Fruit growing
and viticulture of South Russia
With the climate change on the planet towards warming, the fungi of the genus Alternaria Nees became more active. Due to the prevailing climatic conditions, some species of this genus changed their status and acquired signs of facultative parasitism and complete parasitism on a number of cultivated plants, including the apple-tree. In vitro scientific studies are required to effectively control the disease, in the pathogenesis of which a large number of species are involved. At the same time, it is necessary to achieve fast and guaranteed growth of each of the fungus in the experiments. In this regard, the selection for fungi of the genus Alternaria, causative agents of apple fruits core rot, optimal for the cultivation of nutrient mediums is urgent. The studies were carried out by methods of laboratory and comparative analyzes. The growth of two strains of the causative agent of the apple fruit core rot of Alternaria alternata (Fr.) Keissl. on 12 nutrient mediums. Colony growth rate and morphological and cultural traits were assessed. As a result of research the strains of apple fruit core rot agent, a variation not only in the growth rate of colonies, but also in their cultural characteristics, depending on the compositions nutrient medium. A comparative study of the morphological and cultural characteristics of A. alternata strains FR20IV and FR20VI on various nutrient mediums made it possible to identify three universal mediums most suitable for their cultivation and identification, namely carrot, potato agars and Sabouraud's medium, according to the following criterions: ensuring the maximum degree of sporulation, rapid growth and development of the mycelium of the fungus, as well as easiness of preparation of revealed optimum cultural mediums.
This review was carried out on the topic of bacterial population of grapevine, with an emphasis on the functional structure of these communities. Bacterial communities in microbiota of grapevine are the most numerous. According to the localization on the plant, the non-pathogenic part of the microflora is divided into endophytic, which occupies the internal spaces of the grapevine, and epiphytic, which occupies the surface. Most bacterial endophytes do not have a noticeable effect on grape, or this effect has not been studied, but it is known that some of bacterial endophytes can have beneficial effects, for example, to stimulate plant growth or prevent harmful effects of phytopathogens. Epiphytic microflora provides the primary immune barrier in the formation of non-specific immunity in plants. Surface bacterial communities of grapes are vary significantly depending on the occupied ecological niches: roots, leaves, bark, flowers, berries, seeds. The article outlines the role of bacterial communities in ontogeny of grapes and opportunities for its practical use to increase in immune resistance of the grapes. In the literature, there are references to at least twelve genera of bacteria isolated from the microbiota of grapes and exhibiting the antagonistic properties to its pathogens. Species of the Bacillus genus are especially actively used in this area. The factors that form the quantitative and qualitative composition of bacterial microbiota were indicated: anthropogenic, naturalgeographical, edaphic, and genotypic (varietal). Anthropogenic factors have the greatest impact. The direct impact the microbiota in this case is expressed in the introduction of agrochemicals and pesticides, and indirectly associated with pruning, grafting, forming bushes, etc. It is known that the nature of the microbial community varies considerably in the vineyards with organic management.
One of the most important vegetable crops in Russia is cabbage, which includes a number of varieties, including cauliflower. The content of vitamin C, carbohydrates, proteins, acids and minerals in cabbage determines its value as a food product. Currently, one of the areas of research aimed at developing new effective, economical and environmentally friendly echnologies for storing vegetable juicy raw materials is the use of various types of physical treatment, including electromagnetic fields. This article presents the results of studying the influence of extremely low frequency electromagnetic fields the content of water, fiber, soluble carbohydrates (sugars and starch), protein and vitamin C in the cauliflower cultivar of Ardent during storage. The objects of research were treated with an electromagnetic field (25 Hz, 10mT, 30 min) in a laboratory experimental setup and were stored for three weeks at a temperature of 41 º and air relative humidity of 753 %. It was found that, in comparison with the control, the ELF EMF treatment of cauliflower leads to a slightly more active loss of water, and is also ccompanied by a decrease in the mass fraction of cellulose by an average of 5.3 % and an increase in the mass fraction of soluble carbohydrates by 18.1 %, protein by 4.6 % and vitamin C by 14.4 % during storage. The study of the regularities of the influence of the treatment of vegetable juicy raw materials with electromagnetic fields of extremely low frequencies on the biochemical composition can make it possible to develop new storage methods.
This paper presents the results of experimental studies of the temperature conditions influence during storage from +4 to +22 ºC on the commodity quality, organoleptic parameters and losses of fresh tomatoes of the Torbash variety. The assessment of commodity quality and quantitative losses was carried out by the expert method. As a result of the studies, carried out it was found that the best commodity quality of fresh tomatoes was preserved on the 2nd day of storage at temperatures from +4 to + 12 ºC, and on the 10th day of storage at temperatures from +6 to +12 ºC. The influence of storage temperature conditions the quantitative losses was studied: in the temperature conditions +4, +16-+22 ºC, the microbiological losses of tomatoes exceeded the losses ones due to natural loss. The maximum value for microbiological losses was recorded at storage mode of +18 ºC ‒ 9,4 %, the minimum value at +16 ºC (5,5 %). The greatest number of tomato`s losses from natural loss was observed at +14 ºC, the minimum at +22 ºC. Quality indicators such as shape, appearance, color, smell, freshness, taste and integrity of fruits were evaluated using a 10-point organoleptic scale. As a result of the studies, it was found that the organoleptic parameters in the temperature range from +4 to +16 ºC the tomatoes remained stable until the 6-8 day of the storage period, at high temperatures (+22, +20 ºC), the greatest change in the fruits organoleptic parameters was observed on the 10th day during storage.
The article presents the results of studying the quality indicators of wine alcohols, distillates and wine material from various grape raw materials to ground the possibility of developing a technology of high-quality wine spirits, including the processing of fresh grapes for wine materials without sulfitation and the use of enzyme preparations, and clarification of grape must by sedimentation, distillation of wine materials and rectification of the obtained distillates using the modes that allow to obtain wine alcohols with a strength of at least 94 % vol. It was found hat the yield of grape must of table grape varieties is low 70.8 dal out of 1033 tons of grapes. In an dry wine material from table varieties, the mass concentration of volatile acids exceeded the maximum permissible limit 1.60 g/dm3 . It is noted that during distillation of wine materials, the strength of distillate obtained is directly proportional to the volume fraction of ethyl alcohol of the original raw material and it was 31.9 % vol. (table grapes) and 39.5 % vol. (Crystal). Analysis of the volatile components of distillates and wine alcohols showed that the mass concentrations of the compounds analyzed in the wine alcohols are directly proportional to their content in the corresponding distillates; there is also a positive trend in reducing undesirable components in the rectificate produced. The selected rectification mode made it possible to reduce the amount of higher alcohols by 1.5 times for the Crystal variety and by 4.7 times for the table varieties. The content of esters in wine alcohols increased in 2-2.5 times mainly due to ethyl acetate, the boiling point of which is close to the boiling point of ethanol. It is shown that to obtain high-quality wine alcohols, it is advisable to use the substandard grapes both table varieties and technical varieties as raw materials.