Cherry blossom crown gall has caused serious damage to plant growth, and is highly contagious and extremely difficult to control. The antagonism of pathogens by rhizosphere bacteria has attracted widespread attention. However, there is still limited research on the cherry blossom crown gall. In this study, we explored the control effect of rhizosphere bacteria Pseudomonas aurantiaca ST-TJ4 on cherry blossom crown gall. We also investigated the long-term survival status of ST-TJ4 in the cherry blossom roots and the induction of plant defense resistance. The results showed that ST-TJ4 had obvious inhibition effect on the population of Agrobacterium tumefaciens, which could reduce the number of A. tumefaciens by 70% to 90%, and its population kept the advantage in the rhizosphere soil and cherry blossom roots. The incidence of crown gall in the therapy group and the prevention group was reduced by 37.5% and 50%, respectively, and the disease index was reduced from 80 to 20 and 10, respectively. At the 150th day, ST-TJ4 could still be isolated from the rhizosphere soil and root surface, indicating that ST-TJ4 could survive in soil for a long time and had long-term performance. Compared with the control group, the therapy group and prevention group could reduce the levels of H2O2, malondialdehyde (MDA) and the oxidative damage, and up-regulated the expression of active oxygen-related genes DHAR1, SOD1, GR1 and CAT to activate defense response. On the other hand, it could up-regulate the expression of SA1, SA2 and JA1 genes related to the induction of salicylic acid (SA) and jasmonic acid (JA), and lead to the increase of SA hormone level. Collectively, P. aurantiaca ST-TJ4 had the potential to be applied for biocontrol of cherry blossom crown gall by reducing root pathogen colonization and inducing plant resistance.

Fusarium crown rot (FCR) is a significant global issue in wheat production. Planting resistant cultivars is the most effective strategy for mitigating FCR damage. However, breeding for FCR resistance is challenged by the lack of a reliable and high-throughput method for rapid and accurate assessment of numerous genotypes. This study evaluated FCR resistance in 50 wheat genotypes using the common soil-based method. None of the genotypes were immune or highly resistant and only 6.0% (three genotypes) showed moderate resistance at the seedling stage. Resistant and susceptible genotypes were then selected for preliminary experiments. A rapid water-culture method for assessing FCR resistance in wheat seedlings was developed. Seedlings were planted in petri dishes and inoculated by spraying conidial suspensions. This new method, which takes 15 days (about 50% of the time required for soil-based methods), requires minimal space and eliminates variability associated with soil or potting mixes. The disease index correlation between water-culture and soil-based methods was significant (p < 0.01) with a correlation coefficient of 0.901. The resistance evaluation consistency among 50 genotypes using both methods was 94.0%, indicating high reproducibility and strong agreement with soil-based results. Therefore, this new method should be a valuable tool for initial screening of FCR-resistant germplasms from numerous genotypes in breeding programs.

Relevance. Engineering-geological surveys are an integral part of mining operations for various purposes. The quality of soil core sampling has an important impact on the results of engineering geological surveys. At the same time, obtaining a frozen rock core is complicated by an increase in the bottomhole zone temperature, which arises as a result of drilling. As the temperature rises, the physical and mechanical properties of frozen soils change, which leads to a transformation of the mechanism of their destruction and an increase in the likelihood of drilling emergencies. A core obtained under conditions of rising temperature does not allow for a reliably accurate assessment of the properties and structure of soils in their natural conditions. Therefore, there is a need to develop technological and technical means that help maintain the temperature regime of a rock mass under mechanical effect on it. The analysis of the conditions of core drilling in frozen rocks showed that, along with technological reasons, the design of the rock-cutting tool affects the increase in bottom-hole temperature. The article reveals the dependence of the temperature change at well bottom when drilling on the design features of the core rock-cutting tool. Aim. To study the impact of the design features of a drilling core tool on the nature of destruction of frozen soils, represented by loose sedimentary rocks as the most susceptible to changes in physical and mechanical properties with increasing temperature. The study was based on frozen soils that make up the of Yakutia, a large industrial region that requires frequent geotechnical surveys for its development. Objects. Core drilling tool design, mechanism of frozen rocks destruction, conditions for core sampling in frozen soils. Methods. Analytical method, experimental method, production test method. Results. The authors have determined the main directions for the development of core tools for high-quality core sampling in frozen soils. They derived the dependence of the magnitude of the temperature increase at well bottom on the orientation and size of the cutters reinforcing the rock-cutting tool.

Since 2002, ash dieback caused by the invasive fungus Hymenoscyphus fraxineus has been observed in Germany. The pathogen and its associated symptoms have fatal consequences for the vitality and survival of European ash (Fraxinus excelsior L.), an economically and ecologically important tree species. This study analyses the ash monitoring results of eleven intensive monitoring plots of the FraxForFuture research network distributed across Germany and focuses on within-stand differences of symptoms in dependence of small-scale site and tree properties. A cohort of 1365 ash trees was surveyed six times over three years, testing and applying a summer and a winter version of a nationally standardised ash dieback assessment key. The main disease symptoms (crown dieback and basal lesions) were more pronounced in areas with higher ash density, in edaphically moist areas (hydromorphic soils), on younger/smaller ash trees, and generally increased over time. However, the trend over time differed between single plots. In case of considering only the surviving part of the ash populations, crown condition even improved in 6/11 plots, indicating a selection process. Large basal lesions at the beginning of the observation period were a very good predictor for deadfall probability, especially on trees with lower stem diameter. Generally, ash dieback related symptoms at stem and crown were highly correlated. Silvicultural management practice in the past that actively pushed ash towards the moister end of its water demand spectrum has to be questioned in the light of ash dieback. Cost-intensive ash re-cultivation in the future-possibly with less dieback-susceptible progenies-should avoid pure ash stands and hydromorphic soil conditions.

