Plant Physiological Parameters Research Articles

Treated municipal wastewater as option to the use of fresh water for the cultivation of valuable pastoral species Buffel grass (Cenchrus ciliaris L.)

AbstractThe increasing aridity exacerbated by climatic changes is leading to loss of perennial herbaceous plants Cenchrus ciliaris, an apomictic, polyploid grass used as forage in hot and dry areas, and is currently under threat for the increased scarcity of water. In this study, treated municipal wastewater (TWW) was used to irrigate two ploidy levels of C. ciliaris for two consecutive years. The objectives were (1) to assess the possibility of using unconventional water for watering C. ciliaris and (2) to identify at what extent TWW irrigation affected growth and nutritive properties of C. ciliaris that differed for polyploidy level. TWW irrigation positively affected growth and physiological plant parameters. In leaves of TWW watered C. ciliaris, the concentration of Nt, P and K significantly increased. The tetraploid C. ciliaris showed a better growth and quality than the hexaploid ones, appearing the most suitable cultivar to be irrigated with TWW for feed uses. In short, TWW can be strategically used for irrigating forage species with the double output of ameliorating soil properties, recovering degraded area and improving the nutritive values of fodder species contributing to the promotion of a green and sustainable circular economy, more in climatically under pressure developing countries.

Sounds emitted by plants under stress are airborne and informative

Stressed plants show altered phenotypes, including changes in color, smell, and shape. Yet, airborne sounds emitted by stressed plants have not been investigated before. Here we show that stressed plants emit airborne sounds that can be recorded from a distance and classified. We recorded ultrasonic sounds emitted by tomato and tobacco plants inside an acoustic chamber, and in a greenhouse, while monitoring the plant's physiological parameters. We developed machine learning models that succeeded in identifying the condition of the plants, including dehydration level and injury, based solely on the emitted sounds. These informative sounds may also be detectable by other organisms. This work opens avenues for understanding plants and their interactions with the environment and may have significant impact on agriculture.

Vallisneria natans decreased CH4 fluxes in wetlands: Interactions among plant physiological status, nutrients and epiphytic bacterial community

Submerged macrophytes provide niches for epiphytic microbes (including aerobic methanotrophs) growth. However, little is known about the impacts of submerged macrophytes growth status and nutrients loadings on methanotroph community and methane release in wetlands. In the present study, methane fluxes, bacterial and methanotroph community in epiphytic biofilm, and environmental parameters were investigated during Vallisneria natans senescence in wetlands under low (VnL) and high (VnH) nutrients for seven weeks. Relative conductivity and concentration of H2O2, total chlorophyll and malondialdehyde were higher in leaves of V. natans in VnH than VnL at the same sampling time. Nutrients loading increased methane fluxes in treatments with or without (Control) macrophytes, while healthy V. natans plants reduced the methane flux and nutrients concentration in water columns. CH4 fluxes were positively correlated to temperature and COD (p < 0.05). Methane oxidation rates were 3.04–31.68 μmol methane mg−1 fresh weight of V. natans leaves - epiphytic biofilm within 1 h. Proteobacteria, Cyanobacteria, Bacteroidetes, Verrucomicrobia, Planctomycetes, Actinobacteria and Acidobacteria were dominant phylum in all epiphytic biofilms. The mean abundances of pmoA/16S rRNA were higher in VnL than VnH. According to Illumina sequencing results of pmoA gene, γ-proteobacteria and α-proteobacteria were the dominant methanotroph class in epiphytic biofilm from VnH and VnL, respectively. Among seven detected methanotrophic genera, Methylomonas was significantly higher in VnH than VnL. Network analysis revealed that there were much closer relationships between the environmental parameters and epiphytic bacterial community in VnH than in VnL. COD and MDA were negatively correlated with Methyloglobulus, Methylosarcina, Methylobacter and Methylocystis, but positively correlated with Methylomonas and Methylosinus. This study highlights that methanotrophs in epiphytic biofilm play important roles in methane-oxidizing, which can be affected by plant physiological status and environmental parameters.

