Apricot Orchards Research Articles

Apricot breeding for tolerance to Plum pox potyvirus in Nikita Botanical Gardens

For the fi rst time, the results of studying of varieties and breeding forms of apricot in the gene pool collection of the Nikita Botanical Garden – the National Scientifi c Center of the Russian Academy of Sciences (NBS – NSC) (Yalta, Crimea) on the tolerance to the plum Sharka disease – Plum pox potyvirus (PPV), are presented in the article. The collection includes varieties from diff erent ecological and geographical groups that give us the possibility to present an objective comparative assessment of their susceptibility to phytopathogens. Based on long-term monitoring of the apricot orchards on PPV susceptibility in the collection of NBG-NSC, single aff ected plants were discovered and exterminated. Molecular genetic approaches to apricot breeding for tolerance were demonstrated and PPV tolerant genotypes were selected. According to the results of the research, hybridization was carried out. During the entire period of the research, in order to create genotypes tolerant to PPV, 28 738 fl owers were pollinated and 2 908 hybrid seeds were obtained from which plants were grown. Under in situ and in vitro conditions, new breeding forms tolerant to PPV were obtained. The prospect of biotechnological methods usage for inducing the development of hybrid apricot embryos was shown. The conditions for their culture (trophic, hormonal, and physical) were determined, viable seedlings and plants were obtained in vitro and planted for further adaptation ex vitro and to the open ground. New created plants were evaluated and breeding forms were selected, characterized by tolerance to PPV, good fruit quality and high stable yield. Based on the comprehensive studies, two breeding forms of apricot (‘97 -11 ’and ’97-17’) tolerant to PPV and promising for breeding and commercial cultivation were identifi ed.

Improving soil health, weed management and nitrogen dynamics by Trifolium subterraneum cover cropping

The low organic matter and nitrogen levels in the soils, as well as the high weed pressure, typical of Mediterranean agroecosystems, necessitate a valid and sustainable alternative management. The utilization of cover crops such as Trifolium subterraneum L. may represent an innovative and efficient option for low-input and organic agricultural systems. In a 3-year experiment, we evaluated the effect of T. subterraneum and spontaneous flora cover cropping, with or without burying dead mulch into the soil, on the quali-quantitative composition of the weed seed bank in an apricot orchard. Moreover, the bacteria Nitrosomonas europaea and Azotobacter vinelandii, involved in the soil N cycle, and the content of ammoniacal and nitric soil nitrogen were quantified. For the first time, we demonstrated that T. subterraneum cover cropping with the incorporation of dead mulches into the soil on the one hand reduced weed biodiversity and the seed bank size (− 70% compared to conventional management following the standard commercial practices), while, on the other hand, increased the amount of N. europaea (+ 109%), A. vinelandii (+ 145%), NH4+ (+ 137%) and NO3− (+ 478%) in the soil. This approach was therefore found to be a major improvement in low-input agriculture and organic farming, and it can be applied in Mediterranean orchards as an eco-friendly strategy with the aim of reducing synthetic herbicides for weed control and mineral nitrogen fertilizers as the sole source of nitrogen supply.

Variations in water content of soil in apricot orchards in the western hilly regions of the Chinese Loess Plateau

AbstractLarge changes in land use and land cover types have been occurring in the hill and gully regions of the Loess Plateau since the end of the 1990s. This study revealed dynamic variations of soil water in different layers of representative land use and land cover types under different annual precipitation regimes and assessed the effects on soil water circulation in large areas of apricot [Armeniaca sibirica (L.) Lam.] trees, which have extensive and deep root systems. The results show distinct soil water deficit with a water content of generally <17% (60% of field capacity) in the deep layers of the soil profile of the apricot orchards. Several years after afforestation, perennial soil water deficit layers have subsequently developed around the root zone or even extended to deeper soil layers in the apricot orchards. In the soil profiles, increasing Cl contents are not related to increasing δ2H and δ18O values. This finding suggests that the extreme deficit of soil water and dry layer developments is mainly caused by intense transpiration, rather than by evaporation alone. The occurrence and development of soil water deficit layers in the deep soil profiles were the dominant factors that caused tree growth degradation and gradual death, due to lack of adequate stored soil water in the deep layers for use during a long arid time. Thus, the large‐scale establishment of arbor trees will likely lead to long‐term soil desiccation in the arid or semiarid regions on the Loess Plateau.

