Healthy Trees Research Articles

Can canopy temperature acquired from an airborne level be a tree health indicator in an urban environment?

Nowadays, gathering information about tree health conditions in cities is necessary. Trees are essential in regulating urban microclimate and mitigating the urban heat island effect. Therefore, their health status should be crucial in urban vegetation monitoring. The growing number of new cameras, sensors and research methods allows for a broader application of thermal data in remote sensing vegetation studies. This research aimed to evaluate whether it is possible to use thermal infrared data to assess the health condition of selected species of deciduous trees in an urban environment. More specifically, the data must have a 3.6–4.9 µm spectral range, obtained during the day and the night. For this purpose, research was carried out in the city center of Warsaw (Poland) in 2020. During the airborne data acquisition, thermal data, laser scanning and RGB images were collected. Synchronously with airborne data, 617 ground references were obtained in different health condition classes (healthy, slightly poor condition, poor condition and dying) for five tree species: Acer platanoides, Acer pseudoplatanus, Aesculus hippocastanum, Tilia cordata and Tilia × euchlora. The results were as follows: (i) healthy trees were cooler than trees in poor condition and dying both during the daytime and nighttime; (ii) the difference in the canopy temperatures between healthy and dying trees was 1.06 °C of mean value on the nighttime data and 3.28 °C of mean value on the daytime data; (iii) all condition classes significantly differ from each other on daytime thermal data. The aerial thermal data can be considered a new alternative to hyperspectral data. Thermal sensing represents another method of assessing the health condition of trees in an urban environment – especially data obtained during the day, which can differentiate condition classes better than data obtained at night. The method based on thermal infrared and laser scanning data fusion could be a quick and efficient solution for identifying trees in poor health.

Exploring the diversity and host association of tarsonemid mites in West Bengal, a highly biodiverse state of Eastern India

The family Tarsonemidae is an extremely diverse assemblage of heterostigmatid mites which include phytophagous, fungivorous, detriphagous, algivorous and insect parasitic species living in various terrestrial, arboreal, subcortical or nidicolous habitats. Many of these mites pose a serious threat to global agriculture due to their direct feeding on crop plants or indirect transmission of disease-causing bacterial or fungal spores to healthy plants. For instance, Polyphagotarsonemus latus may reproduce year-round in all tropical and subtropical habitats and feed on more than 60 different plant families. Steneotarsonemus species, such as S. spinki and S. subfurcatus, attack rice and can significantly reduce the harvest, S. ananas attacks pineapple, and S. laticeps targets lilies. In temperate forests of the Northern Hemisphere, several Tarsonemus species phoretic on curculionid beetles transfer lethal fungal spores on healthy pine trees, while some other species pose a real hazard to cultivated mushrooms and stored products.

Dynamic changes of gut bacterial communities present in larvae of Anoplophora glabripennies collected at different developmental stages.

The Asian long-horned beetle, Anoplophoraglabripennies (Motschulsky), is a destructive wood-boring pest that is capable of killing healthy trees. Gut bacteria in the larvae of the wood-boring pest is essential for the fitness of hosts. However, little is known about the structure of the intestinal microbiome of A. glabripennies during larval development. Here, we used Illumina MiSeq high-throughput sequencing technology to analyze the larval intestinal bacterial communities of A. glabripennies at the stages of newly hatched larvae, 1st instar larvae and 4th instar larvae. Significant differences were found in larval gut microbial community structure at different larvae developmental stages. Different dominant genus was detected during larval development. Acinetobacter were dominant in the newly hatched larvae, Enterobacter and Raoultella in the 1st instar larvae, and Enterococcus and Gibbsiella in the 4th instar larvae. The microbial richness in the newly hatched larvae was higher than those in the 1st and 4th instar larvae. Many important functions of the intestinal microbiome were predicted, for example, fermentation and chemoheterotrophy functions that may play an important role in insect growth and development was detected in the bacteria at all tested stages. However, some specific functions are found to be associated with different development stages. Our study provides a theoretical basis for investigating the function of the intestinal symbiosis bacteria of A. glabripennies.

The Changes of Microbial Communities and Key Metabolites after Early Bursaphelenchus xylophilus Invasion of Pinus massoniana.

