Behavioral and Neuronal Effects of Inhaled Bromine Gas: Oxidative Brain Stem Damage

The risk of accidental bromine (Br2) exposure to the public has increased due to its enhanced industrial use. Inhaled Br2 damages the lungs and the heart; however, adverse effects on the brain are unknown. In this study, we examined the neurological effects of inhaled Br2 in Sprague Dawley rats. Rats were exposed to Br2 (600 ppm for 45 min) and transferred to room air and cage behavior, and levels of glial fibrillary acidic protein (GFAP) in plasma were examined at various time intervals. Bromine exposure resulted in abnormal cage behavior such as head hitting, biting and aggression, hypervigilance, and hyperactivity. An increase in plasma GFAP and brain 4-hydroxynonenal (4-HNE) content also was observed in the exposed animals. Acute and delayed sympathetic nervous system activation was also evaluated by assessing the expression of catecholamine biosynthesizing enzymes, tryptophan hydroxylase (TrpH1 and TrpH2), and tyrosine hydroxylase (TyrH), along with an assessment of catecholamines and their metabolites. TyrH was found to be increased in a time-dependent manner. TrpH1 and TrpH2 were significantly decreased upon Br2 exposure in the brainstem. The neurotransmitter content evaluation indicated an increase in 5-HT and dopamine at early timepoints after exposure; however, other metabolites were not significantly altered. Taken together, our results predict brain damage and autonomic dysfunction upon Br2 exposure.

Effect of Fungus Meripilus giganteus (Pers.) P. Karst. on Occurrence and Development of False Heartwood and Rot in Fagus sylvatica L. Round Wood

Common beech is one of the most widespread and important European tree species, widely used in timber industry and for energy production. Under specific set of complex factors, it facutatetivly develops false heartwood, which considerably decreases market demand and value of processed logs. Due to its properties, false heartwood is more susceptible to attack of wood decay fungi, which leads to further loss of wood quality and value. One of the most common fungi able to cause heart rot in beech is Meripilus giganteus, known for its spread in the basal parts of the tree, where it can affect most valuable sections of round wood. The aims of this study were to monitor the distribution of fungus and appearance of its fruiting bodies in research area, and to analyze the extent of fungus impact on shape and size of false heartwood and occurrence and length of rot in infected trees, while taking into account the observed stem damage as a possible influential factor. Fruiting bodies occurrence, life span and position on a tree were monitored during a six-year period. For trees with confirmed infection, stem damage was evaluated and appointed to one of four size classes. False heartwood shape and share in associated stem cross-section were observed and measured on 1–4 cross-sections per tree at different heights, and compared between infected and uninfected trees. If present, length of wood decay extent on butt-log was measured. The obtained results confirmed increased susceptibility of mature trees to infection, which seemed to occur mostly via roots from where mycelium spread into stem base. It was found that Meripilus giganteus has a significant impact on enlargement and change of FH shape from cloud- to star-like, up to approximately 5 m of the stem height, thus causing devaluation of the first assortments. The presence of rot was confirmed on the majority of infected trees, extending averagely 0.5 m into the first processed log, causing the loss of utilizable volume and thus the value of round wood. Stem damage category showed no significant effect on false heartwood or rot, supporting the prevailing impact of the fungus.

Design and Operating Parameter Optimization of a Harvester for Efficient Lily Bulb Cultivation