Microclimate effects and influential mechanisms of four urban tree species underneath the canopy in hot and humid areas

Purpose: Urban trees play a key role in ameliorating extreme urban climates in cities. At the micro-level, it is crucial to investigate the variations in microclimates affected by the canopies of different tree species. The significance of this research is to provide scientific evidence for the selection of tree species in urban planning that can improve the local microclimate. This study examines the factors of microclimate (air temperature, relative humidity, wind environment, and solar radiation) underneath the canopy of four different evergreen tree species in hot and humid areas. Furthermore, the correlation between the physiological characteristics of these tree species and microclimate was statistically analyzed using data on the physiological parameters of the trees and microclimate factors.Methods: In this study, four tree species were selected for field measurements: Ficus microcarpa L. f., Ficus virens Aiton, Bauhinia x blakeana Dunn, and Cinnamomum camphora (L.) Presl. We used the HOBE (H21-0024, onset) to measure three climatic parameters (Temperature, Relative Humidity, and Instantaneous Wind Speed), and the Li-6400 Portable Photosynthesis System to measure five plant physiological parameters: Stomatal Conductance (Gs), Leaf Temperature (Tleaf), Leaf Surface Relative Humidity (RHsfc), Photosynthetically Active Radiation (PAR), and Leaf-level Vapor Pressure Deficit (Vpdl). The observations were conducted during winter (January 16 - January 22) and summer (August 7 - August 22). The investigation periods were 9:00–11:00, 12:00–14:00, and 16:00–18:00, and data were recorded at 15-min intervals. The observational data obtained were analyzed using statistical methods, including one-way analysis of variance, Pearson correlation coefficient, and multiple regression analysis.Results: The results of this study indicated that the four tree species being measured had different effects on the microclimate at the sites in both the winter and summer seasons. During the 7-day observation in the summer, the cooling effect of the four tree species was significant. The relative humidity underneath the canopies was 3%–11% higher than that of weather stations. The instantaneous wind speed in the afternoon was relatively higher than at other times. The solar radiation intensity was dramatically reduced by 85%–95%. During the 7-day observation in the winter, the trees had a warming effect in the morning. The relative humidity underneath the canopies was 10%–20% higher than that of the weather stations. The areas underneath the canopies were windless in the afternoon. The solar radiation intensity was reduced by 78%–95%. Ficus microcarpa was found to be one of the most effective tree species for increasing the relative humidity and reducing solar radiation intensity in hot and humid areas. Additionally, the highest instantaneous wind speed was observed in the areas underneath the canopies of F. virens and C. camphora. Statistical tests revealed that the air temperature and the instantaneous wind were extremely significantly correlated with Tleaf and RHsfc.Conclusion: The four urban tree species studied had varying degrees of effect on air temperature, relative humidity, wind speed, and reducing solar radiation intensity in the areas underneath their canopies. Furthermore, these trees demonstrated varying abilities to improve microclimate conditions in different seasons. The four trees had a cooling effect in the summer. The instantaneous wind speed was calm in the afternoons during the winter in contrast to being relatively high speed in the afternoons during the summer. This characteristic is beneficial to warmth in winter and coolness in summer. In terms of the internal influence mechanisms, the results of the analysis indicated that microclimate factors were significantly correlated with the physiological parameters of the trees. Tleaf, RHsfc, and Vpdl were significant physiological parameters and had different contribution rates to microclimate factors.

Evaluation of Selenium Nanoparticles in Inducing Disease Resistance against Spot Blotch Disease and Promoting Growth in Wheat under Biotic Stress.

In the present study, SeNPs were synthesized using Melia azedarach leaf extracts and investigated for growth promotion in wheat under the biotic stress of spot blotch disease. The phytosynthesized SeNPs were characterized using UV-visible spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and Fourier-transformed infrared spectroscopy (FTIR). The in vitro efficacy of different concentrations of phytosynthesized SeNPs (i.e., 100 μg/mL, 150 μg/mL, 200 μg/mL, 250 μg/mL, and 300 μg/mL) was evaluated using the well diffusion method, which reported that 300 μg/mL showed maximum fungus growth inhibition. For in vivo study, different concentrations (10, 20, 30, and 40 mg/L) of SeNPs were applied exogenously to evaluate the morphological, physiological, and biochemical parameters under control conditions and determine when infection was induced. Among all treatments, 30 mg/L of SeNPs performed well and increased the plant height by 2.34% compared to the control and 30.7% more than fungus-inoculated wheat. Similarly, fresh plant weight and dry weight increased by 17.35% and 13.43% over the control and 20.34% and 52.48% over the fungus-treated wheat, respectively. In leaf surface area and root length, our findings were 50.11% and 10.37% higher than the control and 40% and 71% higher than diseased wheat, respectively. Plant physiological parameters i.e., chlorophyll a, chlorophyll b, and total chlorophyll content, were increased 14, 133, and 16.1 times over the control and 157, 253, and 42 times over the pathogen-inoculated wheat, respectively. Our findings regarding carotenoid content, relative water content, and the membrane stability index were 29-, 49-, and 81-fold higher than the control and 187-, 63-, and 48-fold higher than the negative control, respectively. In the case of plant biochemical parameters, proline, sugar, flavonoids, and phenolic contents were recorded at 6, 287, 11, and 34 times higher than the control and 32, 107, 33, and 4 times more than fungus-inoculated wheat, respectively. This study is considered the first biocompatible approach to evaluate the potential of green-synthesized SeNPs as growth-promoting substances in wheat under the spot blotch stress and effective management strategy to inhibit fungal growth.