Pine wood nematode, Bursaphelenchus xylophilus, is a worldwide pest of pine trees, spreading at an alarming rate and with great ecological adaptability. In the process of causing disease, the nematode causes metabolic disorders and changes in the endophytic microbial community of the pine tree. However, the changes at the pine nidus during early nematode invasion have not been well studied, especially the differential metabolites, in Pinus massoniana, the main host of B. xylophilus in China. In this study, we analyzed the endophytic bacterial and fungal communities associated with healthy and B. xylophilus-caused wilted pine trees. The results show that 1333 bacterial OTUs and 502 fungal OTUs were annotated from P. massoniana stem samples. The abundance of bacterial communities in pine trees varies more following infection by B. xylophilus, but the abundance changes of fungal communities are less visible. There were significant differences in endophytic microbial diversity between wilted and healthy P. massoniana. In wilted pine trees, Actinobacteria and Bacteroidia were differential indicators of bacterial communities, whereas, in healthy pine trees, Rhizobiales in the Proteobacteria phylum were the major markers of bacterial communities. Meanwhile, the differential markers of fungal communities in healthy pines are Malasseziales, Tremellales, Sordariales, and Fusarium, whereas Pleosporaceae is the key marker of fungal communities in wilted pines. Our study examines the effect of changes in the endophytic microbial community on the health of pine trees that may be caused by B. xylophilus infection. In parallel, a non-targeted metabolomic study based on liquid mass spectrometry (LC-MS) technology was conducted on pine trees inoculated with pine nematodes and healthy pine trees with a view to identifying key compounds affecting early pine lesions. Ultimately, 307 distinctly different metabolites were identified. Among them, the riboflavin metabolic pathway in pine trees may play a key role in the early pathogenesis of pine wood nematode disease.

Changes in Microbial Community Structure in Response to Gummosis in Peach Tree Bark.

Peach gummosis disease has been identified as a serious challenge in Korean agriculture and has developed to become a major cause of agricultural productivity losses. However, treatments for gummosis have not been systemically established and studies of the microbiome closely related to this plant disease are lacking. Therefore, we analyzed the bacterial and fungal communities in the bark and rhizosphere soil of healthy peach trees and those with gummosis. Through high-throughput sequencing, we obtained unprecedented insights into the bacterial and fungal dynamics of each group, including their diversity and taxonomic classification, as well as network analyses. We found that the presence of gummosis drives a significantly higher alpha diversity in the bark bacterial community. Peach gummosis bark mycobiomes included greater numbers of opportunistic pathogens such as Ascochyta, Botryosphaeria, Saccharomyces, Nectriaceae_NA, Trametes, and Valsaceae_NA. However, the microbiome also included bacteria beneficial to plant growth and the production of polysaccharides-namely, 1174-901-12, Catenibacterium, Cutibacterium, Friedmanniella, Methylobacterium-Methylorubrum, Pseudomonas, Rhodobacter, and Sphingomonas. Furthermore, we confirmed that gummosis induced a more complex structure in the bark microbiome network. We conclude that the findings of this study provide a valuable aid in profiling the overall peach tree microbial ecosystem, which can be utilized to develop precise biomarkers for the early diagnosis of gummosis.

First Report of Armillaria root disease of Celtis laevigata caused by A. gallica in South Carolina, USA.