Highlights An urgent need exists to mechanize lily harvesting to meet growing demand. A new lily bulb harvester suited to the agronomy of lily planting sites in China was designed. Operation parameters were optimized and validated via field tests. Bulb loss and stem damage rates of 2.31% and 1.82%, respectively, were achieved. Abstract . At present, lily bulbs are harvested primarily by manual excavation in most countries, whereas harvesting machinery is used for other tuber and rhizome crops. However, this approach results in several problems, such as high manual excavation costs, low efficiency, and incomplete separation of soil and lily bulbs. To address these problems, we propose a harvesting machine designed specifically for lily harvesting. Our design process involved measuring and analyzing the physical and mechanical properties of soil and lily bulbs during the harvest period, designing key mechanical components through theoretical calculations, and performing a single-factor simulation of the harvesting process to determine the test value range of each factor. We considered the bulb loss and stem damage rates as evaluation indicators and the machine forward speed, elevator linear speed, and elevator inclination as test factors. We conducted a three-factor, three-level rotation combined test, and the working parameter values were optimized according to the regression analysis results. The test results show that for a forward speed, linear elevator speed, and elevator inclination of 1.4 m/s, 1.8 m/s, and 25°, respectively, the bulb loss and stem damage rates were limited to 2.31% and 1.82%, respectively, thus maximizing the quality and yield of the harvest. Field experiment results showed that the optimized results were consistent with the experimental results and met the requirements of lily harvesting. Keywords: Harvester, Rhizome harvesting, Lily cultivation, Lily bulb properties, Soil parameters, Simulation analysis.

Interaction between stem damage, crown vitality and growth performance of European yew in Central–East Europe

As long-lived, slow-growing tree species, European yew (Taxus baccata L.) has considerable potential for dendrochronological use. The increasing probability of decline and the worsening of yew health status endanger the species diversity of temperate forests. In 2015–2017, we sampled adult yew populations with scattered occurrence in limestone beech forests (Fagetum dealpinum), in which yew trees exhibit the top growth performance. Altogether, 150 trees were sampled (294 cores) at four localities. By using the general linear model, we investigated the interactions between stem and crown status, sex and growth performance of yew trees. Based on the previous results and innovative measures of competition and canopy closure, we explored the promotion of silviculture care for female over the male trees and formulated exact release cutting rules. The results demonstrate divergent growth trends between male and female trees and the pronounced negative effects of crown and stem damage on growth performance of European yew. Expected decreases in radial growth of damaged female trees in comparison with male ones is less confirmed. Despite this, making silvicultural treatments for females as a priority is recommendable. Our findings can improve the effectiveness of forest management and restoration activities in European temperate forests, where yew adults are threatened by the higher degree of shading and herbivory pressure.

Resistance to Anthracnose (Colletotrichum lentis, Race 0) in Lens spp. Germplasm

Anthracnose, caused by the fungal pathogen Colletotrichum lentis, is a severe disease of lentil (Lens culinaris) causing premature defoliation, necrotic stem lesions that lead to plant wilting and death in susceptible varieties. Two races of C. lentis (0 and 1) have been described so far. Race 0 is the most virulent one and limited genetic resistance is available to date. To address this scarcity of resistance, we screened a germplasm collection covering different Lens spp. originating from different countries for C. lentis race 0 resistance. Leaf and stem damage and plant mortality were assessed on seedlings inoculated under controlled conditions. A significant variability was observed among accession. Most of the collection studied was highly susceptible, but some levels of resistance were identified in about 15% of the accessions. The highest levels of resistance were identified in L. ervoides accessions PI572330, PI572334 and PI572338. Moderate resistance was also identified in 10 L. culinaris ssp. culinaris accessions but not in the remaining species studied. Selected accessions showed potential to integrate several breeding programs.

Reaction to release treatments and distinctive attributes of butternut that promote resistance to the canker caused by Ophiognomonia clavigignenti-juglandacearum

This research examines the impact of light and tree attributes of butternuts, including bark phenotype, on their health. Some butternuts were released by thinning the crowns of neighbouring trees in two locations in Québec, while others were not. Various butternut characteristics related to their health that had been collected by a partner in the Montérégie region are also analysed. The release treatment did not have any significant impact on any health variables. However, their location, the diameter increments before releasing trees and twig collection on some butternuts had a significant impact on some of these variables. For the butternuts of the Montérégie region, their position in the canopy had a significant impact on main stem damage and on the putative resistance to the canker caused by Ophiognomonia clavigignenti-juglandacearum; trees from the upper storey were healthier. Dieback of dark and deep furrowed bark phenotype butternuts was significantly lower than that of the light, shallow furrowed bark ones. Butternuts with a greater annual increase in basal area had better vigour. This was greater in the upper canopy and among the deep furrowed bark butternuts.

