Stem Sap Research Articles

Influence of Organic Nutrient Sources on Nutrient, Quality and Yield Parameters of Vegetable Cluster Bean

Aim: The experiment was taken up to study the influence of various organic nutrient sources on soil nutrient availability and their uptake and also on quality parameters of vegetable cluster bean. Place and Duration of Study: the study was conducted at irrigated wetland farms, TNAU, Coimbatore during the year 2018. Methodology: The RBD (randomized complete block design) design was adopted and replicated thrice. The total number of treatments were 12 with various basal applications of organic manures namely farm yard manure, vermicompost, humic acid, ghanjeevamrutham and also foliar spray combinations namely panchagavya and banana pseudo stem sap. The standard recommended cultural practices of organic farming were followed for all treatments except fertilizer application and synthetic chemical use. Results: The data revealed that soil chemical properties viz., pH, EC and organic carbon were not significantly influenced by various organic nutrient sources. Significantly, higher values of N, P and K availability in soil and their uptake by cluster bean crop and crude protein content, crude fiber, ascorbic acid, moistures percentage in cluster bean pods were recorded with 100 % recommended dose of fertilizer and 2% foliar spray of TNAU pulse wonder. However, organic treatments were on par with inorganic treatments for all the nutrient, quality and yield parameters. Conclusion: Organic treatments like organic farmers practice and FYM along with Panchagavya were recommended to improve nutrient use efficiency and quality of yield, eventually to benefit farmers and complete agricultural ecosystem in terms of profit and sustainability, respectively.

Comparative analysis of water-use strategies in three subtropical mangrove species: a study of sap flow and gas exchange monitoring.

Water-use strategies play a crucial role in the adaptive capabilities of mangroves to the saline intertidal conditions, yet the intricacies of daily water-use patterns in mangrove species, which are pivotal for maintaining water balance, remain poorly understood. In this comprehensive study, we aimed to clarify the water use strategies of three co-occurring mangrove species, Avicennia marina, Aegiceras corniculatum and Kandelia obovata, through stem sap flow monitoring, leaf gas exchange and stem diameter change measurements. Our findings revealed that the daily sap flow density of Avicennia and Aegiceras reached the peak about 1 h earlier than that of Kandelia. When transpiration was strong, Kandelia and Aegiceras used stem storage to meet water demand, while Avicennia synchronized stem water storage. These three mangrove species adopted cross-peak water used and unique stem water storage to regulate their water balance. In Kandelia, the daily sap flow in per sapwood area was significantly lower, while water-use efficiency was significantly higher than those of Avicennia and Aegiceras, indicating that Kandelia adopted a more conservative and efficient water-use strategy. Sap flow in Avicennia was the most sensitive to environmental changes, while Kandelia limited water dissipation by tightly controlling stomata. Meteorological factors (photosynthetically active radiation, vapor pressure deficit and air temperature) were the main driving factors of sap flow. The increase of soil temperature can promote the water use of mangrove species, while the increase of salinity resulted in more conservative water use. Our results highlight the diversity of daily water-use strategies among the three co-occurring mangrove species, pinpointing Kandelia as the most adaptive at navigating the changing conditions of intertidal habitats in the future climate. In conclusion, our findings provide a mesoscale perspective on water-use characteristics of mangroves and also provides theoretical basis for mangroves afforestation and ecological restoration.

Agapanthus allergic contact dermatitis: A case report

Background: Agapanthus (Lily of the Nile) is a genus in the flowering plant family Amaryllidaceae. Contact dermatitis caused by flowering plants is common, but there are no reports of contact dermatitis caused by this plant, Agapanthus. Case Illustration: An 82-year-old Japanese man had cultivated Agapanthus in his home garden. After breaking the stem of the leaf while wearing shorts, he noticed erythematous rashes on the thighs. The patch test of the leaf stem sap “as is” showed mildly positive, with erythematous papules. Discussion: The patch test confirmed the allergic contact dermatitis of Agapanthus with leaf stem sap. There are many well-known flowering plants, like lilies, daisies, jasmine, orchids so on, that can cause contact dermatitis. To date, many people fold Agapanthus flowers and decorate them at home, so far, this plant should also be added to the causative plant for contact dermatitis. Conclusion: To the best of our knowledge, there are no reports of contact dermatitis caused by this plant. Agapanthus contact dermatitis will need to be brought to people’s attention.