Celtis laevigata (sugarberry, southern hackberry) is an important, shade-tolerant, deciduous hardwood tree species that occurs naturally in flood plains, along streams and rivers, and in urban landscapes of the southeastern USA (Kennedy 1990). In recent years, dieback and mortality of C. laevigata have been commonly observed in some areas of South Carolina (SC) and Georgia (GA) (Poole et al. 2021). In April/May of 2018, the crown conditions and root systems were examined for three C. laevigata trees in North Augusta, SC. The crown of each tree was visually assessed using the method of Poole et al. (2021). Root samples were obtained by excavating two main roots ca. 2 meters away from the stem of each tree. Tree SB474 (N33 29.472, W81 59.082, elev. 55.8 m) exhibited > 66% crown loss and decaying roots with white mycelial fans and dark rhizomorphs characteristic of Armillaria. Tree SB913 (N33 29.830, W81 59.349, elev. 58.8 m) exhibited ca. 34-66% crown loss, while tree SB914 (N33 29.837, W81 59.338, elev. 57 m) appeared healthy with no apparent crown loss. Roots of trees SB913 and SB914 appeared healthy, although rhizomorphs were attached to the root surfaces. Roots and/or attached rhizomorphs were surface disinfested and plated n a basidiomycete-selective medium (Hendrix and Kuhlman 1962). Three Armillaria isolates, one from each corresponding tree, were paired with each other, and two genets were identified (SB474 and SB913 = SB914). The two genets (SB474 and SB913) were used in somatic pairing tests against three known tester isolates for each of the following species: A. solidipes, A. mellea, A. gallica, A. mexicana, and Desarmillaria caespitosa (=A. tabescens). Pairing of isolates SB474 and SB913 showed the highest compatibility with A. gallica (isolates ST22, ST23, and M70) with 100% and 89%, respectively. These isolates were definitively confirmed as A. gallica by translation elongation factor 1α gene sequences (tef1; Klopfenstein et al. 2017) (GenBank accession nos. OM993577 and OM993578 for SB474 and SB913, respectively). GenBank nucleotide BLAST showed tef1 similarity for both SB474 and SB913 isolates was highest for A. gallica (≥98.7%; GenBank accession nos. MT761696, MT761697, and KF156772). This is the first report of A. gallica associated with Armillaria root disease of C. laevigata. Rhizomorphs on the surface of apparently healthy tree roots and root colonization in severely declining trees are a common sign of A. gallica (Baumgartner and Rizzo 2001). Pathogen colonization of root surfaces may provide an opportunity for infection of highly damaged trees, resulting in root disease (Gregory 1985). Primary agents of C. laevigata dieback and mortality in SC and GA remain undefined, but continued study is needed to confirm the role of A. gallica in C. laevigata dieback and mortality. Although pathogenicity tests are impractical for Armillaria, these A. gallica occurrences in SC further adds to our knowledge of this pathogen's distribution in the southeastern USA, where it has also been confirmed in Tennessee in hardwood forests (Bruhn et al. 1997), SC on Hemerocallis sp. (Schnabel et al. 2005), and GA on a Rhododendron/span> sp. and Quercus rubra (Hanna et al. 2020). The distribution and host range of A. gallica is likely more widespread in the southeastern USA than existing records indicate. Documenting Armillaria distribution, including A. gallica, is essential for predicting climate-change impacts on Armillaria root diseases (Kim et al. 2022). Baumgartner, K., and Rizzo, D. M. 2001. Plant Dis. 85:947-951. Bruhn, J. N., et al. 1997. In 11th Central Hardwood Forest Conference, USDA, FS, NC-GTR-188, 49-57. Gregory, S. C. 1985. Plant Path. 34:41-48. Hanna, J. W., et al. 2020. Plant Dis. 105: 1226. Hendrix Jr, F. F., and Kuhlman, E. G. 1962. PI. Dis. Rep. 46:674-676. Kennedy, Jr., H. E. 1990. Silvics of North America: 2. Hardwoods. USDA-FS. Agriculture Handbook 654. Kim, M.-S., et al. 2022. Front. For. Glob. Change 4:740994. Klopfenstein, N. B., et al. 2017. Mycologia 109:75-91. Poole, E. M., et al. 2021. J. For. 119:266-274. Schnabel, G., et al. 2005. Plant Dis. 89:683.

Linking wood density records of common beech (Fagus sylvatica L.) with temperature and precipitation variability from a temperate lowland site.

European lowland beech stands are under pressure by current climate change and increased drought spells. Climate sensitivity of trees is most commonly studied by examining tree-ring width records and wood density-based time series, yet the potential of the latter is underexplored for hardwoods and beech (Fagus sylvatica L.) in particular. Here, we investigate how variability in radial growth, Maximum Latewood Density (MXD) and intra-annual wood density records in lowland beech are related to monthly and daily temperature (T) and precipitation (P) records, as well as the Standardized Precipitation Evapotranspiration Index (SPEI), during the past 50 years. 45 increment cores were collected from healthy (co-) dominant beech trees in Flanders (northern Belgium). We used X-ray micro-Computed Tomography (XµCT) to obtain wood density and tree-ring width series. By dividing every tree-ring into 4 sectors of equal radial width, we also assessed climatic forcings on intra-annual wood density variability (meanQi, i = 1:4). Water availability (SPEI) is the most important factor limiting radial growth, whereas MXD is correlated with summer temperature (period May-July, r = 0.334). Scanning resolution (110, 60, 20 µm) proves to be an important parameter when interpreting MXD values. We found that to quantify climate signals at the end of the growing season, density values should be representative for a relatively large part of the latewood. Our results also suggest that a sector approach is useful by showing climatic influences during the entire growing season. Wood density at the beginning of the growing season is mainly influenced by water availability (meanQ1∼SPEI, r = 0.416), whereas towards the end of the growing season only significant correlations with temperature were observed (meanQ4∼T, r = 0.347). We recommend to further explore MXD values for hardwood trees in lowland Europe.

Discovery of Fusarium proliferatum f. sp. malus domestica Causing Apple Replant Disease in China.