Soil microbial communities of Japanese apricot (Prunus mume) orchard under organic and conventional management

Organic farming has positive effects on soil microbial population, process, and activity. To examine effects of two different management methods (organic farming vs. conventional farming) on the cultivation of Japanese apricot, contents of fatty acid methyl ester (FAME), total glomalin, and soil chemical properties were analyzed and compared. The organic farming practice resulted in significantly higher contents of organic matter, total FAME, total bacteria, Gram-negative bacteria, arbuscular mycorrhizal fungi, and total glomalin than the conventional farming practice. Soil organic matter showed positive correlation with contents of soil microbial biomass, total bacteria, total glomalin, Gram-positive bacteria, Gram-negative bacteria, actinomycetes, and arbuscular mycorrhizal fungi. In 2018, the organic farming practice resulted in lower ratios of cy17:0 and 16:1ω7c than the conventional farming practice, indicating that microbial stress was reduced by the input of organic fertilizer into soil. Based on principal component analyses (PCA) of soil microbial communities, ratios of cy17:0 to 16:1ω7c in orchid soil can be used as microbial indicators to distinguish organically farmed orchard soil from conventionally farmed orchard soil.

First report of Candidatus Phytoplasma prunorum, the European stone fruit yellows phytoplasma on peach trees on the territory of Canton of Geneva, Switzerland

In recent years, ‘Ca. P. prunorum’, the agent of ESFY was reported from several apricot orchards of Canton of Wallis, the main apricot production region in Switzerland (Genini and Ramel, 2004). The psyllid vector Cacopsylla pruni was also found in several locations in the Lake Geneva area (Ackermann et al., 2006). The presence of the disease and of its proven vector C. pruni at the eastern part of the Lake Geneva area, as well as the existing risk of dissemination of ESFY to other stone fruit orchards along the Lake Geneva are the reasons for which ESFY needs to be studied further. ESFY and its possible dissemination through C. pruni on the territory of Canton of Geneva, bordering France, has never been yet studied. In 2016, visual observations were conducted in several stone fruit orchards near Geneva. Plant material was obtained from peach trees, displaying some of the typical symptoms such premature leaf colouration, leaf-roll, tree decline (Sabaté et al., 2015), in the autumn, when the concentration of the phytoplasma in the upper parts of the trees is the highest. Phloem was prepared from branches and was extracted with a CTAB-based adapted protocol (Lefort and Douglas, 1999). PCR amplification of phytoplasma DNA was achieved with the universal primers: fP1/rP7 (Deng and Hiruki, 1991; Schneider et al., 1995). All positive samples were tested with the ESFY-specific non-ribosomal primers ECA1/ECA2 (Jarausch et al., 1998). Typical symptoms of ESFY, like premature leaf colouration, leaf yellowing with reddish edges, leaf-roll, severe chlorosis, die-back of top branches and partial or, complete decline of the trees (Figure 1) were found in a peach orchard (GPS coordinates: 46°15'17.4"N 6°12'40.7"E) located in the area of Collonge-Bellerive, close to Geneva city. Ten trees were sampled in this orchard. The presence of ‘Ca. P. prunorum’ was confirmed in two of them (Figure 2 and Figure 3). At the beginning of spring 2017, the monitoring of the ESFY symptoms in the infested orchard was resumed. Early bud break was found on the two infected trees and the infection was confirmed again by PCR (Figure 4 and Figure 5). The same symptoms were observed in many trees of this orchard, which correlated with the previous autumn observations. Trapping confirmed the presence of the insect vector Cacopsylla pruni (Bodnár et al., 2018) in the infected area. In order to understand more about the origin and the diversity of ESFY phytoplasma in this area, additional plant and insect samples will be analyzed. The correlation between symptoms and infected plants will be studied further. We report here for the first time on the occurrence of ‘Candidatus Phytoplasma prunorum’ (‘Ca. P. prunorum’) the agent of ESFY on the territory of Canton of Geneva.

