Special aspects of plum clasterosporiosis development in Krasnodar Krai

В статье приведены результаты исследований развития клястероспориоза (возбудитель Stigmina carpophila (Lév.) M.B. Ellis, син. Clasterosporium carpophilum (Lév.) Aderh.) на сливе в Краснодарском крае в изменяющихся погодно-климатических условиях. В последнее десятилетие у возбудителя болезни выявлены изменения в биологии развития, что связано с участившимися экстремальными погодными условиями (количество температурных максимумов выше +30ºС, рост годового количества осадков - 100-300% нормы). Целью работы являлось выявление особенностей развития клястероспориоза сливы в Краснодарском крае в изменяющихся погодных условиях для оптимизации технологии защитных мероприятий. Исследования проводили в 2014-2019 гг. в центральной подзоне Прикубанской зоны Краснодарского края: ЗАО ОПХ «Центральное»; агробиологический стационар ФГБНУ «Северо-Кавказского федерального научного центра садоводства, виноградарства, виноделия» на сорте сливы Кабардинская ранняя. При выполнении работы использованы общепринятые и адаптированные методики. В результате изучения развития возбудителя клястероспориоза сливы впервые в крае был выявлен ряд параметров степени взаимосвязи развития патогена и погодных условий: более раннее заражение листьев - на 7-10 суток раньше; высокая первоначальная скорость развития болезни; сокращение продолжительности инкубационного периода на 2-3 суток. Выявлена оптимальная температура для роста мицелия гриба - +20…+24°С и температура, при которой происходит инфицирование +20…+26°С, при влажности воздуха 70-90 %. Определена температура, при которой отмечаются первые признаки болезни: при эпифитотии - +10-12°С, при умеренном распространении - +9-10°С. Результаты исследований позволят разработать практические подходы к усовершенствованию технологии защиты сливы от клястероспориоза. The article presents the results of studies of clasterosporiosis development (the infectious agent Stigmina carpophila (Lév.) M.B. Ellis, syn. Clasterosporium carpophilum (Lév.) Aderh.) on a plum in Krasnodar Krai in varied weather and climatic conditions. In the last decade, changes in the development biology were revealed in the pathogen of disease, which is associated with more frequent extreme weather conditions (the number of temperature peaks above +30 ºС, an increase in annual precipitation - 100-300% of the standard). The aim of work was to identify special aspects of plum clasterosporiosis development in Krasnodar Krai in changing weather conditions to optimize the technology of protective measures. The research was carried out in 2014-2019 in the central subzone of the Krasnodar Krai Kuban zone: ZAO experimental production farm "Tsentralnoye"; agrobiological station of the FSBSI North Caucasian Federal Scientific Center of Horticulture, Viticulture, Winemaking, on plum variety ‘Kabardinskaya Rannyaya’. Generally accepted and adapted techniques were used in the process of work. As a result of studying the development of plum clasterosporiosis infectant, a range of parameters of the degree of interrelation between the development of the pathogen and weather conditions was identified in the region for the first time: 7-10 days earlier infection of leaves; high initial rate of disease development; 2-3 days of incubation period reduction. The optimum temperature for the growth of the fungus mycelium was revealed - +20...+24°С, and the temperature at which the infection occurs - +20...+26°С, with an air humidity of 70-90%. We determined the temperature of first symptoms of disease - with epiphytotics - +10...+12°С, with moderate spread - + 9...+10°С. The research results will make it possible to develop practical approaches to improving the technology of protecting plums from clasterosporiosis.

А comprehensive assessment of the most promising varieties and forms of plum breeding in I. V. Michurin federal scientific center

The purpose of the research was a comprehensive assessment of plum varieties and forms and revealing the most promising for commercial use. Plantations laid in the city of Michurinsk, Tambov region. The assessment of plum plants for frost resistance was carried out in the middle of winter (II component). The artificial freezing of l year old shoots was made in January during 12 hours at -38 °C. The least subfreezing of the wood (2.8 and 2.9) was observed in elite form 22-29 and control variety “Etyud”, respectively. The moderate resistance of tissues (the degree of injury not over 3) was observed in “Vengerka Kursakova” variety and elite form 29- 136. The subfreezing level of vegetative buds in all studied varieties and elite forms did not exceed 2.5. The freezing at -38°C causes complete death of generative organs in all accessions. On the background of mass development of fungal diseases during the growing season 2016 because of high humidity and a deficit of positive temperatures and on the base of visual registration in field – the high resistant forms to Clasterosporium (“Vengerka Kursakova”) and to Monilia (22-29) were singled out. The intensity of fungal diseases in given accessions did not exceed 2 points. The highest productivity (7.43 t/ha) averagely during the years of investigations was found in “Vengerka Kursakova” variety and the data exceeded substantially the control one. The highest fruit weight occurred to be in “Radost” and “Artistichnaya” varieties with 40.3 and 40.8 g respectively and maximum values 51.7-52.3 g. The large-fruited group included the varieties “Etyud”, “Vengerka Kursakova” and elite form 29-136 where the maximum weight varied from 38.1 to 41.6 g. The varieties “Vengerka Kursakova”, “Dubravnaya”, “Artistichnaya” distinguished by sweet and sour fruit taste (tasting, assessment 4.4) and high commodity-consumer qualities of fruits. A promising plum variety “Vengerka Kursakova”, for use in industrial plantations of the Central Black Earth Region, was identified.

Comparative Evaluation of Eurytoma schreineri Schr. Attack Frequency on Transgenic and Two Conventional Plum Varieties

The plum seed wasp (Eurytoma schreineri Schr.) is a polyphagous pest that can cause significant damages to the plum crop. A transgenic plum variety, resistant to Plum pox virus, was evaluated to the attack frequency of E. schreineri in the context of reduced number of insecticide treatments against aphids, in comparison with two conventional plum varieties. The most affected variety by plum seed wasp, for two consecutive years, was ‘Stanley’, followed by ‘Reine Claude d’Althan’, and then ‘HoneySweet’ transgenic plum. The differences between variants were statistically assured.

The parameters of homemade jams after storage

Nowadays producing jams is considered a traditional way of plum processing in Hungary. Plum jams without added sugar can be stored This research aimed to analytically determine which quality parameters of the jams and to what extent they change during storage. Furthermore, this study intended to find out whether a concious consumer can presume any difference between varieties or the year of harvest, or wheather a one-time customer should suspect differences in quality parameters of the different products. This study focused on those differences or alterations in the parameters that occur in the jams made from several different plum varieties produced in different years. I analyzed the classic chemical parameters (dry matter content and ash content) and physiologically important nutritional components (phenolic and flavonoids antioxidants and vitamin C). In this research I used jams which were produced from 6 varieties grown in 2009 (President, Tophit, Bluefre, Elena, Presenta, Stanley), 4 varieties from 2010 (President, Bluefre, Elena, Presenta) and 6 varieties from 2011 (President, Tophit, Bluefre, Elena, Presenta, Stanley). Jams were produced with traditional technology in cauldrons without added sugar. Jars were placed into a relatively dark and cool place and were stored there until the analysis. Having regard to the results, when consumers choose between the different products they also choose quality since the processed plum variety, and the year of production/processing determine the nutritional value of the specific product. This could be used for market positioning and promotion of the product, however further research is needed to gain more information from the differences that derive from the varieties, year of harvest or other factors. This way fruit and jam producers could turn these informations into market advantage.