Apple replant disease (ARD) is the most serious threat facing the apple industry globally. ARD is mainly manifested as decreased plant growth, serious root rot disease, and considerable yield loss. Microbial factors are the dominant factors leading to the occurrence of ARD. Research on soil-borne pathogenic fungi leading to the occurrence of ARD in China is limited. In the present study, we selected 16 replanting orchards from the Northwest Loess region and around the Bohai Gulf. Diseased roots and rhizosphere soil from healthy apple trees and trees showing ARD symptoms were sampled at random. High-throughput sequencing was used to study the fungal communities in the rhizosphere soil, which showed that the composition of the rhizosphere soil fungal community of ARD-symptomatic and healthy apple trees was different. Nectriaceae at the family level and Fusarium at the genus level dominated the rhizosphere soil fungal community in the two regions, while for healthy apple trees, the relative abundance of Mortierella, Minimedusa, Tetracladium, and Chaetomium was higher. Tissue separation and serial dilution were used to separate fungi, and a total of 89 genera and 219 species were obtained, most of which were Fusarium. Fusarium was further confirmed to be the most abundant pathogen species leading to the occurrence of ARD in China through pathogenicity assays. A pathogenicity assay was carried out by the dip-and-cut technique using different host plants. It was found that Fusarium MR5 showed strong aggressiveness to apple rootstocks. Diseased seedlings specifically exhibited chlorosis of the leaves, browning from the edge of the leaf, followed by rolling and yellowing of the leaves, resulting in wilting and eventually death. Strain MR5 was preliminarily identified as F. proliferatum according to the morphological and cultural characteristics. A maximum likelihood analysis of identities based on six gene sequence (ITS, TUB2, IGS, mtSSU, RPB2, and the TEF gene) alignments between the MR5 strain and other strains showed 99 to 100% homology with F. proliferatum. Based on our test results, strain MR5 was identified as F. proliferatum f. sp. malus domestica, which is of great significance for finding new measures to control ARD in China.

First Record of Alternaria alternata causing necrosis of Thuja (Thuja occidentalis) in Kazakhstan.

Thuja is one of the ornamental plants used for landscaping parks and health resorts. The plant is distinguished by a pyramidal and conical crown shape and the presence of many thin branches with scale-shaped needles, green all year round. In addition, this plant has a number of antimicrobial properties, which affects the popularity of the plant in landscaping the health resort territory (Bakht et al. 2020, Chindyaeva et al. 2020). In January 2020, symptomatic Thuja plants were observed in Southern Kazakhstan. Symptoms included distortion of the crown. External examination of the trees revelaed the presence of white fluffy mycelium on Thuja branches. The branches acquired a yellow color with a necrotic lesion developing below the affected area. Samples of infected branches from different Thuja trees (n = 13) were collected. The infected branches were cut into small pieces (5 × 5 mm), washed in 70% ethanol for 30 min, and then rinsed three times with sterile distilled water. Later, these pieces were placed on Sabouraud's medium (Laboratorios Conda S.A., Spain) and incubated at 28°C for 7 days. Yellow-green colonies grew from the pieces of wood. The colonies had a light gray-whitish aerial mycelium. Conidia (n = 35) were pale to dark brown in color, irregular and ellipsoid to ovoid conical in shape. The size of the conidia varied from 5 to 25 µm × 6 to 12 µm (n = 40) with longitudinal and transverse septations. These morphological characters were previously described and corresponded to the Alternaria alternata (Simmons et al. 2007). Genomic DNA was extracted from mycelium using the liquid nitrogen and phenol-chloroform extraction method (Butler 2012). A 568 bp product of the Alt a1 gene and 472 bp product of the calmodulin protein-coding gene was amplified using following primer pairs Alt-for/Alt-rev (Hong et al. 2005) and CALDF1/CALDR1, respectively (Lawrence et al. 2013) (Integrated DNA Technologies, Inc., Coralville, IA, USA). The PCR reaction was done in a SimpliAmp thermal cycler (Applied biosystems, Waltham, MA, USA) under the following conditions: initial denaturation at 94 °C for 1 min, 35 cycles at 94°C for 30 s to denature, 57°C for 1 min for annealing, and 72°C for 1 min for extension. A final extension step at 72°C for 10 min was also included. The sequencing was done using BigDye® Terminator v3.1 Cycle Sequencing Kit (Applied Biosystems) and the sequence was deposited in GenBank with accession no. OL542696 calmodulin). These sequences were compared with other sequences in the GenBank by using the BLAST analysis (MZ222274.1 and MN473132.1). The phylogenetic analysis was carried out with MEGA 6 software (The Pennsylvania State University, University Park, PA, USA). To confirm the pathogenicity, 10 thuja branches from healthy trees from another area without visible pathologies were inoculated with a suspension of conidia (100 conidia/ml; obtained from 2-week-old cultures). Control samples were inoculated with sterile distilled water. The inoculated branches were placed in sterile plastic containers to maintain high humidity and incubated for 10 days at 28°C. After 7 days, irregular shaped lesions and fungal growth was observed at the site of inoculation. The affected area gradually increased in size with simioar symptomatology to that described above. Re-isolation of the pathogen and identification based on morphological features and sequencing confirmed the presence of the A. alternata pathogen. To our knowledge, this is the first report of A. alternata causing branches of thuja in Kazakhstan. Thuja is a rare plant species for this region; the cost and care are expensive. This case will allow timely diagnosis of the disease caused by Alternaria spp. in the future. It is necessary to develop preventive measures and a protocol for the treatment of thuja from a fungal infection. Bakht, J., 2020. Antibacterial activity of the crude extracts from medicinally important Thuja occidentalis. Pak J Pharm Sci. 33(2): 627-630. PMID: 32276908. Butler, J.M., 2012. Chapter 2 - DNA extraction methods. pp. 29-47 in Butler JM (Ed) Advanced topics in forensic DNA typing: Methodology. San Diego, Academic Press. doi: 10.1016/C2011-0-04189-3. Chindyaeva., L.N., et al. 2020. Comparative assessment of the phytoncidity of woody plants in the selection of species for landscaping: the possibility of use in sanatorium-and-spa practice. Vopr Kurortol Fizioter Lech Fiz Kult. 97(4): 44-51. Russian. doi: 10.17116/kurort20209704144. Hong, S.G. et al. 2005. Alt a1 allergen homologs from Alternaria and related taxa: analysis of phylogenetic content and secondary structure. Fungal Genet Biol 42:119-129. doi:10.1016/j.fgb.2004.10.009 Lawrence, D.P. et al. 2013. The sections of Alternaria: formalizing species-group concepts. Mycologia 105: 530-546. DOI: 10.3852/12-249. Simmons, E. G., 2007. Alternaria: An Identification Manual. CBS, Fungal Biodiversity Center, Utrecht, Netherlands.

