Blossom End Rot (BER)

A physiological disorder of a plant during the stage of fruit development and growth. It is a quite common problem on tomato, pepper, eggplant and zucchini which is caused by the (usually transitory) low calcium concentration in fruits. The disorder appears most commonly in cases where watering is irregular or in periods of drought and plant stress which induce the transitory decline in calcium absorption and movement in the plant.

Calcium deficiency can also appear during fruit development due to excessive fertilization with nitrogen and high temperatures which favor fast development of plants, high salinity and root damage during soil cultivation.

Most of the times BER appears on the first tomatoes of the season as plants under stress at fruit set of the first inflorescence. Usually the problem disappears later in the season, on tomatoes of subsequent inflorescences.

How you can avoid BER

– Select varieties tolerant to the disorder
– Water plants adequately and regularly
– Mulch plants so that water evaporation from soil in minimized
– Keep soil pH between 6.5 and 6.8
– Use fertilizers poor in nitrogen and rich in phosphorus
– Add calcium to the soil at planting, but only if calcium deficiency is proven. Usually calcium level is adequate in soil but it cannot reach fruits for the reasons explained above
– Spray foliarly with a calcium fertilizer

Author/Photos: Aris Chloridis