Considerations on some polytunnels soil characteristics that favor the non-parasitic disorder blossom-end rot on tomatoes

Abstract

Blossom-End Rot is a non-parasitic physiological disorder found in tomatoes, peppers, eggplants, and some melons. It occurs due to a low level of calcium in soil and high fluctuation of available water .Thus, a calcium deficiency occurs during fruit maturation, which lead to lesions. The affected area can cover up to half fruit. This disorder can also occur when there is an excess of calcium in the soil. Most of the water is lost by evapotranspiration and the calcium accumulates into the leaves. Fruits do not transpirate as much as leaves, so less calcium is stored in the fruit, resulting in a calcium deficiency in fruit. Another favorable factor is over-fertilization with some nutrients. One of the objectives of the paper is the soils characterization on which have been identified plants affected by Blossom-End Rot. It were studied greenhouses and polytunnels soils from several locations (Barlad, Spataresti-Falticeni, Bacau) in North-Eastern Romania. Following the investigations, it was found that the symptoms on tomatoes were not due to a parasite action. In the areas where Blossom-End Rot was identified, soil profiles were developed and analyzed. In the laboratory were determined some properties of soil samples taken. The analytical data obtained in the laboratory reveals that this disorder occurs on soils with a coarse texture, sand and loamy sand soils, moderate acidic, with a very low acidification buffering capacity, located in the marginal areas of the polytunnels. The correct identification and differentiation of Blossom-End Rot from gray rot caused by the pathogen Botrytis cinerea, presents a particular practical importance in order to establish prevention measures and cultural recommendations