The Response of Purslane (Portulaca oleracea) to Soil-Added Pb: Is It Suitable as a Potential Phytoremediation Species?

Soils with high lead (Pb) levels can be decontaminated with the use of tolerant plants. Their effectiveness may be increased with added soil N due to boosted plant vigor, but such an agronomic practice has not been widely reported so far. In this work, purslane (Portulaca oleracea) was tested in a pot experiment as a potential phytoremediation species using soil spiked with Pb at doses of 0, 150, 300, 600, and 900 mg kg-1 (referred to as Pb(0), Pb(150), Pb(300), Pb(600), and Pb(900), respectively) with added N (referred to as N(1); at 300 kg N ha-1) and without added N (N(0)). We found that added Pb did not cause any adverse effects on plant growth (height, and aerial and root dry biomass) and physiological parameters, which were boosted with added N. Lead plant concentration and uptake significantly increased with added N, a finding that confirms our hypothesis. The number of necessary harvests of purslane in order to reduce soil Pb to half its initial concentration was also calculated and found to decrease with added N, being 131 at Pb(900)N(1). Although results indicate the potential of purslane as a phytoremediation species, further research is needed under real field conditions.

Antifungal activity of eco-safe nanoemulsions based on Nigella sativa oil against Penicillium verrucosum infecting maize seeds: Biochemical and physiological traits.

The main goals of the present investigation were to develop O/W nanoemulsion fungicides based on cold-pressed Nigella sativa (black seed) oil to prevent Penicillium verrucosum infection of maize seeds and to test their antifungal activity against this fungus. Additionally, the effect of these nanoemulsions on plant physiological parameters was also investigated. Two nonionic surfactants namely Tween 20 and Tween 80 were used as emulsifying agents in these formulations. The effect of sonication time and surfactant type on the mean droplet size, polydispersity index (PDI), and zeta potential of the nanoemulsions were determined by dynamic light scattering (DLS). Results indicated that both sonication time and emulsifier type had pronounced effects on the stability of O/W nanoemulsions with a small particle size range (168.6-345.3 nm), acceptable PDI (0.181-0.353), and high zeta potential (-27.24 to -48.82 mV). Tween 20 showed superior stability compared to Tween 80 nanoemulsions. The in vitro results showed that complete inhibition of P. verrucosum-growth was obtained by 10_T80 and 10_T20 nanoemulsions at 100% concentration. All nanoemulsions had increment effects on maize seed germination by 101% in the case of 10_T20 and 10_T80 compared to untreated seeds or the chemical fungicide treatment. Nanoemulsions (10_T20 and 10_T80) were able to stimulate root and shoot length as compared to the fungicide treatment. Seed treatment with 10_T80 nanoemulsion showed the highest AI and protease activity by 75 and 70%, respectively, as compared to the infected control. The produced nanoemulsions might provide an effective protectant coating layer for the stored maize seeds.

