Stop Guessing: Diagnose the Crop Problem Before You Spray

A poor diagnosis turns a crop problem into an expensive spray problem. Yellowing, wilting, leaf spots and stunting can come from pathogens, insects, nutrient imbalance, salinity, herbicide injury or irrigation mistakes. Several causes can look almost identical.

Before you spray, make these five checks

Look at the pattern. A problem following irrigation lines, wheel tracks or spray passes may be environmental or application-related. Random plants or expanding patches may point toward a living pest or pathogen.
Compare affected and healthy plants. Check leaves, stems and roots. A leaf symptom may begin with root damage, poor drainage or a stem infection.
Review recent events. Note rainfall, heat, cold, fertilizer, pesticide applications and irrigation changes. The timing often narrows the cause.
Photograph the whole problem. Take one field-wide image, one plant image and close-ups of symptoms. Include healthy plants for comparison.
Submit a useful sample. Choose plants at the edge of the affected area—not plants that are already dead and decomposing. When possible, include roots and growing medium.

Why this saves money

A fungicide cannot correct salt injury. Fertilizer will not cure a vascular wilt. Repeated insecticide applications will not solve damaged roots. Confirming the cause prevents unnecessary treatments and gives the selected product a fair chance to work.

Bottom line: scout first, record the pattern, inspect the roots and confirm uncertain problems through Extension or a diagnostic laboratory. Good crop protection begins with the right diagnosis.

Sources: University of Minnesota Extension diagnostic guidance; Penn State Extension: Diagnosing Poor Plant Health.

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Featured photo: Ali Nurmemmedov via Unsplash.