Antibacterial activity of Betadine ( Jatropha multifida L.) stem extract on Pseudomonas aeruginosa growth invitro.

Today, people use plants to treat various types of diseases and improve human health. One of the medicinal plants is the Betadine plant ( Jatropha multifida L.). Betadine plants have many functions, especially the sap, leaves, fruit and seeds. The compound contents in Betadine stem sap, which is efficacious as an antimicrobial, are saponins, tannins, flavonoids and labaditin. One of the bacteria that cause infection is Pseudomonas aeruginosa. These bacteria can cause opportunistic and nosocomial infections. This study was a true experimental laboratory with a post-test only control group design. This study used Betadine stem sap extract with concentrations of 25%, 50%, 75%, 100%, gentamicin cream 10% as positive control, and dimethyl sulfoxide (DMSO) solution as negative control. This study used the Kirby-Bauer diffusion method and the bacterium Pseudomonas aeruginosa was grown on nutrient agar media, then incubated for 24 hours and calculated using calipers. Research data were analyzed using one-way ANOVA test. The highest inhibition zone was group 50% (12.725 ± 0.2500 mm) while the lowest inhibition zone was group 100% (8.675 ± 0.5620 mm). Betadine stem extract had antibacterial activity in inhibiting the growth of Pseudomonas aeruginosa bacteria, with the 50% concentration being the most effective in inhibiting the growth of Pseudomonas aeruginosa bacteria.

The utilization of medicinal plants in Kolaka local community: An ethnobotanical study

This research aims to find out, document, and analyze traditonal knowledge regarding plant types, processing methods, and compound contents used by the community in Kolaka District for wound healing treatments. The research method used is descriptive qualitative. The data collection techniques used observation and interviews. The results of this research show that there are 18 types of plants that are used as wound medicine in the community of Kolaka District with various methods of utilization, including grinding beans/seeds and leaves, extracting sap or essence from leaves, and using the plant stem sap, that is later applied to the injured parts of the body. The results of this research are expected to contribute academically to the field of ethnobotany, particularly concerning the utilization and developments of new medicines for various types of wounds on the body using natural ingredients, in order to anticipate dependence on chemical drugs or antibiotics which often have the potential to cause side effects. Additionally, through documenting types of plants and traditional wound treatment methods in this research, it is hoped that the preservation and originality of local knowledge regarding longstanding healthcare system within the community can be maintained.

REVIEW KARAKTERISTIK SORGUM MANIS (Sorghum bicolor L. Moench) SEBAGAI BAHAN BAKU PRODUKSI BIOETANOL

Sweet sorghum (Sorghum bicolor L. Moench) is a cereal plant that is able to grow in a relatively harsh environment and can be cultivated in Indonesia even though it is not a tropical plant. This plant has the potential to be used as raw material in making bioethanol because in addition to being environmentally friendly, the raw materials are also very abundant, so it can be an alternative substitute for gasoline. The weight of the stem biomass, the percent of brix nira, and the volume of sap contained in the superior genotype of sweet sorghum for bioethanol production. The results obtained from stem biomass, percent brix in stem sap, and high volume of sap can be used as criteria for selecting varieties for bioethanol raw materials from sweet sorghum.

Instantaneous sap flow velocity simulation of Euonymus bungeanus based on neural network optimization model.

The sap flow of trees is complex and difficult to express with multivariate linear or empirical models. A simple and feasible method on the basis of understanding sap flow variation to simulate its variation with environmental factors is of special importance for quantitatively analyzing forest ecohydrological processes and regional water demand. In this study, with one of the shelter forest species Euonymus bungeanus in the east sandy land of Yellow River in Ningxia as the research object, we continuously measured the trunk sap flow velocity by thermal diffusion sap flow meter, and analyzed the effects of environmental factors on stem sap flow. We used the particle swarm optimization (PSO) and sparrow search algorithm (SSA) optimized neural network model to predict sap flow velocity of E. bungeanus. Results showed that the main environmental factors influencing sap flow were solar radiation, vapor pressure deficit, air temperature, and relative humidity, with the influencing importance of 32.5%, 25.3%, 22.0% and 16.1%, respectively. The response process between sap flow and environmental factors presented a hysteresis loop relationship. The optimized BP, Elman and ELM neural network models improved the comprehensive evaluation index (GPI) by 1.5%, 30.0% and 5.3%, respectively. Compared with the PSO-Elman and SSA-ELM optimization models, the SSA-BP optimization model had the best prediction results with an improvement of 1.0% and 23.2% in GPI, respectively. Therefore, the prediction results of the BP neural network model based on the sparrow search algorithm could be used as an optimal model for predicting instantaneous sap flow velocity of E. bungeanus.