A systematic review of the direct and indirect effects of herbivory on plant reproduction mediated by pollination

Background Plant reproduction is influenced by the net outcome of plant–herbivore and plant–pollinator interactions. While both herbivore impacts and pollinator impacts on plant reproduction have been widely studied, few studies examine them in concert. Methodology Here, we review the contemporary literature that examines the net outcomes of herbivory and pollination on plant reproduction and the impacts of herbivores on pollination through damage to shared host plants using systematic review tools. The direct or indirect effects of herbivores on floral tissue and reported mechanisms were compiled including the taxonomic breadth of herbivores, plants and pollinators. Results A total of 4,304 studies were examined producing 59 relevant studies for synthesis that reported both pollinator and herbivore measures. A total of 49% of studies examined the impact of direct damage to floral tissue through partial florivory while 36% of studies also examined the impact of vegetative damage on pollination through folivory, root herbivory, and stem damage. Only three studies examined the effects of both direct and indirect damage to pollination outcomes within the same study. Conclusions It is not unreasonable to assume that plants often sustain simultaneous forms of damage to different tissues and that the net effects can be assessed through differences in reproductive output. Further research that controls for other relative drivers of reproductive output but examines more than one pathway of damage simultaneously will inform our understanding of the mechanistic relevance of herbivore impacts on pollination and also highlight interactions between herbivores and pollinators through plants. It is clear that herbivory can impact plant fitness through pollination; however, the relative importance of direct and indirect damage to floral tissue on plant reproduction is still largely unknown.

Stem Damage Modifies the Impact of Wind on Norway Spruces

Bark stripping caused by cervids can have a long-lasting negative effect on tree vitality. Such trees of low vitality might be more susceptible to other disturbances. The amplifying effects of disturbance interactions can cause significantly more damage to forest ecosystems than the individual effects of each disturbance. Therefore, this study aimed to assess the impact of bark stripping (stem damage) on the probability of wind damage and snapping height for Norway spruces (Picea Abies (L.) H. Karst.). In this study, we used the Latvian National Forest Inventory data from the period 2004–2018. In the analysis, we used data based on 32,856 trees. To analyse the data, we implemented a Bayesian binary logistic generalised linear mixed-effects model and the linear mixed-effects model. Our results showed that stem damage significantly increased the probability of wind damage and affected the snapping height of Norway spruces. Similarly, root damage, the slenderness ratio, the stand age, the stand density, the soil type, and the dominant tree species had a significant influence on the probability of wind damage. In both periods, trees with stem damage had significantly (p < 0.05) higher probability (odd ratio 1.68) to be wind damaged than trees without stem damage. The stem damaged Norway spruce trees snapped in the first 25% of the tree height, while trees without stem damage snapped around half (50%) of the tree height. Our results show that stem damage significantly alters the effect of wind damage on Norway spruces, suggesting that such damage must be incorporated into wind-risk assessment models.

Economic Injury Level for Bermudagrass Stem Maggot (Diptera: Muscidae) in Bermudagrass Forage Production in Texas

The bermudagrass stem maggot, Atherigona reversura Villeneuve (Diptera: Muscidae), was first reported damaging bermudagrass Cynodon dactylon (L.) Pers grown for forage in 2010 in the southeastern United States. Injury results from individual larvae feeding internally on the vascular tissue just above the terminal node of the grass stem. Injury slows plant growth and reduces forage accumulation. To address the need for economic guidelines to manage this new pest, the relationship between the percent of stems damaged by bermudagrass stem maggot and forage yield was measured in commercial bermudagrass hay fields in northcentral Texas. Yield loss was estimated to be 9.97 kg/ha (8.90 lbs /acre) for each percentage of stems with bermudagrass stem maggot damage. This relationship was used to calculate economic injury levels for a range of hay market values and control costs. The impact of stem damage on protein content, energy, and digestibility of bermudagrass hay was also investigated. Although there was a significant trend for declining forage quality with increasing stem damage, stem damage explained very little of the model’s variability.