Soilborne fungal pathogens that cause root rot, wilting and dying are the most important problems in pistachio production. The purpose of this study was to examine, isolate, and diagnose the pathogens from diseased pistachio trees in orchards and nurseries located in southeastern Turkey. Fungi isolated from the pistachio trees were identified by morphology and the sequences of the internal transcribed spacer (ITS) region and translation elongation factor-1 alpha (TEF-1 alpha). Fusarium solani, Fusarium oxysporum, Fusarium brachygibbosum, Fusarium chlamydosporum and Macrophomina phaseolina were the most important fungi causing root rot, wilting and decline of pistachio trees. Pathogenicity studies showed that all of the fungi identified can colonize and damage the vascular tissues of a sapling and cause substantial lesions and vascular discolourations. This study provides the first evidence of wilting due to the root and crown rot in pistachio trees in Siirt province of Turkey caused by some Fusarium species, especially F. solani, F. oxysporum, F. chlamydosporum, F. brachygibbosum and M. phaseolina. Finally, the research enabled the identification of some fungal pathogens that are seriously harming pistachio trees in southeastern Turkey.

Knowledge of the health condition of urban trees is fundamental for making decisions regarding management and resource allocation. The objective of this study was to determine the current health status of the trees at the National Institute of Astrophysics, Optics, and Electronics (INAOE) in San Andres Cholula, Mexico. Five health indicators previously used in urban forests were assessed. The structure and diversity indicator indicated the existence of 2210 trees, mostly (58.8 %) of small size ( 40 %) in some of its species and low percentages of dieback. Live crown ratio and crown density were moderate in eight and six species, respectively. The tree damage indicator showed the existence of 44 damaging agents in 956 trees (43.3 % of the total), highlighting the ball moss ( Tillandsia recurvata ), the felt fungus of evergreen ash ( Septobasidium sp.) associated with an armored scale, the same fungus also affecting white cedar ( Hesperocyparis lusitanica ) in association with another scale (a new record), and two bark beetles, Hylesinus aztecus in evergreen ash, and Phloesinus sp. in white cedar. Regarding the mortality indicator, 75 trees (3.3 %) were recorded. Finally, the soil condition indicated that the pH was close to neutral, with electrical conductivity values above 2 dS m(-1) and a low beneficial mycoflora population. All these factors, together with the imbalance in tree diversity, high planting density, compacted soils, and the presence of risky trees, are negatively affecting the health of INAOE's tree community.

The record-breaking drought in 2018 caused premature leaf discoloration and shedding (early browning) in many beech (Fagus sylvatica L.) dominated forests in Central Europe. However, a high degree of variability in drought response among individual beech trees was observed. While some trees were severely impacted by the prolonged water deficits and high temperatures, others remained vital with no or only minor signs of crown vitality loss. Why some beech trees were more susceptible to drought-induced crown damage than others and whether growth recovery is possible are poorly understood. Here, we aimed to identify growth characteristics associated with the variability in drought response between individual beech trees based on a sample of 470 trees in northern Switzerland. By combining tree growth measurements and crown condition assessments, we also investigated the possible link between crown dieback and growth recovery after drought. Beech trees with early browning exhibited an overall lower growth vigor before the 2018 drought than co-occurring vital beech trees. This lower vigor is mainly indicated by lower overall growth rates, stronger growth declines in the past decades, and higher growth-climate sensitivity. Particularly, warm previous year summer conditions negatively affected current growth of the early-browning trees. These findings suggest that the affected trees had less access to critical resources and were physiologically limited in their growth predisposing them to early browning. Following the 2018 drought, observed growth recovery potential corresponded to the amount of crown dieback and the local climatic water balance. Overall, our findings emphasize that beech-dominated forests in Central Europe are under increasing pressure from severe droughts, ultimately reducing the competitive ability of this species, especially on lowland sites with shallow soils and low water holding capacity.

The growth peculiarities of Scots pine ( Pinus sylvestris L.) have been studied by the example of an even-aged pine stand of high density. A long-term research has been conducted on a permanent sample plot. The data has been collected from the stand aged from 37 to 55 years. The characteristics of individual trees and the entire stand during the growth period in the absence of external influences (cutting, windfalls, pest damage, etc.) and after improvement cuttings have been analyzed. The influence of the amount of resource available to a tree on the formation of crowns, root systems and stem wood has been investigated. The size of the available resource has been the square of the dominance area. The root system of the pine trees of the studied stands is compact in size and, despite the high stand density, due to the high content of nutrients in the soil and the absence of moisture deficiency, it sufficiently ensures intensive tree growth corresponding to the conditions of the I quality class. It has been found that under these conditions, the average area of the root system is proportional to the average square of the dominance area. It has been shown that the stem diameter at a height of 1.3 m in the absence of external influences significantly depends on the square of the dominance area. The correlation coefficient of these indicators for the studied stand at the age of 37 is 0.89. The influence of cuttings on annual radial increment has been studied using dendrochronology methods. It has been revealed that in the year following the cutting, it has increased by 1.3-2.0 times, depending on the increase in the square of the dominance area. A method has been proposed for calculating the competition coefficient as a share of the resource required for the free growth of a tree, which is redistributed between its closest neighbours. Long-term observations have shown that with competition coefficients exceeding 0.6-0.7, the stem diameter increment rate decreases significantly, and the trees develop a sparse crown extending less than 40 % of the tree height. This, in turn, leads to growth retardation and a transition to a depressed state. This, in turn, leads to growth retardation and a transition to a depressed state.