Institute of Soil Science, Agro Technologies and Plant Protection Nikola Pushkarov, 7 Shosse Bankya, 1331 Sofia, Bulgaria
Abstract. Tomato is one of the economically important crops in Bulgaria. Low tomato yields in the country are mostly due to lack of knowledge on sustainable agronomic practices, lack of improved varieties, which are well suited for high yield and resistance to diseases, and also due to damage caused by pests and diseases. Many viruses infect the tomato crop. The object of this research was to identify viruses infecting tomato crops in Bulgaria. The presence or absence of a viral infection in tomato plants was carried out with DAS-ELISA serologic assays with specific polyclonal immunoglobulin G for the relevant plant virus. Most of the tomato plants were infected with one or two viruses and in rare cases with more than two viruses. We found that mixed viral infections caused more severe necrotic damages in the tomato fruits and increased the economic loss compared with mono infections.