Epidemiological and molecular study on ‘Candidatus Phytoplasma prunorum’ in Austria and Hungary

AbstractThe epidemiology of ‘Candidatus Phytoplasma prunorum’ was studied in Austria and Hungary from 2014 to 2018. Testing of root samples showed average infections rates of 61 and 40% of the Austrian Prunus spinosa and Prunus domestica spp. insititia samples, respectively. In Hungary, on average 21% of the P. spinosa and 13% of the feral Prunus cerasifera samples were infected. The pathogen was found in 18 out of 19 apricot orchards and PCR positive Cacopsylla pruni were observed at 11 out of 17 sampling locations in both countries. In cage experiments with C. pruni remigrants successful pathogen transmission to Prunus armeniaca, P. domestica and P. spinosa seedlings in budding and foliated developmental stages was recorded, an inoculation access period of 4 hr was sufficient for transmission. A field experiment with ungrafted apricot seedlings planted in 2012 and 2014 indicated a prominent role of the insect vectors for disease spread. In 2017, 40 and 28% of the trees planted in 2012 and 2014, respectively, were infected. Molecular characterisation based on the genes aceF and imp allowed the discrimination between 10 phytoplasma types in apricots. Around 70% of the phytoplasma types in apricots were also common in P. spinosa, in P. domestica spp. insititia and in remigrant C. pruni pointing to a possible pathogen exchange by insects between wild and cultivated Prunus spp. For disease control, vector management over the entire flight period of the remigrants seems necessary; when selecting active compounds, the short inoculation access period of not more than 4 hr should be considered.

Contribution to the Energy Situation in Tajikistan by Using Residual Apricot Branches after Pruning as an Alternative Fuel

A lack of access to energy in the rural areas of Tajikistan is one of the current problems of the country. Tajikistan’s goal is to reach energy independency, and the main prospects for the country’s energy sector, which relies on energy imports during the long heating periods, are: higher exploitations of hydropower and development of other renewables, mainly biofuels. Tajikistan is a highly agrarian country, where agriculture is the dominant source of income for the majority of the population. Apricot belongs to the primary agricultural commodities; however, the cultivation and management of apricot orchards is associated with the annual accumulation of significant amounts of wood waste (residual branches after pruning), which represent a source of easily available biomass. Thus, the main focus of the present research was to investigate the properties (physical, chemical and mechanical) of densified briquettes and pellets from the residual apricot tree branches through the laboratory measurements by the standard methodologies and to calculate the energy yield and potential of this material for Tajikistan as a similar study has not been conducted yet. The results showed a good quality of apricot-based biofuels characterised by the high calorific value (NCV dry basis of 19.3 MJ kg−1), relatively low ash content (1.7%) and suitable values of the main chemical elements that fulfil the standard requirement on graded wooden biofuels. The total yearly energy yield of residual apricot branches was calculated to be 3245 TJ.

Yield prediction of apricot using a hybrid particle swarm optimization-imperialist competitive algorithm- support vector regression (PSO-ICA-SVR) method

Determining the important factors that affect the crop yield would be helpful for optimization of irrigation water usage, fertilizer applications, and other inputs and resources in farms. The main objective of this study was to evaluate the performance of a hybrid particle swarm optimization-imperialist competitive algorithm-support vector regression (PSO-ICA-SVR) method to predict apricot yield and to identify important factors affecting its yield in Abarkuh region, Yazd Province, Iran. One hundred ten apricot orchards were selected randomly and soil samples were taken at two layers (0–40 and 40–80 cm). Besides, water samples and leaves from branches without fruit were taken in each sampling point. Management information and apricot yields were achieved by completing a questionnaire. After performing yield modeling in MATLAB software, the results showed that the application of this hybrid algorithm identified 18 variables out of 61 studied variables as the most effective variables in apricot yield. The order of importance of selected variables in relation to the sensitivity analysis was irrigation intervals, spacing of rows planting, spacing of trees on each row, magnesium and nitrogen content of leaf, cultivar type, sand percentage and salinity of first studied layer, leaf sodium, soluble magnesium of first studied layer, sand percentage of second studied layer, age of trees, available potassium of first studied layer, silt percentage of second studied layer, coarse fragments percentage of first studied layer, soluble calcium, soluble magnesium and salinity of second studied layer. The validation results showed that the hybrid algorithm was able to estimate apricot yield with a relatively high accuracy (RMSE = 1.737 for training data and RMSE = 2.329 for testing data). Also, the use of efficiency index (EFI) showed that the hybrid algorithm has a high efficiency (about 99%) for prediction of apricot yield. As the apricot yield has a high sensitivity to the irrigation frequency, adopting management practices should be consider to increase water use efficiency in arid and semi-arid regions.

