Nutritional disorder – sodium (Na) toxicity
Lower leaves with necrotic spotting, followed by the development of a marginal necrotic band. Under severe conditions, symptoms can spread over the entire leaf and also develop further up the plant. Plant growth can be stunted.
Leaf necrosis symptoms also occur with boron (B) toxicities.
Typically excess sodium levels come from the irrigation water. Test your water supply for nutrient levels.
Submit a leaf sample for nutrient analysis. Values above 0.1% (1000 ppm) would be considered excessive.
In the short term, it is difficult to correct excess levels. Damage to the plants cannot be reversed. Overhead irrigations my help leach some of the sodium out of the root zone (but irrigations need to be managed to avoid gray mold).
Sodium can be leached, especially in sandy soils. Determine the source of sodium in your system and try to eliminate it. Change irrigation water source if possible.
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.
Publication date: April 23, 2014
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