Features of Scots Pine Mortality Due to Incursion of Pine Bark Beetles in Symbiosis with Ophiostomatoid Fungi in the Forest-Steppe of Central Siberia

Forest decline is a significant issue affecting critical ecosystem processes worldwide. Here, we describe mortality in Pinus sylvestris L. monitored trees caused by the inhabitation of pine bark beetles (Tomicus minor Hart.) in symbiosis with ophiostomatoid fungi (Ophiostoma piceae (Munch) H. et P. Sydow) infection in the forest-steppe of central Siberia. Stem sap flow (Q) and stem diameter fluctuations (dRc) were monitored in eight pine trees during seven consecutive growing seasons (2015–2021). In addition, microcore sampling every ten days allowed the determination of stem wood formation in monitored trees in the 2021 growing season. During 2020 and 2021, two cases of Q termination were recorded among the monitored trees, with microcores revealing no cambium formation. Thus, the seasonal Q onset matches the beginning of the beetle dispersal period when they attack and inhabit tree stems. The decline of circumferential stem size began 10–12 days after Q onset, during the massive inhabitation of beetles into the stems. The disturbance of Q in trees occurred in 21–23 days, and total cessation of Q was observed 23–26 days after the Q onset at the beetle’s egg development phase. The timing of dRc disturbance and Q cessation observed directly coincides with the beetle life cycle. Thus, the phenology of pine trees and T. minor beetles is driven by seasonal weather conditions, particularly the cumulative air temperature (>0 °C).

Stem sap flow of Haloxylon ammodendron at different ages and its response to physical factors in the Minqin oasis-desert transition zone, China

Stem sap flow of Haloxylon ammodendron at different ages and its response to physical factors in the Minqin oasis-desert transition zone, China

Pendampingan Pembuatan Gula Merah Berbahan Nira Batang Kelapa Sawit di Desa Sei Musam, Kecamatan Sei Batang Serangan

Community service is carried out as part of the implementation of the Tri Dharma of Higher Education which aims to assist the community in increasing knowledge and skills in the field of making brown sugar that utilizes the sap of palm oil stems. Oil palm stem sap can be processed into brown sugar which is an alternative for processing palm oil waste in Sei Musam Village, Sei Batang Serangan District, Langkat Regency. The method of implementing this community service activity is in the form of assistance to brown sugar producers in the form of technology transfer, management, and equipment support. Assistance activities carried out for 2 (two) days. The result of the mentoring activities is an increase in palm sap processing skills, and an increased understanding of business management, especially in financial governance with simple bookkeeping. Assistance to brown sugar artisans needs to be done considering the quality of brown sugar produced so far is still low and the shape of the brown sugar produced is not uniform. The assistance team provided equipment in the form of a brown sugar molding tool to produce a uniform brown sugar mold so that when it is packaged it looks neat for marketing. From the community service activities that have been carried out, it shows that the craftsmen are able and successful in making brown sugar uniform shapes and are able to calculate the cost of producing brown sugar from palm oil stem sap.