Composition of Essential Oil of Healthy and Diseased Indian Rosewood Trees (Dalbargia Sissoo DC.)

The evergreen rosewood tree (Dalbargia sissoo or Indian rose wood tree), was once a major source of fuel wood and later used in the furniture industry, is now dying in a slow and mysterious death across Pakistan, India and other South Asian countries. In the present study chemical changes produced in essential oil of diseased Dalbergia sisso and chemical derivatization of essential oil were investigated to determine antioxidant and antitermitic activities. The potential ability of secondary metabolites present in disease affected trees was much lower to act as effective antioxidants to fight against oxidative damage. Results obtained showed that Tetradecane, Tertadecene and their derivatives present in Dalbergia sissoo trees play very vital role for keeping trees healthy. The Tukey HSD test, Scheffé, Bonferroni and Holm multiple comparison post-hoc tests clearly showed that Tetradecane and its derivative are significantly different in healthy and disease affected trees from each other. Bangladesh J. Bot. 51(3): 455-460, 2022 (September)

Strict substrate requirements alongside rapid substrate turnover may indicate an early colonization: A case study of Pleurotus calyptratus (Agaricales, Basidiomycota)

Pleurotus calyptratus is a wood-inhabiting oyster mushroom associated with Populus tremula and P. alba . This fungus is rather common in Ukraine, but considered rare in many other European countries. Aiming to find causes for variation in rarity, we conducted habitat mapping and repeated surveys to understand the substrate requirements and fruiting dynamics of P. calyptratus . We showed that fruiting is strictly associated with older trees and early decay stages, and not with physical properties of a tree trunk like volume or position. This timespan of substrate suitability lasts for 1–3 y, determining rapid substrate turnover. We also detected DNA of P. calyptratus in living tissues of visually healthy trees, meaning its latent presence in the hosts, which places the fungus in a position to be a pioneer in a fungal succession. Despite the high spatial and temporal variation in fruiting, five annual surveys demonstrated no significant trends in P. calyptratus population's dynamics, and supported the assumption of random variation in fruiting, driven mostly by dynamics of forest stands. Therefore, we hypothesize that P. calyptratus ' relative abundance in Ukraine is explained by continuous substrate supply from large homogenous aspen stands that are rare in the rest of Europe due to intensive management. • Pleurotus calyptratus shows yet unexplained differences in rarity across Europe. • Repeated fruit body surveys were applied to explore species population dynamics. • Latent development of P. calyptratus in young living trees has been proven. • P. calyptratus combines both strict requirements and rapid turnover of substrates. • Such fruiting pattern can indicate an early colonization strategy for agarics.

Fungal Communities in Re-Emerging Fraxinus excelsior Sites in Lithuania and Their Antagonistic Potential against Hymenoscyphus fraxineus.

