates.

If there is any question about leaving a stand versus tearing the old one up and redoing it, the calculations need to be made to clearly show that spending the extra money and time is going to be repaid with expected higher yields.

Given the early May date that we are now at, if any field population is not in the mid- to high-20s, or has very erratic spacing, it may have to be judged harshly. The expected higher value of the crop reaffirms that last caveat.

Early growth

So far what seems to be evident is that the stands from the first planting after April 10, the insurance date looks good, but some of those planted just in front of the cold rain on May 4 seem to have had a few problems. That would likely be a case of the cold water inhibition that has been researched extensively and has been a constant in recent years.

Those fields planted during several two- to three-day windows during late April are generally looking very good. Growth has been slow due to the cool temps and cooler nights, but heat and sunlight should help rectify any problems.

The recent rains have been great for filling the subsoil profile. Realize though that the early soil warm-up this season would have allowed a higher percentage than normal to convert from the non-leachable ammonia form to the leachable nitrate form.

Thus a portion of the fall-applied nitrogen is at risk of being leached deeper than the 30 inches that is normally considered the maximum depth from which corn extracts N. Having or being able to use a spad meter to check yellowing fields could be important this season to verify that foliar symptoms reflect true in-plant shortages.

Bug expectations

We have talked about the expected insect feeding to occur at greater levels this spring, partly due to the warmer winter leading to greater survival. One insect and vectored disease that could occur would be the corn flea beetle and accompanying Stewart’s wilt.

This could be called a cousin of Goss’ wilt. It was a threat about eight years ago when we saw heavy flea beetle populations invade fields of V1 to V2 corn plants. More damage and disease vectoring was expected than what actually appeared. There were quite a few acres sprayed as the flea beetle populations reached high levels.

In the end it appeared that a high percentage of the popular hybrids possessed a good level of disease resistance.

Some entomologists are still expecting high populations of different white grubs. These could feed on many different row crops, hort crops and turf, especially near buildings or yard lights, and possibly near tree lines.

Applying a planting time insecticide or top-dressed planter box product might still be the best remedy for this problem.

A good and pertinent question is, “What should we expect for corn rootworm feeding problems this spring?”

Normally eggs generally hatch after 625 growing degree units have been accumulated, which is normally sometime in early- to mid-June. With the ground warming up early this year and the corn planted late in comparison, larvae will go hard after small plants or develop another strategy to gain their nutrition.

Everyone can have their own opinion on what they will do, but we may just have to see what happens. Fields that held significant populations should be scouted and dug regularly to make sure no corn root worm populations become severe.

In cases where a damaging level of feeding has been detected, the alternative treatment choices are few to none. We have seen good results and a cessation in feeding when applying Safe Strike to the foliage.

People are still noticing lots of moths in the vegetation and around buildings. Many of these have been identified as armyworm moths. The moths are going to try to lay eggs in any grassy margins or waterways.

In prior years and in other states these larvae have proven to be heavy feeders on grasses in those areas of crops bordering any grass strips. They should not be a serious problem, but definitely do not forget about them.

Wheat breeding

It was announced this week that Bayer Ag will be opening a large wheat breeding station near Seward, Neb. This should be a plus for the community and mean that a major European firm is stepping up and is intending to fill some of the gap left when many universities stepped away from public wheat breeding programs.

Small grains are still a big item in Europe as well as on the continents of Australia and South America. With the scary UG99 wheat rust on the horizon and the potential present for major acreage losses occurring as it spreads, ramping up production capacity and developing improved varieties will help producers in many states and countries.

Again the issue of food security includes a lot of focus on wheat, even if the acres within the U.S. and in the Corn Belt have decreased in recent years.

Managing weeds

Be sure to keep scouting each field to see how the weed control is measuring up to expectations. With the many admonitions from Delta State weed specialists and farmers about how their weeds have become uncontrollable with the current total post programs and complete reliance on non-residual products, everyone needs to stay vigilant.

Products need to be applied at sufficient rates and on time. I think we have learned that if a patch of weeds looks like it has not been sprayed, but you know for sure that it was, then repeating the application and not checking the spots for a few weeks is not the thing to do.

Get out there and dig, look for symptoms and see what may have led to any failures. Escapes need to be dealt with by using different mode of action products and a developing a thorough explanation for any control failures.

Good luck with your planting progress.

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

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