Harmful viruses on stone fruit crops and sanitation methods

Abstract

Relevance. Viral diseases can significantly reduce the yield of stone fruit crops. More than 30 viruses have been characterized on stone fruits crops, among which the most harmful are Plum pox virus (PPV), Prunus dwarf virus (PDV), Prunus necrotic ringspot virus (PNRSV), Cherry leaf roll spot virus (CLRV), Apple chlorotic leaf spot virus (ACLSV). Viral diseases monitoring is essential for controlling the viruses prevalence and choosing a control strategy. In the absence of healthy plants of a certain variety, health improvement is carried out using laboratory methods, including thermotherapy. Sanitation methods need to be improved in relation to the culture characteristics and the virus type. Of considerable interest is the development of techniques that reduce the viruses concentration when growing stone fruit trees in the field.Methods. During 2016–2020 using the ELISA (“Loewe” diagnostic kits) diagnostics of viruses on varieties and clonal rootstocks of cherry, sweet cherry and plum (660 plants) was carried out in the conditions of the Moscow region. For plant health in 2019–2021 used thermotherapy for 3 months. To study the effect of Pharmayod (“Farmbiomed”) on viruses in open ground, 24 plum plants of 5 varieties were treated with this drug at a concentration of 0.3 ml/l.Results. The total prevalence of viruses on cherries varieties was 44%, sweet cherries — 40%, plums — 59%, on clonal rootstocks — 46, 55 and 56% respectively. The highest incidence of PNRSV and PDV viruses has been established. Cherry plants of 11 varieties, free from the main harmful viruses, 4 varieties of sweet cherries, 12 varieties of plums and 9 forms of clonal rootstocks were revealed. The use of the Pharmayod on plum trees in the open field contributed to a decrease in the infection index of the studied viruses. Plum plants in a heat chamber were characterized by a higher survival rate and growth parameters in comparison with cherry and sweet cherry. After the completion of thermotherapy, a significant decrease in the index of infection in plants was noted.