A systematic review on the strategies of reducing asphalt pavement temperature

Under the action of repeated load of vehicles, asphalt pavement tends to suffer rutting and other failures at high temperatures, which shortens the service life of the pavement. Meanwhile, asphalt pavement aggravates the urban heat island (UHI) effect, reducing the livability of the city. Research shows that lower road temperatures can mitigate the UHI effect. For this reason, researchers have launched lots of studies to cool asphalt pavement under high temperatures, such as reflective pavement and phase change pavement, etc. Although these technologies are effective at reducing the temperature of asphalt pavement, there are still some limitations. This paper mainly discusses the latest development of asphalt pavement temperature reduction strategies, classifies them according to different action mechanisms, and discusses the advantages and limitations of each strategy in detail. Suggestions for future research are given to address the limitations of each strategy, such as passive radiation technology can provide new ideas for reflective pavement, planting trees should consider plant physiological parameters and spatial distribution of planting, and phase change materials can be encapsulated by high thermal conductivity materials, etc. This study can provide a guidance for further development of asphalt pavement cooling technologies.

Effect of Elevated CO2 on the Growth, Physiological Traits and Biological Yield of Three Genotypes of Wheat (Triticum aestivum L.)

Because of economical relevance of wheat being a staple crop, it is important to understand how this crop will respond to the foreseen increase in atmospheric CO2 conc. An experiment was conducted to know about the physiological and growth pattern of three genotypes PBW-373, PBW-343, PBW-502 of wheat (Triticum aestivum L.) under elevated CO2 condition. Two chambers one with increased CO2 and one with ambient CO2 were employed. Crop was cultivated within the chamber under ambient (400 ppm) and enhanced CO2 (800 ppm) conditions, from seedling to maturity. Compared to ambient CO2 , crop produced more biomass. The impact of EC on plant growth, reproductive structure, productivity and physiological parameters (photosynthetic rate, transpiration, stomatal conductance, morphology, leaf area and biomass) etc. were examined. The outcomes weren’t one way. For one plant growth cycle, all the parameters were recorded. Photosynthetic rate, transpiration rate, stomatal conductance, and biomass all experienced significant increases among two genotypes out of three. Overall performance of PBW-343, PBW-373 was determined to be good in view of test weight under high CO2 conditions. Genotypic variation was also documented. Both genotypes are known to be tolerant of high CO2 conditions. Overall, it can be said that EC promotes plant growth and biomass, although further research is needed to determine how EC affects flowering. Increases in shoot length, root length, and the number of tillers in terms of their size and weight were caused by the high CO2 concentration. The economic yield of wheat per plant significantly increases when exposed to high CO2 . In this work, we investigated the impact of current and projected CO2 concentration on wheat crop growth, biomass, and yield.

Agro-physiological and soil microbial responses to desalinated seawater irrigation in two crops

Irrigation with desalinated seawater (DSW) is a potential solution for addressing water scarcity in semiarid regions across the globe. However, this strategy may compromise the health of agricultural ecosystems due to the high content of phytotoxic elements (mainly boron, B) in this water. Here, a three-year experiment was carried to evaluate the response of the soil’s physicochemical and microbiological properties, and plant physiology, to three irrigation water treatments (DSW; fresh water, FW; and their blend (1:1), BW) in the presence or not of organic amendments. Lemon trees (Citrus limon (L.) Burm. fil. cv. Eureka), with a higher sensitivity to B toxicity, and apricot trees (Prunus armeniaca L. cv. ‘Búlida’), with a lower one, were used as model plants. Lemon trees irrigated with BW and DSW showed a decline in net photosynthesis and stomatal conductance, and an accumulation of B in leaves that exceeded the toxicity threshold. These effects were stronger in amended soils. In soils cultivated with lemon trees, DSW irrigation increased the water-soluble nitrogen content, the urease activity, and the activity and biomass of the microbial community, and shifted the microbial community structure as compared with the other water treatments. The soil microbial community responses were controlled by the addition of organic amendments. The irrigation of apricots with DSW did not negatively impact plant physiological parameters but increased the soil microbial biomass, as in the case of the lemon tree-soil system. These results suggest that DSW irrigation increases soil microbial biomass in both crop-soil systems but harms the physiological status of the most sensitive crop. Our findings provide an initial approach to evaluate the response of the plant-soil system to DSW.