Jatropha multifida L stem sap gel versus Aloe vera gel to post-gingivectomy healing process

Introduction: Gingivectomy is cutting the gingiva during a gingival enlargement condition that causes an open wound in the gingiva. Jatropha multifida L gel contains active ingredients of alkaloids, flavonoids, saponins and tannins, which are thought to accelerate the wound healing process, but its use in dentistry is limited. The objective of this research is to determine the effectiveness of the application of Jatropha multifida L stem sap gel in the wound healing process post-gingivectomy in Wistar rats (Rattus novergicus) compare with Aloe vera gel (Aloe Barbadensis Miller) by using parameters the number of fibroblasts, blood vessels and the density of collagen fibers Methods: Rats were divided into 4 groups, namely group K (Aloe vera gel), P1 (Jatropha multifida L stem sap gel 2,5%), P2 (Jatropha multifida L stem sap gel 5%) and P3 (Jatropha multifida L stem sap gel 10%). Each group was given the gel twice a day in the wound area; then the wound was observed microscopically by Haematoxylin Eosin staining to count the number of fibroblasts and blood vessels also Masson Trichrome staining to observe the density of collagen fibers on day 3 and 7. Results: The data obtained were statistically analyzed using the One Way Anova, Dunnet and Kruskal-Wallis test. One Way Anova test shows there is a significant difference (p<0.05) in the number of fibroblasts, and the Dunnet test shows there is a significant difference (p<0.05) in the number of fibroblasts in Jatropha multifida L stem sap gel group 2.5% and 5 % on day 3. One Way Anova test shows no significant difference (p>0.05) in the number of blood vessels. The Kruskal-Wallis test shows no significant difference (p>0.05) in collagen fiber density. Conclusion: Jatropha multifida L Stem Sap gel has the same potential as Aloe vera gel in accelerating wound healing after gingivectomy in Wistar rats.

Green mass productivity and quality of new sweet sorghum varieties in the ARC “Donskoy”

Introduction. In order to realize productive potential of any crop, a variety is of great importance. There is a number of requirements imposed on modern varieties, including not only productivity and quality, but alsocompliance with environmental and climatic conditions, resistance to unfavorable conditions, adaptability to mechanized harvesting. The purpose of the current work was to identify effective methods for developing sweet sorghum varieties, to estimate the sweet sorghum varieties developed by the Agricultural Research Center “Donskoy”” according to productivity and quality of green mass for silage. Methods. The paper presents the study results on the development and research of new sweet sorghum varieties in the Agricultural Research Center “Donskoy”” (Rostov region) through the years 2019–2021. The soil was an ordinary carbonate chernozem, with 3.6 % of humus in the arable layer. The objects of the study were sweet sorghum varieties. The ways to conduct trials, soil tillage and cultivation, as well as zootechnical analysis of green mass were determined according to generally accepted methods. Results. When developing a new variety, a number of characteristicsneeds to be taken into account according to which breeding is carried out from year to year, namely suitability for mechanized harvesting, stem succulence, tillering, stem diameter, length of a vegetation period, sugar content in stem sap, productivity and its main elements, etc. There are such methods for developing sweet sorghum varieties in the Agricultural Research Center “Donskoy”” as hybridization, incubation and selection of constant forms. As a result of the breeding work, there has been developed a number of varieties. In the State List there are 5 varieties of the Agricultural Research Center “Donskoy””. Green mass productivity of the new varieties Yuzhnoe and Feniks was 36 and 42 t/ha, respectively. The sugar-protein ratio of the variety Feniks was normal (1.1 : 1). Silage is recommended to be combined with protein cultures. The yield of exchangeable energy in green mass for silage (for cattle) obtained from new sweet sorghum varieties was 13.5–14.1 MJ/ha.

Below canopy evapotranspiration in four different variable retention harvesting treatments in a red pine plantation forest

AbstractVariable retention harvest (VRH) is a silvicultural approach that retains differing proportions and patterns of canopy trees across a harvested area to emulate natural disturbance effects on stand structure and enhance the resilience of the regenerating stand to abiotic and biotic stresses. Four VRH treatments were applied to an 83‐year‐old red pine (Pinus resinosa Ait.) plantation forest in the Mixedwood Plains Ecozone of Canada that included 55% aggregate retention (55A), 55% dispersed retention (55D), 33% aggregate retention (33A), 33% dispersed retention (33D) and an unharvested control (CN). In the sixth growing season after harvest, tree stem sap flow and eddy covariance flux measurements were used to examine the impacts of VRH on the dominant components of total stand evapotranspiration (ET), i.e., canopy transpiration (TC) and water flux from the understory vegetation and soil (ETU) as well as understory and canopy water use efficiency (WUE). A positive relationship was found between harvest intensity and the growth of understory vegetation and ETU. The contribution of ETU to ET was higher in the dispersed compared to the aggregate VRH treatments. Canopy transpiration contributed 83% of ET in the CN plot and 58%, 55%, 30% and 23% in the 55D, 55A, 33A and 33D treatments, respectively. Overall, VRH treatments resulted in increased canopy WUE but little comparative effect on understory WUE. Our results suggest that the dispersed retention pattern led to higher ET and productivity than the aggregate pattern of the same retention level. Where carbon sequestration and climate change mitigation is the primary management objective, higher retention levels such as 55D might be used to favour stand level carbon storage while accepting slower rates of understory development. Our findings on the effects of VRH on productivity and WUE of the canopy and understory will help forest managers to better employ VRH as an option to meet multiple objectives and adapt forests to a warmer, more variable climate.

