By Jennifer Olvera, Garden Guides Contributor
About Blossom End Rot
Blossom end rot is a problematic disease that affects both
commercially grown and homegrown tomatoes, causing severe crop
loss.
Prevention and Control
Prevention of blossom end rot depends on maintaining adequate
supplies of moisture and calcium to developing fruit. Tomato plants
should neither be too hardened nor too succulent when planted and
should be planted in well-drained, aerated, warm soil. Mulching
soil helps maintain adequate water supply when moisture is at a
premium. In home gardens, shading plants during heat is
beneficial.
Use a fertilizer low in nitrogen but high in superphosphate, such
as 4-12-4 or 5-20-5, to treat blossom end rot. Foliage can be
sprayed with calcium chloride solutions, but extreme caution is
required since calcium chloride is phytotoxic if applied too
frequently or in excessive amounts.
Affected Plants
The disease does not spread from plant to plant or fruit to fruit.
Blossom end rot most often affects tomatoes but also can affect
peppers, squash and watermelon.
Damage
Symptoms appear on the blossom end of the fruit. Blossom end rot
appears as small, water-soaked spots that get bigger and darken
quickly as the fruits develop, covering as much as half of the
fruit's surface. The spots dry out, becoming flat, black and
leather-like in appearance and texture.
Natural Insecticides
Fungicides and insecticides are not helpful in treating and
preventing blossom end rot.
Other Methods of Control
Lime soil to pH 6.5 to 6.7, and be sure to fertilize correctly. In
home gardens that have not been soil tested, 5 pints of 8-8-8 per
100 feet should be worked into the top 8 inches of soil. Mulch
around plants and make sure tomato plants get 1 1/2
inches of water weekly. Plants also can be sprayed with calcium (4
tablespoons per gal of water).