Fifty-nine fungal taxa, isolated from re-emerging Fraxinus excelsior sites in Lithuania, were in vitro tested against three strains of Hymenoscyphus fraxineus on agar media to establish their biocontrol properties. All tested fungi were isolated from leaves and shoots of relatively healthy Fraxinus excelsior trees (<30% defoliation), which were affected by ash dieback but their phytosanitary condition has not worsened during the last decade. The inhibition of H. fraxineus growth by tested fungal taxa ranged between 16–87%. Occasionally isolated fungal taxa such as Neonectria coccinea, Nothophorma quercina, and Phaeosphaeria caricis were among the most effective fungi inhibiting the growth of H. fraxineus cultures. Among the more commonly isolated fungal taxa, Cladosporium sp., Fusarium sp., Malassezia sp., and Aureobasidium pullulans showed a strong growth inhibition of H. fraxineus.

MECHANICAL AND MICROSTRUCTURAL CHANGES IN POST-FIRE RAW WOOD

Introduction: Today, the need for the neutralization of the environmental, economic, social, and other consequences of natural emergencies is becoming more and more urgent. One of such devastating disasters is forest fires, which are currently very widespread in the world. In most cases, after a fire, we are left with a forest that was partially exposed to fire. A burnt tree loses its immunity. As a result, an outbreak of various subcortical insect species, which infect healthy trees as well, occurs in these territories. Such a forest is subjected to sanitary cutting. Purpose of the study: We aimed to determine the residual mechanical properties of raw wood to be used as a structural material. Methods: In the course of the study, we used destructive and non-destructive testing methods in respect of the mechanical properties of the material. Results: It was established that changes in the microstructure of wood correlate with its strength properties. The maximum decrease in the strength properties of wood was observed at the top end of the tree and amounted to 22.7% as compared to the reference wood. The minimum decrease in the strength properties of post-fire wood was observed in the butt end of the tree and amounted up to 15.0%. In the middle part, a decrease in the strength properties of wood was up to 24.0%.

SARUNGISASI BUAH KAKAO KLON MCC01 DAN MCC 02 DI KABUPATEN SOPPENG SULAWESI SELATAN

Cocoa production in South Sulawesi decreases from year to year one of the causes due to the attack of cocoa borer pests. The observations aimed to find out the effect of condomizing on MCC 01 and MCC 02, and to see which clones were resistant and more susceptible to PBK pest attacks through condomizing. The method of determining respondents is done deliberately and the determination of samples by determining cocoa tree samples deliberately by choosing a healthy tree and then condomized and without condemned by marking each sample tree. The results showed that condomizing can reduce cocoa fruit affected by PBK, attack rate and intensity of damage is classified as moderate, and MCC 02 is more resistant to PBK pests.

Stable isotopes reveal differences in climate sensitivity and physiological responses between dieback and healthy trees in a shelter forest

Tree-ring stable isotopes provide insights into the drought-induced eco-physiological mechanisms of forests. We investigated the growth of poplar and Mongolian pine trees decline in the Three-North Shelter Forest, and analyzed the differences in tree-ring width (TW), δ13C, δ18O, and intrinsic water-use efficiency (iWUE) between dieback and healthy trees. An R package was used to quantify the relative contributions of climatic and physiological factors to growth. Both TW and basal area increment were lower for the dieback poplar and Mongolian pine than for the healthy trees.δ13C, δ18O, and iWUE were higher for the dieback poplar than for the healthy individuals; there were no significant differences in Mongolian pine. The measured iWUE for healthy poplar, healthy and dieback Mongolian pine were consistent with the modeled iWUE for Ci/ Ca scenario, indicating the stomata were open and Ci increased along with Ca. In contrast, the measured iWUE was higher for the dieback poplar than for the healthy individuals, which was consistent with the constant Ci scenario and partial stomatal closure. A significant decreasing Ci/Ca was detected only for the dieback poplar, reflecting the diversity in the leaf gas-exchange strategies of the two species. Pearson coefficients showed that on the annual timescale, tree growth was significantly negatively correlated with temperature, VPD, and iWUE, but positively correlated with SPEI. Moreover, the relationships between TW and stable isotopes and stomatal regulation, which differed in the two species, were affected by the dieback process. Furthermore, iWUE andδ18O had the highest and lowest relative contributions to TW, respectively. The relative contribution of meteorological factors (Tem, VPD and SPEI) to the growth was significantly lower than that of physiological factors (iWUE and δ18O). Compared with the healthy controls of both species, the dieback trees were less sensitive to climate conditions, but the effects of physiological activities on growth were greater. These results provide a better understanding of the climate sensitivity and physiological responses of trees under long-term drought conditions.