Comparative growth, hydraulic conductivity, and sap flow responses of seedlings of two pyrus species to drought stress

Drought is one of the major abiotic stresses limiting the advancement of the pear industry in the arid and semiarid regions of China. Currently, the production of pear seedlings mainly depends on the grafting propagation of rootstocks from Pyrus betulaefolia Bunge and Pyrus calleryana Decne. However, limited information is available on the drought stress potential of these rootstocks. Here, we conducted pot experiments with controlled watering conditions on both rootstocks' seedlings and compared their growth, plant hydraulic conductivity, and stem sap flow velocity. Both rootstocks' seedlings were challenged with three drought regimes i.e. light (LD), moderate (MD), and heavy (HD) drought stress. The results indicated that P. betulaefolia performed better in growth than P. calleryana under the same drought regimes. Under LD, MD, and HD the relative growth of the new shoots, leaf-specific canopy hydraulic conductivity, leaf, stem, and root hydraulic conductivity, and stem sap flow velocity of P. betulaefolia exhibited reduction as compared to control (CK). Similar reduction trends were noted for P. calleryana, with slight variations in the case of stem-specific canopy hydraulic conductivity.

Study on the Dynamics of Stem Sap Flow in Minqin Wind and Sand Control Haloxylon ammodendron Forest, China

In this study, we obtained real-time data on the stem fluid flow of Haloxylon ammodendron in the growing season in Minqin, China, based on thermal diffusion (TDP) monitoring technology, and analyzed the dynamic changes of stem fluid flow in it to provide important supporting evidence for understanding the water consumption of H. ammodendron during its growth. The results indicate that the fluid flow in the stem of the H. ammodendron increases with increasing growth age and also decreases as the H. ammodendron grows older and declines. The average daily sap flow rates of H. ammodendron stems were 0.956, 1.059, 1.460 and 0.570 cm3·(cm2·h)−1 at 5, 10, 15 and 20 years, respectively, and the cumulative sap flow masses during the growing season from May to October were 610.173, 423.386, 1041.186 and 430.212 kg, respectively. H. ammodendron stem sap flow increases with the thickening of H. ammodendron’s ground diameter. The average daily sap flow rate of H. ammodendron stems at different stem levels ranged from 0.276 to 2.132 cm3·(cm2·h)−1, and the cumulative sap flow mass during the growing season ranged from 121.656 to 1722.810 kg. The larger the diameter of the H. ammodendron at different forest ages, the earlier the sap flow initiation time and the higher the peak. The stem flow initiation time was 7:00–8:00, and the average daily maximum fluid flow rate was 2.493–5.536 cm3·(cm2·h)−1, with the peak occurrence time advancing with age. The sap flow variation of H. ammodendron at different stand ages reflects the water-consuming process of H. ammodendron growth and its response to a drought environment, while the sap flow variation of H. ammodendron at different diameter classes shows that the individual growth differences of H. ammodendron also yield obvious competitive advantages. The results of the analysis can provide theoretical support for the estimation of ecological water use in desert H. ammodendron sand-fixing forests.