Plant Growth Monitoring: Design, Fabrication, and Feasibility Assessment of Wearable Sensors Based on Fiber Bragg Gratings

Global climate change and exponential population growth pose a challenge to agricultural outputs. In this scenario, novel techniques have been proposed to improve plant growth and increase crop yields. Wearable sensors are emerging as promising tools for the non-invasive monitoring of plant physiological and microclimate parameters. Features of plant wearables, such as easy anchorage to different organs, compliance with natural surfaces, high flexibility, and biocompatibility, allow for the detection of growth without impacting the plant functions. This work proposed two wearable sensors based on fiber Bragg gratings (FBGs) within silicone matrices. The use of FBGs is motivated by their high sensitivity, multiplexing capacities, and chemical inertia. Firstly, we focused on the design and the fabrication of two plant wearables with different matrix shapes tailored to specific plant organs (i.e., tobacco stem and melon fruit). Then, we described the sensors' metrological properties to investigate the sensitivity to strain and the influence of environmental factors, such as temperature and humidity, on the sensors' performance. Finally, we performed experimental tests to preliminary assess the capability of the proposed sensors to monitor dimensional changes of plants in both laboratory and open field settings. The promising results will foster key actions to improve the use of this innovative technology in smart agriculture applications for increasing crop products quality, agricultural efficiency, and profits.

Ameliorative effects of foliar potassium nitrate on the growth, physiological, and stomatal properties of lettuce plants under salinity stress

The restorative effects of foliar potassium nitrate spraying on morphological, physiological, and stomata properties of salt-affected lettuce (Lactuca sativa L.) cv. Yedikule plants were investigated. Lettuce seedlings grown under saline irrigation water constituted by NaCl levels with 50, 100, 150, and 200 mM were sprayed with foliar KNO3 at 500 mg L−1 after 30-day-old plants. Salinity stress adversely influenced plant growth and physiological parameters. Fresh plant biomass, leaf area per plant, and leaf number were limited at 100 mM NaCl and above. Leaf temperature, chlorophyll content, dry matter, turgor loss, and electrolyte leakage were enhanced under saline conditions; however, salinity diminished leaf relative water content. Foliar KNO3 spraying improved the physiologic and stomata traits of salt-affected lettuce plants rather than plant growth. The electrolyte leakage was increased by increasing salinity and KNO3 spraying, whereas the relative injury was lower in the plants treated with foliar KNO3. An increase in stomata density was detected up to 100 mM NaCl, while stomata length and width were gradually decreased. Salinity and foliar KNO3 resulted in more frequent stomata number up to 100 mM NaCl, but it was surprisingly reduced at higher NaCl levels. Lettuce plants could grow up with irrigation water salinity of 100 mM and foliar KNO3 with 500 mg L−1 could regulate the adverse effects of salinity on the physiological characteristics up to 100 mM NaCl.

Функциональная диагностика баланса элементов питания в растениях и урожайность зерна озимого тритикале при использовании водорастворимых удобрений

The method of functional diagnostics made it possible to identify the possibility of correcting the imbalance of plant nutrients and increasing the productivity of winter triticale when using water-soluble fertilizers that contain macro- and microelements, as well as biologically active substances and humic acids and help winter triticale plants maintain a homeostatic state and increase the stability and yield of grain culture, which on average for 3 years amounted to 4.25 t/ha and 4.26 t/ha, which is 38.90 and 39.0% higher than the control variant and 38.37-38.47% of biological yield data against the organomineral background. Keywords: BALANCE OF NUTRIENTS, METHOD OF FUNCTIONAL DIAGNOSTICS, PHYSIOLOGICAL PARAMETERS OF PLANTS, BIOLOGICAL PRODUCTIVITY

Assessment of Cyanobacteria and Tryptophan role in the Alleviation of the Toxic Action of Brominal Herbicide on Wheat Plants

Cyanobacteria like Arthrospira platensis and Nostoc muscorum are known to be beneficial for plant development. They can improve plant growth, yield, proximate content (protein and carbohydrate), and stimulate plant tolerance to abiotic stresses like herbicides. In the present study, the impacts of brominal herbicide (Bh) alone or in combination with natural cyanobacterial or synthetic tryptophan treatments were investigated on the morphological and physiological parameters of wheat plants. The Bh treatment caused a reduction in all the estimated morphological and physiological parameters of the plants. The combination of Bh and cyanobacterial or tryptophan treatments could significantly increase the plant length, fresh and dry weights, and yield parameters (spike length, spike weight, number of spikes per plant, number of grains per spike, weight of 1000 grains, and productivity). In addition, pigments, carbohydrates, and protein content was also reduced in response to the Bh treatment, while the antioxidant enzyme activity and lipid peroxidation increased. Priming wheat grains in cyanobacterial aqueous extract and tryptophan before cultivation reversed the toxic effects of Bh application, amplified extra antioxidant ability, and decreased the lipid peroxidation of the plants. Finally, the combination of cyanobacterial and tryptophan as treatments for priming wheat grains before being sown in the soil should help to strengthen the defense systems of the wheat plant to tolerate the adverse effects of species-specific Bh upon application.