Native pedunculate oaks support more biodiversity than non-native oaks, but non-native oaks are healthier than native oaks: A study on street and park trees of a city

Trees in cities provide multiple ecosystem services. However, simultaneously ensuring healthy trees with high habitat diversity can be challenging in a harsh urban environment. We compared health, microhabitats, and bat activities between native (Quercus robur L.) and non-native (Quercus rubra L.) oaks growing in different urban habitats (street vs. park) in Karlsruhe, southwestern Germany. We randomly selected 167 oak trees with a diameter at breast height (DBH) >20 cm across the city from Urban Tree Registrar. We performed tree health assessment, dendrometric, and microhabitat inventory. We recorded the four-day bat activities on 45 native and non-native oaks with acoustic loggers installed on the trees. We found that non-native oaks were healthier than native oaks but provided less abundance and richness of microhabitats. Tree size (positive effect) and pruning (negative effect) strongly influence microhabitat richness and abundance. In addition, park trees hosted significantly more microhabitats than street trees. We recorded the activities of 9 bat species from 4 genera. Pipistrellus bats were more active in park trees than street trees. Long-eared bats (Plecotus) were more active near the native than non-native oaks. Bats are likely favored by microhabitats such as fork split, lightning scar, and woodpecker “flute” that are more common in less healthy trees. We conclude that non-native red oak can be planted alongside streets, where the conditions are harsher than in parks to better adapt to climatic changes and stay healthy with less maintenance. The preservation of native pedunculate oak trees, especially within parks, is paramount for urban biodiversity conservation because of their potential to provide microhabitats and supporting bats.

Acoustic detection of stem and root borer Neoplocaederus ferrugineus (Coleoptera: Cerambycidae) in cashew

Block diagram of the proposed system. • Characterised the acoustic sounds of Neoplocaederus ferrugineus (Linnaeus) (Coleoptera: Cerambycidae). • There were no significant differences between the number of bursts and various larval instars. • Predicted the likelihood of infestation of N . ferrugineus and field evaluated the detection performance of the acoustic device. • This is the first work on the acoustic behaviour of cashew stem and root borer. Stem and root borer Neoplocaederus ferrugineus (Linnaeus) (Coleoptera: Cerambycidae) is a severe pest of cashew ( Anacardium occidentale L), which affects the cashew tree heavily. The larvae are tissue borers that remain concealed inside the tree and are very difficult to detect at the initial stage of infestation. Adult attractants are not identified, and manual checking of each tree in a plantation is not feasible and laborious. Acoustic technologies have been developed for the non-invasive and early detection of wood borers. The present study was conducted to characterize the acoustic sounds of various larval instars, tissues and field evaluation of the commercially available acoustic device. Burst analysis of different larval instars in cashew logs shows that there are no significant differences between the number of bursts and various larval instars. A relatively less number of bursts are found when the larvae are in the sapwood region than the cambium region. The empty cashew log and healthy trees do not produce any significant noise. The number of burst counts and impulses are used to predict the likelihood of infestation. The detection performance of the acoustic device under field conditions shows that infested trees are correctly detected with 91% accuracy. The possibility of not detecting healthy trees is 85%. This is the first report on the acoustic behaviour of cashew stem and root borer. The results of the study will help in better understanding the acoustic behaviour of the hidden pest and also be useful in the timely identification of stem and root borer-affected trees in cashew plantations.

Effects of Iron Rates on Growth and Development of Young Huanglongbing-affected Citrus Trees in Florida

Essential nutrients for citrus [‘Bingo’ (Citrus reticulata, Blanco)] production are important for different functions, including photosynthesis, resistance to disease, and productivity. During the past 15 to 20 years, citrus production in Florida has significantly declined as a result of the devastating citrus greening disease also called huanglongbing (HLB). Therefore, a greenhouse study was conducted for 2 years, starting in 2018, at the University of Florida/Institute of Food and Agricultural Sciences Citrus Research and Education Center in Florida to evaluate the effect of varying rates of iron on the growth and development of 2-year-old HLB-affected ‘Bingo’ (Citrus reticulata, Blanco) trees on Kuharske citrange rootstock. Four treatments were used in a randomized complete block (HLB status) design with seven single tree replicates for each treatment. The treatments applied were 0.0 (control), 5.6 (standard fertilization, lx), 11.2 (2x), and 22.4 (4x) kg⋅ha−1 iron on HLB-affected and healthy (non-HLB) citrus trees. Data including trunk diameter, tree height, and leaf samples were collected, processed, and analyzed at 3-month intervals for 2 years. At the end of the second year, trees were destructively sampled and processed as above-ground and below-ground biomass. Tree heights were different among iron rates of HLB-affected trees (P &lt; 0.001); however, they were similar for non-HLB trees for both years. Higher average trunk diameters (P &lt; 0.001) were observed for HLB-affected trees that received the 2x rate compared with the 1x rate and the control. In 2019, non-HLB trees showed 13% to 40% higher iron concentrations in leaves than HLB-affected trees. However, leaf iron concentrations were comparable for HLB-affected and non-HLB trees in 2020. Above-ground biomass for HLB-affected trees had between 33% and 44% more biomass (P &lt; 0.01) than below-ground biomass for the corresponding iron fertilization. Iron accumulation correlated positively with all studied nutrients in the above-ground parts for both HLB-affected and non-HLB trees. A 95% confidence interval at which total biomass was nearly maximum corresponded to an iron rate of 9.6 to 11.8 kg⋅ha−1, which was close to the 2x rate. Therefore, soil iron application using the aforementioned rates may be appropriate for better growth and development of young HLB-affected trees.

