SZTE researchers develop microbiological preparations for efficient walnut production

According to the statement, the traditions of walnut production and the use of walnuts go back centuries in both Hungary and Turkey. In recent years, the destruction of walnut trees has become increasingly spectacular, due to the explosive spread of the invasive walnut shell borer, which has been caused by the emergence of previously unidentified pathogenic microorganisms, as well as the spread of various bacterial and fungal species that cause indirect damage due to the weakening of the trees’ resistance. Walnut trees may disappear from gardens completely within a few years.

Only large-scale chemical solutions offer an acute solution to the situation

However, chemical pesticides used against bacterial and fungal pathogens of walnuts and their residues enter the food chain, therefore there is a growing demand for alternative, environmentally friendly control strategies based on the use of microorganisms that have a beneficial effect on plants. One of the main limitations of the agricultural application of beneficial microorganisms is the variable field efficiency. One possible strategy to overcome this is the development of biological preparations that contain not only one, but also several beneficial microorganisms. The consortium established by the Department of Biotechnology and Microbiology of the University of Szeged, the University of Sopron and Pannon-Trade Kft., together with their Turkish partners, is developing a complex, environmentally friendly process based on several microorganisms that is capable of offsetting the economic losses resulting from bacterial and fungal damage in walnut production. The experts want to develop prototypes of complex preparations and test them in nursery gardens that provide protection against microbial pests of walnuts and allow for a reduction in the use of chemical pesticides. During the research, soil and leaf samples and walnut shell drilling mixtures are collected from walnut plantations severely and less affected by damage from microbial pathogens. This is followed by the determination of the physicochemical parameters of the samples, followed by the isolation of pathogens and beneficial microorganisms using selective media and their DNA-based identification.

The strains are placed in the Szeged Microbiological Strain Collection

The experts select microbial strains that can be potentially used against fungal and bacterial pests, and examine the factors underlying their favorable properties, such as the production of chitin and protein-degrading enzymes, as well as antimicrobial substances. The impact of various environmental factors – high temperature, salt and drought stress, pesticides – on the selected fungal and bacterial strains is being analyzed in detail, and the process of producing the strains selected for biological control is being optimized. The researchers are compiling fungal-bacterial mixtures suitable for the agricultural conditions and challenges of Hungary and Turkey, from which they are developing soil and foliar inoculant prototypes, developing the technology for open field application, and conducting seedling trials with them – the announcement says.

MTI