Input and fertilizer costs are soaring. Weeds that could once be easily killed are now using their resistance to attack plants. New insect pressures emerge every season. There’s never been a more critical time than now for in-season plant tissue analysis.
A corn tissue test is a report card on the health of your plants, giving you a picture of how well your crop is developing and identifying areas that may need improvement. In conjunction with a soil testing program, plant tissue analysis provides the diagnostic information you need to get the most out of every plant.
When to Sample
Every lab operates differently regarding submission requirements, so check with your designated institution for the specifications. But a good rule of thumb to follow for collecting samples includes:
Collect early enough so information can be used in the current season.
Collect again at the end of the season to evaluate the crop and identify adjustments needed for next year.
At a minimum, test at the V4 or V5 stage, and when the crop reaches V9.
Test again at early tasseling or silking.
What to Sample
Reliable testing requires collecting different parts of the plant at additional reproductive steps. Before the V5 stage:
Take the entire plant, cutting the stalk off as close to the ground level as possible.
For corn that's more than 12 inches tall but hasn't yet tasseled, sample the first fully developed leaf, cutting it off at its base where it joins the sheath.
For tasseled corn, collect the leaf below the top ear, cutting it off where it joins the base.
How to Sample
It’s essential to collect random samples and there are several ways to accomplish this:
Walk through the fields and collect samples randomly.
Set up a grid and collect a sample from each area.
Throw a hula hoop into the field and collect that sample. Repeat your throw.
Gathering 20 or more random samples is usually sufficient to paint a picture of overall vitality.
Problem areas are, well, problem areas. Suppose you identify a section of the field that seems to be suffering from a nutritional deficiency or weed/insect pressure. In that case, you’ll want to take multiple samples from this area, as well as soil samples, and submit them separately for analysis. If you’re collecting random samples, avoid any diseased or damaged plants, as they can throw off the results.
How to Evaluate Results
First, don’t panic! For instance, it’s important to remember that nutrient sufficiency ranges only to provide general guidance on what concentrations of nutrients should be visible. And these concentrations are not static; they can change throughout the day or season as the plant grows. You’ll want to consult with a professional agronomist or crop advisor before making any wholesale changes.
If you have fields that look normal but have some areas with poor stands, weak plants or symptoms that could indicate undue stress from insects or weeds, tissue sampling can offer you answers—and even better—potential solutions.
Learn How to Unlock Nutrients
Generate® stimulates native soil microbes to unlock nutrients that would otherwise remain unavailable to the plant. Learn more about how we got 8% more nitrogen in the soil available to the plant using Generate.