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Keep ahead of nature’s curveballs

In mid-May, most of the corn in Iowa was finally in the ground, and we were off to a good start with soybean planting for 2011. But weather has challenged our crop emergence and crop growth this year, putting the planting and spraying well behind schedule. As a result, we may be in for some bumps down the road this growing season.

“Challenges” is my nice way of saying we had better be watching for some curveballs that Mother Nature almost always throws our way. In baseball, the keys to hitting a curveball are preparing before you step into the batter’s box and recognizing the pitch when you are in the box. The keys to hitting Mother Nature’s curveballs are the same.

Crop scouting is all about being prepared before you step into the box — your fields -— and recognizing the challenges you find when scouting. 

5 steps to scouting

To stay ahead with scouting, keep this in mind. Effective crop scouting boils down to about five basic steps:

1. Sample multiple areas of each field to get accurate estimates of crop populations, growth stages and health.

2. Identify crop pests, densities and growth stages.

3. Diagnose causes of crop injury and related symptoms.

4. Compare the pest pressures and crop injury that you can see to recommended economic injury or threshold levels to decide if you need to treat or take action.

5. Repeat these steps at regular intervals (I suggest weekly) throughout the growing season.

Tools to take with you

Before you start scouting your fields, get the right tools (preparation) to hit those curveballs:

Notebook to record where and when you scout, the crop stages and weather. Your local agronomist might have scouting forms to use. Flags quickly get hard to find, so it’s not a bad idea to use your GPS-enabled phone to get an accurate location on areas you want to spot-check again.

Spade or trowel to dig up plants to observe roots and rooting patterns.

Field scouting guides, which contain details on crop staging, pest identification and herbicide injury or disease symptoms. ISU Extension has developed a series of handy, portable field guide booklets covering corn, soybeans, weeds and pests.

Tape measure to determine crop and pest sizes and stand counts.

Plastic baggies to collect plants or pests to take to an agronomist for identification.

Knife for slitting plants open to look for disease or injury.

Pocket digital camera, or use your cell phone camera if it takes quality images. Agronomists appreciate pictures of potential problems, like an overview shot of an affected area or close-ups of symptoms.Armed with the right tools and knowledge, you can head to the field with confidence.

I’ll admit that early in the season, riding an ATV is a more efficient way to cover fields. But, especially as the season progresses, walking lets you see more (and is good for your health).

You don’t have to walk the whole field. Just try to hit enough areas to scout accurately. Eight to 10 stops scattered across representative areas of a field is a good start. At each stop use your tools and go through the key steps.

Practice makes perfect

Since crops this year are up and growing for the most part by now, we won’t dwell on the details of what to watch for at emergence. Hopefully, many of you started your field scouting trips as the crop emerged and have some initial impressions of the early-season health of your crops.

But just like a baseball player at bat, where it doesn’t take long to go from being ahead in the count to being in deep trouble, crop conditions and pest problems can quickly get out of hand. That’s why we recommend regular weekly scouting for at least the first half of the season. Often, not all the scouting tasks need to be done on every trip, so it isn’t as daunting a task as we agronomists may make it sound.

Steps to better management

Besides watching for insects, weeds and diseases, you can take a few extra steps and fine-tune your crop management:

Observe your crop stand for consistency of growth stages, plant heights and plant spacing. If you notice inconsistency, look for patterns that may indicate planter configuration, sprayer overlap, tillage, drainage or soil differences.

Do some digging to double-check planting depth and the condition of the seed trench and root systems of your crops. This can give clues to the performance of your planter and row attachments.

If you can carve out the time to scout fields throughout the growing season, your crops may be “telling” you quite a bit. They may even tell you what you can do to make the rest of the season –- and subsequent growing seasons –- more successful. Go hit those curveballs.

McGrath is partnership program manager of ISU’s Corn and Soybean Initiative.

New game plan for resistant weeds

I don’t typically consider weed issues to be much more than a fastball down the middle of the plate. We identify them and “hit” them with our herbicide package of choice — and game over. But Mother Nature has come up with a better pitch.

Herbicide-resistant weeds have been around for decades, but more recent developments, such as glyphosate-resistant giant ragweed, marestail and waterhemp, have changed the game. This is where good scouting of fields and accurate recordkeeping can help raise our batting average.

Note your weed escapes from herbicide applications. If you have weed escapes from glyphosate once, we can often point the finger at uncooperative weather, too low of an application rate, poor coverage, improper adjuvant selection or other variables.

If you have a more consistent record of weed escapes from glyphosate, then we probably better treat the weeds as glyphosate-resistant. As an ISU weed scientist once told me, “if it walks like a duck, and talks like a duck, treat it like a glyphosate-resistant duck.” — Clarke McGrath

This article published in the June, 2011 edition of WALLACES FARMER.

All rights reserved. Copyright Farm Progress Cos. 2011.