NC State Extension Publications

Problem

Nutritional disorder – magnesium (Mg) deficiency

Symptoms

Older leaves initially develop a marginal leaf chlorosis which later progresses to a tanning or darkening coloration along the outside leaf margin. As symptoms develop further, the interveinal chlorosis expands inward on the leaf and the dark discoloration spreads between the veins. With advanced symptoms, the entire leaf can become necrotic. In addition, fruit color appears pale, but fruit size is normal.

Initial magnesium deficiency on the lower leaves.

Initial Mg deficiency on the lower leaves.

Brian E. Whipker

Initial magnesium deficiency on the lower leaves.

Initial Mg deficiency on the lower leaves.

Brian E. Whipker

Intermediate Mg deficiency symptoms.

Intermediate Mg deficiency symptoms.

Brian E. Whipker

Advanced Mg deficiency symptoms.

Advanced Mg deficiency symptoms.

Brian E. Whipker

Intermediate Mg deficiency symptoms.

Intermediate Mg deficiency symptoms.

Brian E. Whipker

Advanced Mg deficiency symptoms.

Advanced Mg deficiency symptoms.

Brian E. Whipker

Advanced Mg deficiency symptoms.

Advanced Mg deficiency symptoms.

Brian E. Whipker

Advanced Mg deficiency symptoms.

Advanced Mg deficiency symptoms.

Brian E. Whipker

Similar Problems

Potassium deficiency, sodium toxicity, drought stress, and wind damage may produced similar symptoms.

Additional Information

Because symptoms can occur due to many possible causes, it is important to determine the actual cause. Tissue testing will help identify any nutritional disorders. Reviewing the weather history and growing conditions will help to determine if that is the cause. It is also useful to note that weather related problems will be more prevalent over a wider area of the field and will develop quickly. Nutrient deficiencies usually take weeks to develop.

Diagnostic Tips

Take a soil sample to determine if nutrient levels are inadequate. Submit a leaf sample for nutrient analysis. The sufficiency range for magnesium in strawberries is between 0.25 and 0.5%. Values below 0.25% are considered deficient and above 0.5% are considered excessive.

Corrective Measures

Take a soil and tissue test to determine nutrient levels. Make adjustments based on those test results and the lab’s recommendations.

Management

Conduct a soil test prior to planting the crop to determine if pre-plant fertilizer applications are required. Fertilizer can also be injected to the crop during active growth. Recommendations vary by soil type and your location, so check with local resources for guidelines.

Funding Sources

Funding was provided in part by the National Sustainable Agriculture Program: Sustainable Strawberry Initiative and the following sources.

A thank you is also expressed to Kube Pak of Allentown, New Jersey for donating strawberry plants.

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Author:

Professor
Department of Horticulural Science

Publication date: April 24, 2014

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