Fruit growing
and viticulture of South Russia
Phytosanitary condition of plants
This article presents an analytical review of modern world literature sources related to elements of technology for protecting the sapling in nursery farming from diseases and vermins. The data in presented presents on the state of nursery in the Russian Federation and abroad at present, the main problems of nursery development are shown. Analysis of literary sources of 2018-19 confirms the data obtained in previous years shown that in order to grow healthy, quality planting material, it is necessary to observe the complex methods: agrotechnical, biological, phytosanitarian and chemical, which include several stages. The first stage is to determine the state of the soil, the article shows how to clean the soil from pesticides and pathogen residues, to increase in soil microflora, to reduce soil degradation. The second stage is to select the source material, which should be healthy, varietal and adapted to local environmental conditions. The third stage is the study, classification and phytosanitary monitoring of vermins and diseases of sapling. The main diseases of saplings in the nursery are root cancer (Agrobacterium tumefaciens) and root rot (Phytophtora cactorum). The main vermins are various types of grub, aphids, ticks, goldfish, leafworms, mice and hares. Phytosanitary monitoring is carried out by a manual or modern automated method, using aerial photographs and drones. The fourth stage measures to control vermins and diseases: the use of microbiological and chemical pesticides; trapping and disorientation of pests using pheromones; restrain of vermins number by entomophages; weed control using special techniques for weeding row spacing.
One of the main problems of the fruit and berry industry currently is a group of systemic pathogens for which there are no effective remedies of protection. Viruses, viroids, phytoplasmas and bacterial pathogens cause huge damage to fruit producers. Their presence in plants reduces the yield and quality of agricultural crops. The prevalence of viral diseases in Russia varies from 32 to 80 % depending on the culture and region of cultivation. However, replacing the infected plant material with a nonviral one can increase productivity by up to 30%. For the production of virus-free planting material in the world, various methods for the elimination of viruses are used, including such as the culture of meristem (in vitro), thermotherapy, chemotherapy, micro grafting (microtransplantation) and cryotherapy of the meristem tips. These methods and approaches for the elimination of viruses are successfully used in various countries to effective viruses fight for almost all of the most economical important crops, which is an agricultural strategy for the production of virus-free plant material. The main factors affecting the efficiency of viruses elimination from plant material are as follows: type of virus, type of plant and its genotype, temperature and duration of thermotherapy, incremental temperature increase and its change, type and concentration of antiviral agents, explant source, tip size and the location of the meristem, genetic stability of the plant. The analyzed literature data on the elimination of viruses from plant material of various fruit crops show that the combination of methods for eliminating viruses has much higher efficiency when combining not only one, but several methods of plant healthing in turn, depending on the type of virus, type and variety of the crops.
In recent years, there has been an increasing of the economical importance of diseases of the vascular system of grapes all over the world. The main pathogens are specialized fungal pathogens, the so-called ESCA complex. These fungi cause various types of necrosis. The affected plants have a growth delay, shortening of internodes, intercellular chlorosis, and a reduction of the growth of the young shoots. Disease outbreaks are usually finished with the death of the vine after a few years. The severest form of the disease is apoplexy, which leads to the death of plants in just a few days. The consequences of the disease are the grape plantations productivity dropping. Fully disease-resistant cultivated or wild vine taxa do not currently exist. Biotechnology is the main global trend of the modern grapes protection (in the nurseries and exploited plantations), as well as in all fields of the plant growing. A sufficient number of scientific Publications have been devoted to the development of adaptive-integrated protection systems based on using of maximum possible non-chemical means of limiting or controlling t rachemicosis infection. In the world`s scientists` researches several solutions have been proposed: physical and biological ways to fight pathogens, and increasing in the resistance of plants themselves. The producers based on various Trichoderma strains among the biological methods that are widely used. They are used at all stages of reproduction in the nursery: soaking cuttings, fusion of the scion and rootstock, rooting. Studies of other authors have shown the ability of combinations of different strains of Pythium oligandrum to colonize the grapes roots and induce the protective reactions of the plant. Endophytic bacteria are also promising producers that suppress the development of the disease. All of these producers represent the opportunity to solve the problem of infection with tracheomycosis in nurseries and vineyards.
The study and generalization of world experience in research on the development of technologies to reduce losses, stabilize the quality and maximize the preservation of biologically active substances of crop products during storage, made it possible to conclude that research on the methodology for the application of electromagnetic fields of extremely low frequencies (EMF ELF) is relevant. to control the development of pathogenic microflora, leading to the development of diseases and, as a consequence, the loss of crop production. During the study, the composition of the microflora of strawberries was studied, it was found that the amount of mesophilic aerobic and optionally anaerobic microorganisms (MAaOAM) on the berries of the strawberry variety Marmalade, the harvest of 2019, ranged from 5000 CFU/g to 12000 CFU/g. MAaOAM are mainly represented by spore microorganisms, enterobacteria and yeast. The number of molds is from 110 CFU/g to 1400 CFU/g. The influence of EMF treatment by electromagnetic fields on the pathogens of strawberry fungal nature was investigated. In the samples treated with EMF ELF, in comparison with the control sample, the number of microorganisms after 14 days of storage was lower. The regularities of the influence of the EMF ELF processing parameters on the development of pathogenic microorganisms of strawberries in experiments and in vivo were revealed. It was established that the processing of strawberries of the variety Marmelada using ELF EMF with parameters: frequency 30 Hz, current strength 10. A, processing time 30 minutes has the maximum inhibitory effect on the development of phytopathogenic microorganisms Botrytis cinerea and Rhizopus nigricans.
The problem of storing fruits and vegetables and preserving their sensory and nutritional qualities is actual nowadays. It is extremely important to find such a technology for preserving fresh fruits and vegetables and with the use of which all the components of their chemical composition remain at a high level for the longest time in terms of their content and do not undergo significant changes, biological activity and safety. To ensure stabilization of commercial quality, maximum preservation of biologically active substances and reduction of losses during storage of berry raw materials, various technologies are used such as controlled gas environment, treatment with chemical reagents, microbiological preparations, the use of various physical factors. A comparative analysis of the growth dynamics of the populations of the fungal pathogens Botrytis cinerea and Rhizopus stolonifer was carried out depending on the parameters of their treatment with ELF EMF. The regularities of the influence of the ELF EMF processing parameters on the development of pathogenic microorganisms of strawberries in experiments and in vitro were revealed. It was established that in the experimental sample Botrytis cinerea treated with ELF EMF with parameters of 30 Hz, 10 A, 30 minutes, the number of colonies grown after 7 days was 1.8 × 102 CFU, which is 27.5% lower compared to the references. In the experimental sample of Rhizopus stolonifer treated with ELF EMF with parameters of 30 Hz, 10 A, 30 minutes, the number of colonies grown after 7 days was 2 × 102 CFU, which is 26.2% lower compared to the references. An analysis of the data obtained in vitro experiments allows us to conclude that the variant of processing ELF EMF with parameters of 30 Hz, 10 A, 30 minutes most effectively affects the inhibition of the growth rate of the fungal pathogens Botrytis cinerea and Rhizopus stolonifer, which cause diseases of strawberry berries.