Role of Different Cover Crops on DTPA-Extractable Micronutrients in an Apricot Orchard

This study was conducted to compare the effect of different cover crop treatments on DTPA-extractable micronutrients (Fe, Mn, Zn, Cu) and soil pH in an apricot orchard with clay texture located in Malatya province of Turkey. For this purpose, 5 different experimental groups (Vicia villosa Roth (VV), Vicia pannonica Crantz (VP), Vicia pannonica Crantz and Tritikale mixture (70% + 30%, respectively) (VPT), Phacelia tanacetifolia Benth (PT), Fagopyrum esculentum Moench (FE)) and 3 control groups (mechanically cultivated (MC), herbicide treatment (HC) and bare control plot (BC)) were used in the apricot orchards. The soils were sampled from 0–20 cm and 20-40 cm depths in each plot for soil analyses. According to the obtained results, while cover crop treatments reduced pH values of soils according to the bare control, the cover crops increased the Fe, Mn and Zn contents of soils in the 0-20 cm soil depth. The highest Ext-Fe, Mn and Zn contents were obtained in the VV (14.83mg kg-1, 8.42 mg kg-1, 1.03 mg kg-1, respectively) at the 0-20 cm soil depth. As compared to bare control, highest percent increases in Fe, Mn and Zn contents were determined in the VV 27.73%, 31.69% and 37.54%, respectively. The greatest significant negative correlations in the VV treatment were observed between pH and Fe (-0.985**), between pH and Mn (-0.945**) and between pH and Zn (-0.764*). The greatest significant negative correlations in the VP treatment were observed between pH and Fe (-0.948**), between pH and Mn (-0.928**) and between pH and Zn (-0.722*). It was concluded based on current findings that cover crops, especially Vicia villosa Roth and Vicia pannonica Crantz could be incorporated into cropping systems to improve micronutrients and to provide a sustainable soil management.

RESPONSE OF HEAVY METAL CONTENTS IN APRICOTS TO DIFFERENT TRANSPORTATION MODES

In order to evaluate the effects of different transportation hubs on cultivated soil and apricots, macro and micro elements and heavy metal contents of fruit, leaf, kernel and soil samples collected from apricot orchards located at the border of the railroad, the motorway, the airport, and an orchard far from transportation modes were detected by ICP/OES (inductively coupled plasma / optical emission spectrometry). The results indicated the highest Cd, Pb and Ni contents of soil, fruit, and kernel samples under impacts of railroad transportation modes, whereas the highest contents of leaf were found under motorway side. All fruit samples contained higher amounts of Cd and Pb compared to permissible limits of FAO/WHO, and contents differentiated between sampling locations. There were no correlative relations found between transportation modes and macro-micro element contents. As a conclusion, in terms of heavy metal contamination, the orchards located at railway sides have the highest risk and this was followed by motorway side.

Determination of Sphaerolecanium prunastri Fonscolombe, 1834 (Hemiptera: Coccidae), and its parasitoids and predators in apricot areas of Malatya province, Turkey

This study, lasting 2 years, was carried out to determine the prevalence status, contamination level, parasitoids and predators of Sphaerolecanium prunastri in Malatya, the largest apricot-production area of Turkey. The contamination level and rate of S. prunastri were determined by a survey on trees selected by a systematic sampling method. Predators of S. prunastri were picked by a hitting method, and the parasitoids of the pest was gained by the use of culture cages. S. prunastri was seen at different rates in the province (few, medium, high) depending on the apricot orchard in the area, with an overall rate of about 23.5% prevalence in all apricot areas of Malatya province. Parasitoids of S. prunastri were determined as Cerapterocerus mirabilis (Hymenoptera: Encyrtidae), Pachyneuron muscarum (Hymenoptera: Pteromalidae), Coccophagus lycimna (Hymenoptera: Aphelinidae), Metaphycus silvestri (Hymenoptera: Encyrtidae) and Discodes coccophagus (Hymenoptera: Encyrtidae). Exochomus quadripustulatus (Coleoptera: Coccinellidae), Cybocephalus fodori (Coleoptera: Cybocephalidae) and Chrysopa sp. (Neuroptera: Chrysopidae) were observed as predators of S. prunastri.