Enhanced Isohydric Behavior Decoupled the Whole-Tree Sap Flux Response to Leaf Transpiration under Nitrogen Addition in a Subtropical Forest

Anthropogenic nitrogen deposition has the potential to change the leaf water-use strategy in the subtropical region of China. Nevertheless, the whole-tree level response crucial for the ecosystem functions has not been well addressed over the past decades. In this study, the stem sap flux density (JS) was monitored for the whole-tree water transport capacity in two dominant species (Schima superba and Castanopsis chinensis) in a subtropical forest. To simulate the increased nitrogen deposition, the NH4NO3 solutions were sprayed onto the forest canopy at 25 kg ha−1 year−1 (CAN25) and 50 kg ha−1 year−1 (CAN50), respectively, since April 2013. The JS and microclimate (monitored since January 2014) derived from the whole-tree level stomatal conductance (GS) were used to quantify the stomatal behavior (GS sensitive to vapor pressure deficit, GS-VPD) in response to the added nitrogen. The maximum shoot hydraulic conductance (Kshoot-max) was also measured for both species. After one-year of monitoring in January 2015, the mid-day (JS-mid) and daily mean (JS-mean) sap flux rates did not change under all the nitrogen addition treatments (p > 0.05). A consistent decline in the GS-VPD indicated an enhanced isohydric behavior for both species. In addition, the GS-VPD in the wet season was much lower than that in the dry season. S. superba had a lower GS-VPD and decreased JS-mid/JS-mean, implying a stronger stomatal control under the fertilization, which might be attributed to the low efficient diffuse-porous conduits and a higher JS. In addition, the GS for S. superba decreased and the GS-VPD increased more under CAN50 than that under CAN25, indicating that the high nitrogen dose restrains the extra nitrogen benefits. Our results indicated that the JS for both species was decoupled from the leaf transpiration for both species due to an enhanced isohydric behavior, and a xylem anatomy difference and fertilization dose would affect the extent of this decoupling relation.

Using infrared thermal imaging technology to estimate the transpiration rate of citrus trees and evaluate plant water status

Crop transpiration is the main dissipation way of agricultural water. Accurate and effective estimation of crop transpiration is of great significance for the study of the carbon-water cycle relationship and efficient water-saving irrigation. This study uses infrared thermal imaging technology to accurately extract the average temperature of the plant canopy as a key input for the new model (three-dimensional temperature (3D-3T) model), which is an extension of the three-temperature (3T) model and applied to estimate the canopy transpiration rate of typical citrus trees (variety named Guoqing No. 1) from 8:00 to 18:00 on May 7 to 11, 2021. And a processing method for extracting green plants in visible-light images based on the Normalized Difference Ratio Index (NDRI) is proposed for the first time, which can distinguish green plants from other ground objects, backgrounds, and shadows in the visible-light image, and then help to accurately extract the average canopy temperature from infrared thermal images. For this experiment, the canopy structure characteristics of the selected experimental subjects and the measurement methods used were considered, so the 3D-3T model was converted to a 5-point three-temperature model (5P-3T model) to estimate the canopy transpiration rate of citrus trees and evaluate the plant water status, and then the sap flow measurement was used for validation. The results showed that: (1) The 3T model overestimated the transpiration rate of the citrus tree, while the 5P-3T model underestimated it. The estimated values of the 5P-3T model have a good correlation with the measured values of the packaged stem sap flow gauge method, with a determination coefficient (R2) of 0.72 and root mean square error (RMSE) of 0.35 mm/d. (2) In this model, the plant transpiration transfer coefficient (hat) can evaluate the water shortage of plants, where the value of hat increased with the aggravation of plant water stress. (3) The citrus trees have lower transpiration rates under water stress, ranging from 0.06 to 0.12 mm/h in the daytime (from 8-10 May 2021). The model used in this study only needs the input of temperature information and net radiation, and would not depend on aerodynamic resistance. The method in this paper can realize the non-contact and non-invasive measurement of crop transpiration, and it provides a feasible way to use a portable thermal imager to accurately obtain the temperature for estimating plant canopy transpiration rate.

