What’s Missing? Three Basic Tools for Diagnosing Nutrient Deficiencies


Diagnose nutrient deficiencies correctly to treat the real problem

The best approach to treating nutrient imbalances is a preemptive one, because symptoms of nutrient imbalances frequently show up long after irreversible cosmetic damage has occurred. Establishing a well-balanced nutrition program from the start gives plants the best chance for healthy growth and disease/pest resistance. When problems do arise, accurate diagnosis is often difficult because symptoms of nutrient imbalances mimic those of disease, and vice versa. Damage from other environmental stressors, such as insects, pesticides and pollution often adds to the confusion. Obtaining an accurate diagnosis is a three-fold process involving visual observations, plant tissue analysis and soil testing.

Visual Observations

Plants with inadequate nutrition exhibit visual cues that are indicative of certain nutrients. For example, stunted growth and uniform chlorosis are signs of nitrogen deficiencies. Interveinal chlorosis may denote the absence of iron, or a reddish-pigmentation may indicate a need for magnesium. Familiarity with the growth stages and appearance of healthy plants is necessary in order to read visual signs correctly. For instance, variegation or a reddish-color on the leaves may be characteristic of specific plant species.

While visual analysis is a useful tool, it is not conclusive. Plants may be suffering from multiple deficiencies or visual symptoms may not be the result of malnutrition. An accurate diagnosis is best achieved when visual observations are used in conjunction with plant tissue analysis and soil testing.

Plant Tissue Analysis

Plant tissue analysis can often detect nutritional imbalances before visual symptoms are present. Plans can then be made for early intervention, before the problem spirals out of control. Test results can be used to access the efficacy of existing fertilizer programs. Tests also indicate the nutrient levels available at the time the sample is taken; this is important because nutrient levels fluctuate throughout the growing season. Be sure to take samples at different stages in a plant’s life cycle for proper analysis. For comparison purposes, samples from both healthy and damaged plants are helpful. Plant tissue analysis is not meant to be used in isolation, but rather in combination with soil testing.

Soil Testing

Soil tests indicate soil salinity, acidity (pH) and fertility. Prior to planting, they are useful for predicting lime and fertilizer requirements. Tests are especially useful for the detection of toxicities. Nutrient uptake is greatly influenced by soil composition and acidity (pH). For example, iron and zinc are more accessible at low pH levels, whereas calcium and potassium are less accessible. Be aware that soil analysis does not indicate if plants are able to utilize available nutrients. Continual sampling throughout the growing season is a good way to fine-tune fertilization programs.

When used in combination, visual observations, plant tissue analysis and soil testing are powerful tools for accurately diagnosing nutrient deficiencies. Once a nutrient problem is correctly identified, fertilizer treatments can be adjusted accordingly. KeyPlex offers a wide range of highly effective plant nutrition products for crops such as tomatoes, potatoes, carrots, cole crops and more.

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