Fruit growing
and viticulture of South Russia
Phytosanitary condition of plants
The ability to effectively protect orchards against apple scab is threatened by Venturia inaequalis developing resistance to fungicides with a particular mode of action. Three pathogen populations from orchards in the Krasnodar region were used in dose-effect tests to examine the susceptibility of the apple scab pathogen population to cyprodinil. One of the populations was collected in an abandoned garden and was the baseline. The rest of the populations are collected in commercial gardens with the annual use of fungicides, including cyprodinil. The effect of 7 concentrations of cyprodinil was determined: 0.001, 0.01; 0.10; 0.50; 1.00; 10.00 and 50.00 mg/l for the growth of monospore pathogen isolates on Leroux synthetic medium. A total of 63 fungus isolates were analyzed. The growth of mycelium on the fungicide was expressed as a percentage relative to the control variant of the medium. The concentration of fungicide active ingredient that resulted in a two-fold inhibition of growth, called the effective 50 % concentration (EC50), was found using a probit regression transformation of the relative mycelial growth on the active ingredient. Analysis of dose-effect curves showed hormetic responses at low fungicide concentrations. The results of the study revealed that the sensitivity of the original population was significantly higher than that of the two fungicidal populations at a significance level of p
Due to the high harmfulness of aphids in fruit and berry complexes and the poor knowledge of their life activity in the North-West region of Russia for three years 2019-2020 monitoring of their species composition and population dynamics was carried out in the educational and experimental orchard of St. Petersburg State Agrarian University (SPbSAU) (Pushkinsky district of St. Petersburg). Insect trapping was carried out with a Malaise trap. Nineteen species have been marked and identified, of which 6 are direct pests of fruit and berry crops. Five species damage field crops; the life cycle of six species is associated mainly with non-fruit trees and shrubs of the region; the remaining two species feed on weedage. The largest number of species was noted in 2019 17; in 2020 and 2021 6. At the same time, 2021 is the leader in terms of the number of identified individuals, moreover, mass capture was associated with the species Euceraphis punctipennis Zett. Species quite rare in the region, the Oxton aphid Hyperomyzus picridis Börn. and large thistle aphid Uroleucon sonchi L. were noted. Regularities in the dynamics of the number of insects during the growing season were analyzed. The largest number of aphids in the trap in 20192020 recorded in August-September, the period of their remigration to the primary hosts. In 2021, the maximum number of insects was observed at the end of May, due to migration to secondary hosts. The impact of weather anomalies in 2021 on the vital activity of phytophages was assessed. The largest number of aphids was observed in May due to high air temperature with sufficient precipitation. A further increase in temperature in June with absence or low total precipitation, significantly reduced the number of insect populations. The Malaise trap proved to be quite effective when used for monitoring aphids; its advantages lie in the fact that the trap can be installed at any point of any agrocenoses, is not stationary and is convenient for material selection.
Monitoring phytosanitary studies have shown differences in the prevalence and harmfulness of the European grapevine moth on vine plantations in the Rostov region in 2021 and 2022. Under favorable conditions for the development of the pest, yield losses from its impact on the generative organs of grapes can reach 40%, and the damage caused by it can contribute to the development of mycoses. A significant increase in the first generation of male butterflies was noted in 2022 compared to 2021. In our opinion, the increase in the number of the pest was due to favorable conditions for the wintering forms of the European grapevine moth. In the autumn-winter period, the sum of negative temperatures was 2.4 times less than the long-term average norm. In 2021, the second generation of the pest was the most numerous, in 2022 the first, which can be explained by the influence of meteorological factors, especially air humidity. In particular, during all phases of the growing season in 2021, air humidity was above 60%. The most favorable year for the development of the third generation of the European grapevine moth was 2021, as evidenced by the largest number of pest males in pheromone traps. To reduce the harmfulness of the European grapevine moth, protective measures were taken against the second and third generations of the pest. For this purpose, the insectoacaricide Kinfos (active ingredient: dimethoate + beta cypermethrin 300 + 40 g/l) was used, the application rate was 0.4-0.5 l/ha. The use of the insecticide on the varieties Cabernet Sauvignon, Sibir'kovyy, Kristall, Tsvetochnyy contributed to a significant reduction in the prevalence of the pest, compared with untreated plantations. The listed varieties are characterized by the highest population of the pest. On the varieties Baklanovskiy, Denisovskiy, Kaberne severnyy, Kunlean', Pervenets Magaracha, Preobrazheniye revealed the least distribution of european grapevine moth.
Krasnodar region is the leading region of Russia in the production of grapes, one of the most important branches of production in the world. In the region, about 80% of the area is occupied by technical varieties. Fungal diseases, in particular leaf spots, cause significant damage to viticulture, as they can lead to a significant decrease in yield capacity. One of these diseases is necrotic leaf spot caused by fungi of the genus Alternaria Nees. The article provides an assessment of the incidence of hybrid forms of this disease. In the conditions of 2019, which was characterized by elevated average monthly temperatures during the growing season, the greatest spread of the disease was observed on hybrid forms of Tana 19 and Tana 92, on which the pathogen was present in a parasitic form. In the conditions of a later start of vegetation in 2020, the intensity of disease development was low on all varieties (0.7-12.3 %). In 2022, there was a shortage of precipitation in several months of the growing season, as a result of which the pathogen spread less on all hybrid forms and was present mainly as a saprotroph on weakened leaves. The spread and intensity of the disease development differed depending on the shoot tier the most severe leaf damage is noted on older leaves of the lower tier, the least on young, or leaves of the upper tier. Tana 92 was characterized by the greatest infestation of leaves of the middle and lower tier among all forms. When analyzing the mycopathocomplex of necrosis on the leaves of hybrid forms, it was found that it contains 8 species of hyphomycetes, of which 50 % are different species of Alternaria.
Plum pox virus in stone fruit crop plantings is one of the factors increasing the cost of cultivation of these crops. Infestation of stone fruit crops can reach 41-50 % in the Russian Federation regions of the middle zone, which is a serious threat to the production process. Infection with this virus often causes drop of leaves, ovaries and fruits in susceptible varieties. Methods to combat this virus are expensive and difficult to implement in the technological process. The most effective approach is plantation monitoring and elimination of infected plants. Since PPV contains RNA in its structure, the assay must obtain a quality preparation of total RNA. To obtain information on the quality of the isolated RNA, internal positive controls of RT-PCR are often used. In this work, the method for identification of the plum pox virus using a duplex with an internal amplification control was perfected. The ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit gene was used as a control because of its stable expression and high mRNA copy number. The material for this study was leaves of Kabardinskaya ranniaya plum (Prunus domestica L.), collected in early and late May in Krasnodar (Krasnodar region). The analysis was performed using molecular biological methods of reverse transcription and polymerase chain reaction. Detection of amplification products was performed in 2% agarose gel. Plum pox virus was diagnosed in all examined samples of symptomatic material. Multiplex PCR with the primer pairs under study required the use of gradient annealing of the primers with a temperature change of 3.18 C/sec. When using a cDNA matrix less than 50 ng/l, a decrease in PCR quality is possible. A method for the diagnosis of plum pox virus using an internal amplification control was perfected and modified.