High aerosol loading decreases the transpiration of poplars both in the day- and night-time

Aerosols alter plant photosynthesis and ecosystem carbon uptake through radiative effects. These effects inevitably change plant transpiration and ecosystem water use as CO2 and water exchange couple through leaf stomatal conductance. However, because of lacking field observations, we know poorly about how elevated aerosols could affect plant transpiration, which greatly hinders our confidence in projecting aerosol's climate impacts. In this study, taking the advantage of aerosol loading in northern China fluctuated periodically over a wide range, we conducted five year-site observations of the stem sap flow of poplar saplings (Populus euramericana Neva.), and simultaneously monitored environmental factors such as PM2.5 concentration, total and diffuse radiation, air temperature, humidity, and soil water content. These observations enabled us to comprehensively explore how aerosols affect the daily dynamics of plant canopy transpiration in the field. We found that high aerosol loading significantly decreased the sap flow density of poplars both in the day- and night-time, indicating that aerosols decreased canopy transpiration. Furthermore, during the day-time, a reduction in total solar radiation and moisture demand (vapor pressure deficit, VPD) dominated the decrease of sap flow density, but an increase in diffuse radiation had an insignificant impact. In the night-time, VPD significantly decreased under high aerosol loading conditions, thereby reducing nocturnal sap flow density. Our in-situ observations revealed that different from the positive response of canopy photosynthesis associated with the diffuse fertilization effect, aerosols inhibit canopy transpiration mainly because of the declined VPD. Our findings highlighted that plant carbon and water fluxes are governed by different meteorological factors under elevated aerosol.

Antibacterial activity of Betadine (Jatropha multifida L.) stem extract on Pseudomonas aeruginosa growth in vitro

Background: Today, people use plants to treat various types of diseases and improve human health. One of the medicinal plants is the Betadine plant (Jatropha multifida L.). Betadine plants have many functions, especially the sap, leaves, fruit and seeds. The compound contents in Betadine stem sap, which is efficacious as an antimicrobial, are saponins, tannins, flavonoids and labaditin. One of the bacteria that cause infection is Pseudomonas aeruginosa. These bacteria can cause opportunistic and nosocomial infections. Methods: This study was a true experimental laboratory with a post-test only control group design. This study used Betadine stem sap extract with concentrations of 25%, 50%, 75%, 100%, gentamicin cream 10% as positive control, and dimethyl sulfoxide (DMSO) solution as negative control. This study used the Kirby-Bauer diffusion method and the bacterium Pseudomonas aeruginosa was grown on nutrient agar media, then incubated for 24 hours and calculated using calipers. Research data were analyzed using one-way ANOVA test. Results: The highest inhibition zone was group 50% (12.725 ± 0.2500 mm) while the lowest inhibition zone was group 100% (8.675 ± 0.5620 mm). Conclusions: Betadine stem extract had antibacterial activity in inhibiting the growth of Pseudomonas aeruginosa bacteria, with the 50% concentration being the most effective in inhibiting the growth of Pseudomonas aeruginosa bacteria.

Water Storage and Use by Platycladus orientalis under Different Rainfall Conditions in the Rocky Mountainous Area of Northern China

Tree water transport and utilization are essential for maintaining ecosystem stability in seasonally arid areas. However, it is not clear how Platycladus orientalis absorbs, consumes via transpiration, and stores water under varying precipitation conditions. Therefore, this study used stem sap flow thermal dissipation probes and hydrogen and oxygen isotope tracing technology to observe different water control treatments in a P. orientalis plantation. We found that the average daily sap flow of P. orientalis under different water control treatments had the following order: no rainfall (NR) < half rainfall (HR) < double rainfall (DR) < natural rainfall (AR). The percentage of nocturnal sap flow was as follows: AR (13.34%) < NR (19.62%) < DR (20.84%) < HR (30.90%). The percentage of water storage was NR (4.13%) < AR (4.49%) < DR (6.75%) < HR (9.29%). The sap flow of P. orientalis was primarily affected by vapor pressure deficit and solar radiation, with a degree of influence of DR < NR < HR < AR. The response of P. orientalis sap flow to environmental factors differed due to the soil changes in relative extractable water (REW) before and after precipitation. During high REW conditions, environmental factors have a higher impact on sap flow. The source of water absorbed changed regularly with the precipitation gradient. When soil water content increased, the water source used by P. orientalis gradually changed to shallow soil. Compared to before and after precipitation, there was no significant change except for NR. P. orientalis could regularly adjust the activities of transpiration water consumption, water storage, and absorption. This adaptive property is conducive to survival through extreme drought stress.