Isolation of Trichoderma virens 6PS-2 and its effects on Fusarium proliferatum f. sp. Malus domestica MR5 related to apple replant disease in China

Apple replant disease (ARD) is primarily caused by biotic factors that seriously inhibits the development of apple industry. Therefore, the use of biological control measures to inhibit the main pathogens (such as Fusarium spp.) that cause ARD is of great significance to the sustainable development of the apple industry. Trichoderma virens 6PS-2, which exhibited antagonism toward a variety of pathogens, was screened from the rhizosphere soils of healthy apple trees (Malusrobusta) in different replanted orchards in the Yantai and Zibo Cities, Shandong Province, China. Its fermentation extract inhibited the growth of pathogenic Fusarium proliferatum f. sp. Malus domestica MR5, which was proportional to the concentration. These substances also increased the hairy root volume and growth of Arabidopsis thaliana lateral roots. The phenotype of Malus hupehensis seedlings and microbial community structure in rhizosphere soils in greenhouse experiment using High-throughput sequencing were analyzed, and the field experiment with grafted apple trees were used for further verification. Compared with the application of potato dextrose broth (PDB) medium, application of 6PS-2 spore suspension directly to replanted soils could improve the growth of M. hupehensis seedlings as well as the elongation of grafted apple trees. Concomitant decreases in the gene copy number of Fusarium and increases in the culturable bacteria/fungi were also observed in the greenhouse and field experiments. The abundance of Trichoderma, Bacillus, and Streptomyces increased significantly, but that of Fusarium, Pseudarthrobacter, and Humicola decreased. The content of esters, phenols, furans, and amino acids in root exudates of M. hupehensis seedlings increased, which significantly inhibited the multiplication of Fusarium, but was positively correlated with Bacillus and Trichoderma. In summary, T. virens 6PS-2 not only directly inhibits the activity of pathogenic Fusarium but also secrets secondary metabolites with antifungal and growth-promoting potential. In addition, 6PS-2 spore suspension can also promote the growth of plants to a certain extent, and change the soil microbial community structure of rhizosphere soils. It is believed that T. virens 6PS-2 has the potential for the alleviation of apple replant disease (ARD) in China.

CNN–Aided Optical Fiber Distributed Acoustic Sensing for Early Detection of Red Palm Weevil: A Field Experiment

Red palm weevil (RPW) is a harmful pest that destroys many date, coconut, and oil palm plantations worldwide. It is not difficult to apply curative methods to trees infested with RPW; however, the early detection of RPW remains a major challenge, especially on large farms. In a controlled environment and an outdoor farm, we report on the integration of optical fiber distributed acoustic sensing (DAS) and machine learning (ML) for the early detection of true weevil larvae less than three weeks old. Specifically, temporal and spectral data recorded with the DAS system and processed by applying a 100–800 Hz filter are used to train convolutional neural network (CNN) models, which distinguish between “infested” and “healthy” signals with a classification accuracy of ∼97%. In addition, a strict ML-based classification approach is introduced to improve the false alarm performance metric of the system by ∼20%. In a controlled environment experiment, we find that the highest infestation alarm count of infested and healthy trees to be 1131 and 22, respectively, highlighting our system’s ability to distinguish between the infested and healthy trees. On an outdoor farm, in contrast, the acoustic noise produced by wind is a major source of false alarm generation in our system. The best performance of our sensor is obtained when wind speeds are less than 9 mph. In a representative experiment, when wind speeds are less than 9 mph outdoor, the highest infestation alarm count of infested and healthy trees are recorded to be 1622 and 94, respectively.