Integrated life-cycle assessment in sustainable and conventional apricot orchards in southern Italy

Integrated life-cycle assessment in sustainable and conventional apricot orchards in southern Italy

Kayısı Bitkilerinden Elde Edilen Macrophomina phaseolina İzolatlarının Büyüme Oranları, Patojenisiteleri, Klorat Fenotipleri ve Genetik Çeşitlilikleri

Hatay iline bağlı kayısı alanlarında ve ev bahçelerinde 2014 yılı yaz aylarında arazi çalışmaları gerçekleştirilmiştir. Arazi çalışmaları sırasında sararma, solgunluk ve kök çürüklüğü gibi belirtiler gösteren kayısı bitkilerinden örnekler alınmıştır. Hastalıklı bitki dokuları yüzeyden dezenfekte edildikten sonra içinde tetrasiklin bulunan PDA ortamına ekilmiştir. Beş günlük inkübasyonun ardından, gelişen fungal koloniler mikroskobik ve makroskobik özelliklerine göre teşhis edilmiştir. Toplam 30 izolat Macrophomina phaseolina olarak teşhis edilmiştir. Tüm izolatlar tek mikrosklerot ya da hif ucu yöntemleri ile saflaştırılmış ve +6°C‘de saklanmıştır. Her bir izolattan 10mm çapında diskler alınarak PDA ortamına transfer edilmiş ve 15, 20, 25 ve 30, 35 ve 40°C sıcaklıklarda gelişmeye bırakılmıştır. Optimum gelişme sıcaklığı 25 ve 30°C olarak tespit edilmiştir. Klorat fenotiplerini belirlemek amacıyla tüm izolatlar 120mM potasyum klorat içeren minimal ortamlarda geliştirilmiş ve sonuçta 30 izolatın 21‘i sıkı, 6‘sı parçalı ve 3‘ü ise sınırlı gelişim göstermiştir. Lokasyon ile fenotip arasında herhangi bir ilişkiye rastlanmamıştır. Patojenisite testinde, tüm izolatlar kayısı, yerfıstığı, soya, mısır ve kavun bitkilerine inokule edilmiş ve 21 günlük inkübasyon süresinin ardından hastalık şiddeti 0-4 skalası kullanılarak belirlenmiştir. Hastalık şiddeti en yüksek 3,87 ile kayısı bitkilerinde oluşurken, yerfıstığı, soya, mısır ve kavun fidelerinde orta düzeyde hastalık şiddetinin oluştuğu ve aralarında istatistiksel olarak bir farkın olmadığı tespit edilmiştir. Moleküler çalışmalarda 14 farklı RAPD primeri kullanılmış olup, agaroz jel üzerinde oluşan 51 bandın 14‘ü polimorfik olarak bulunmuştur. Filogenetik ağaç üzerinde 2 temel grup gözlenirken, bu iki grupta pek çok alt grubun oluştuğu gözlenmiştir. Oluşan gruplar ile lokasyonlar, sıcaklık tepkileri, klorat fenotipleri ve patojenisiteleri arasında herhangi bir ilişkinin bulunmadığı tespit edilmiştir.

Use of Living, Mowed, and Soil-Incorporated Cover Crops for Weed Control in Apricot Orchards

Apricot fruits provide important health, economic, and nutritional benefits. Weeds damage apricot production directly and host the pests that cause damages to apricot trees. However, very few studies are available on weed control in apricot orchards. This research work was aimed at evaluating five cover crops for weed suppression in apricot orchard. The effect of living, mowed, and soil-incorporated cover corps on weeds was recorded and compared with glyphosate application and mechanical weed control. The cover crops were Vicia villosa Roth., Vicia pannonica Crantz, Triticale + V. pannonica, Phacelia tanacetifolia Benth., and Fagopyrum esculentum Moench. Five major weed species in the experimental area were Amaranthus retroflexus L., Convolvulus arvensis L., Tribulus terrestris L., Sisymbrium officinale (L.) Scop., and Sorghum halepense (L.) Per. The highest biomass production was noted for Triticale + V. pannonica in 2015 and for P. tanacetifolia in 2016. Living cover crops were effective in decreasing the weed biomass compared with the control. Both mowing and soil incorporation of cover crops were effective in decreasing weed richness and density over control. Mowed or soil-incorporated cover crops were more effective than herbicide or mechanical weed control, while F. esculentum was the least effective cover crop for suppressing weeds in apricot orchard. The results of our studies implied that cover crops could be used for weed control in apricot, and their mowing or soil incorporation could enhance their efficacy.

