ISSUE 5 June 1, 2006
One of the most challenging, but rewarding experiences of each season has begun - the crop scouting season. It is the part of my past industry experiences that I miss the most. To be a good crop scout, a person must be observant, open-minded and a bit of a detective.
Look for things that are different. Is the field different from others in the area? Are there areas in the field noticeably better or worse than similar areas in the field? Presence of insects, disease, and weeds should be noted. If there are differences in the field, do they follow natural topographic boundaries, or are they sharply defined? Nature usually doesnít affect crops in straight lines.
For efficacy calls in ag-chemicals or fertilizer problems, look for the inevitable check-strips left by the applicator. It is usually impossible to spray a field without a little gap of some kind somewhere. Look for areas where the fertilizer ran out, or the herbicide was not applied.
Donít forget soil conditions. Although most of our soils are forgiving in the long-term with respect to compaction, spring compaction and its affects on small, weak seedlings can be significant. Bring a spade to the field to determine if some of the symptoms the crop is showing could be related to poor soil conditions.
For possible nutrient deficiencies when the crop is small, plant analysis is of course possible, but it is also possible to determine a cause and solution by applying an appropriate amount of the suspected deficient nutrient (N, or S) and watering it in with a watering can. If the deficient area greens up within 24 hours of your test application, that is most likely the nutrient that needs to be applied to a greater area. If there is no change, you just saved the grower a lot of money.
If non-mobile nutrient deficiency is suspected, a plant sample and soil sample should be taken from the area. Plant samples are notorious for being "on the edge" of critical levels, especially in micronutrient tests. Soil samples often help to solve the puzzle.
Finally, donít forget the NDSU Diagnostic Laboratory. The unbiased nature of the lab could be very helpful in solving sticky problems where one side suspects a human source of a problem and the other suspects nature. Most scouts have taken a lot of training during the winter, but it is nice to have another opinion in important situations.
Dr. Dave Franzen
NDSU Extension Soil Specialist