RELATIVELY SAFE TREATMENTS (PARTIAL / COMPLETE COVERAGE SPRAY) FOR THE CONTROL OF SCOLYTUS AMYGDALI (COLEOPTERA: SCOLYTIDAE) IN APRICOT ORCHARDS IN EGYPT

Anew relatively safe and commercial partial/complete coverage spray to control Scolytus amygdali (Coleoptera: Scolytidae) in the apricot orchard (applied only twice instead of 6 current MOA recommended chemical treatments/season) at El- Kattatba district, (Menofia Governorate). Percentages reduction of infestation for the following 7 applications for one-year treatment (2015), two successive years (2015 and 2016), and three successive years (2015, 2016 and 2017) were, respectively, as follow: A: Horticultural treatments: 1) dormant winter pruning (27.73 increased to 34.87 then 38.88%), 2) summer pruning (15.06 increased to 17.65 then 19.24%), 3) dormant and summer pruning (34.06 increased to 39.50 then 45.69%). B: Chemical treatment: 4) MOA recommended chemical treatments (3 treatments during spring and 3 treatments during autumn) (80.57 increased to 85.08 then 89.58%), 5) new commercial partial/complete coverage chemical treatments (1 treatment during spring and 1 treatment during autumn) (61.35 increased to 71.01 then 79.16%). Third: Horticultural (winter and summer pruning as an additive control) together with chemical treatments: 6) pruning together with MOA recommended treatments resulted in 86.03% increased to 88.24% then 96.39%, and 7) pruning together with new partial/complete coverage treatment resulted in 68.78% increased to 78.15% then 91.78%. The new commercial and relatively safe partial/complete coverage chemical control eliminates the pesticide use (2 treatments insteat of 6) and reduces residues, prevent the outbreaks of secondary species, decrease the environmental pollution, encourage the role of the biological control agents and obtain better production of decontamination of fruits through using limited insecticides.

Modeling seasonal variations of long-term soil CO2 emissions in an orchard plantation in a semiarid area, SE Turkey.

Emissions of soil CO2 under different management systems have a significant effect on the carbon balance in the atmosphere. Soil CO2 emissions were measured from an apricot orchard at two different locations: under the crown of trees (CO2-UC) and between tree rows (CO2-BR). For comparison, one other measurement was performed on bare soil (CO2-BS) located next to the orchard field. Analytical data were obtained weekly during 8years from April 2008 to December 2016. Various environmental parameters such as air temperature, soil temperature at different depths, soil moisture, rainfall, and relative humidity were used for modeling and estimating the long-term seasonal variations in soil CO2 emissions using two different methods: generalized linear model (GLM) and artificial neural network (ANN). Before modeling, data were randomly split into two parts, one for calibration and the second for validation, with a varying number of samples in each part. Performances of the models were compared and evaluated using means absolute of estimations (MAE), square root of mean of prediction (RMSEP), and coefficient of determination (R2) values. CO2-UC, CO2-BR, and CO2-BS values ranged from 11 to 3985, from 9 to 2365, and from 8 to 1722kgha-1week-1, respectively. Soil CO2 emissions were significantly correlated (p < 0.05) with some environmental variables. The results showed that GLM and ANN models provided similar accuracies in modeling and estimating soil CO2 emissions, as the number of samples in the validation data set increased. The ANN was more advantageous than GLM models by providing a better fit between actual observations and predictions and lower RMSEP and MAE values. The results suggested that the success of environmental variables for estimations of CO2 emissions using the two methods was moderate.

Severity of symptoms of European stone fruit yellows on different apricot varieties

Apricot is an important fruit crop in Hungary. There are large growing areas consisted of orchards of different sizes. These orchards are highly affected by a disease complex the so cold apoplexy with its characteristic symptoms. In this study, the effect of rootstocks and scion varieties on the severity of symptoms was investigated in an apricot orchard near Budapest. Symptoms were assessed in autumn at their most characteristic appearance on the combinations of 5 different scion varieties and 3 different rootstocks in 3 consecutive growing seasons. According to the results of the assessments in most cases, symptoms proved to be more frequent and stronger on trees grown on wild apricot rootstock than on plum intergrafted or myrobalan rootstocks. The variety Mandulakajszi proved to be consistently the least affected variety particularly on plum intergrafted rootstocks. Severity of symptoms observed on other investigated varieties deviated depending on the different rootstocks and growing seasons. To reduce the effect of growing seasons monitoring should be continued.&#x0D;

Review of the biology of plant psyllid (Cacopsylla pruni, Scopoli 1763), and its role in the spreading of European stone fruit yellows, ESFY-phytoplasma with Hungarian data

The European stone fruit yellows (ESFY) phytoplasma disease caused by pathogen ’Ca. Phytoplasma prunorum’ induces serious damages in cherry, sour cherry, peach, and apricot orchards mostly in Europe. Its known vector is the plum psyllid (Cacopsylla pruni). Many articles report on the biology (morphology, taxonomy, life cycle etc.) and the method of transmission of the pathogen by the vector, and the possibilities of their control. This paper reviews our knowledge about the vector, and summarises the results of an inland research carried out in a northeastern Hungarian apricot orchards. Our goal was to show some important data for the farmers or anyone who is interested in this disease and its vector. And give some known method that we can protect our orchards against them to prevent the appearance of the disease. As the psyllid that became infected with the pathogen can hold its infectionous capacity during their lifetime, it is very important to have enough knowledge about their lifecycle, that we can determine the right time and method to control them. We also have to know how to identify them; therefore, this paper lists several important data which can be helpful. The most important keys of identification are their wing color, which dark borwn in the apex and brown is in the remaining part of the forewing. The length of the antennae is also an important factor, since other genuse’s species have longer antennae than twice the width of the head. C. pruni has as long antennae as twice the width of the head. They return to Prunus species in early spring and we have to protect our orhards in this period against them. We have to use preparations with a knock down effect on them to prevent the inoculation of the pathogen into the trees in our orchards.

Characterisation of Pseudomonas syringae isolates from apricot orchards in north-eastern Italy

A set of 31 isolates were obtained from apricot (Prunus armeniaca L.) orchards showing symptoms of blast and gummosis in orchards located in north-eastern Italy, mostly during three subsequent growing seasons (2014–2016). These isolates were identified by means of their colony morphology, pathogenicity (hypersensitive reaction in tobacco leaves and the detection of both syringomycin and coronatine coding genes), genetic features (BLASTn analysis of the rpoD gene) and physiological tests (GATTa) as Pseudomonas syringae pv. syringae and P. syringae pv. morsprunorum race 1 and race 2 strains, respectively. Phylogenetic analysis based on the rpoD gene sequence showed that the two pathovars and two races are well separated and highlighted high intrapathovar/race variation for both P. syringae pv. syringae and P. syringae pv. morsprunorum race 2. Pseudomonas syringae pv. morsprunorum race 1 formed a unique clade that had high sequence homology. Repetitive element-based polymerase chain reaction fingerprinting analysis using the ERIC, REP and BOX primers again showed both high intra-pathovar variation within the P. syringae pv. syringae isolates, which grouped into six distinct clusters, and notable intra-race genetic diversity within both P. syringae pv. morsprunorum races. All 31 strains showed tolerance to copper at 200 ppm in vitro. Among these isolates, 13 were highly resistant (up to 500 ppm) and revealed the presence of the cusCBA gene cluster. All P. syringae pv. syringae strains showed ice nucleation activity, and nine were markedly active (up −3 °C) and characterised by the presence of the INAz gene. Finally, this study is the first report of the isolation of P. syringae pv. morsprunorum race 2 strains from apricot in Italy.

Потенциальные возможности использования временных серий индекса NDVI по данным MODIS для оперативного мониторинга абрикосового сада

Потенциальные возможности использования временных серий индекса NDVI по данным MODIS для оперативного мониторинга абрикосового сада