Effect of micro–spray on plant growth and chlorophyll fluorescence parameter of tomato under high temperature condition in a greenhouse

Micro–spray is usually used to improve plant growth environment to avoid growth inhibiting and yield decreasing due to the high temperature inside the greenhouses in summer. To investigate the effect of micro–spray on plant growth and physiological properties, a combined irrigation method of micro–spray and drip irrigation (MSDI) was applied to tomato plants growing in a Venlo–type greenhouse for two seasons. The plant growth and physiological parameters of tomatoes grown under MSDI were compared with them under drip irrigation (DI). The running time of micro–spray was set based on the timing of high air temperature (Ta) appeared. The micro–spray was opened (7.5 L/h for each nozzle) for 1 min for each time point at 9:00, 10:00, 11:00, 12:00, 13:00 and 14:00 when the Ta was higher than 30 °C. The MSDI had a positive effect on plants growth (18% increased in stem diameter compared to DI) and the leaf temperature (Tl) decreased around 3–6 °C when the micro–spray was operated, and the cooling effect can be sustained for 10–30 min. Water use efficiency (WUE) under MSDI was similar to it under DI by comparing yield and total water consumption of tomato plants, and the total soluble solids (TSS) of tomato under two irrigation methods were similar (5.4% under DI and 5.5% under MSDI) during 2021.The results shown that the photosynthetically active radiation (PAR) and Ta were represented a negative correlation with chlorophyll fluorescence parameter (the effective quantum yield of PSII, ФPSII). The ФPSII value of tomato under MSDI was higher than it under DI during the micro–spray operating period, and it was more stable during the high Ta period. The improvement rate of ФPSII at different intensity of PAR (at 9:30, 10:30, 11:30, 12:30, 13:30 and 14:30) was varied, and it had a unified decline at 12:30 at the highest Tl during two seasons. Short time (1minute) micro–spray application did not have a remarkable effect on the adjusting of the damage caused by heat stress once temperature over 35 °C. Applying MSDI for tomato plants grown in greenhouse is recommended to reduce the severe effect on plant growth and physiology by high temperature. In addition, the result of this study provides a scientific guide for the development of intellectualization irrigation systems.

Screening, and Optimization of Fermentation Medium to Produce Secondary Metabolites from Bacillus amyloliquefaciens, for the Biocontrol of Early Leaf Spot Disease, and Growth Promoting Effects on Peanut (Arachis hypogaea L.).

A novel Bacillus amyloliquefaciens BAM strain, with novel fermentation nutrient mediums and compositions, could produce potent antifungal secondary metabolites, as the existing strains face resistance from fungus pathogens. In the current study, we introduced two novel nutrient mediums for the fermentation process, semolina and peanut root extract, as carbon and nitrogen sources in order to maximize the antifungal effects of B. amyloliquefaciens against Cercaspora arachidichola to control early leaf spot disease in peanuts. Based on a single-factor test and the central composite design of response surface methodology, the optimum fermentation medium for Bacillus amyloliquefaciens antagonistic substance was determined, containing 15 gm/L of semolina flour, 12.5 gm/L of beef extract, and 0.5 gm/L of magnesium sulfate, which inhibited the fungal growth by 91%. In vitro, antagonistic activity showed that the fermentation broth of B. amyloliquefaciens BAM with the optimized medium formulation had an inhibition rate of (92.62 ± 2.07)% on the growth of C. arachidichola. Disease control effects in pot experiments show that the pre-infection spray of B.&amp;nbsp;amyloliquefaciens BAM broth had significant efficiency of (92.00 ± 3.79)% in comparison to post-infection spray. B. amyloliquefaciens BAM broth significantly promoted peanut plant growth and physiological parameters and reduced the biotic stress of C. archidechola. Studies revealed that B. amyloliquefaciens BAM with a novel fermentation formulation could be an ideal biocontrol and biofertilizer agent and help in early disease management of early leaf spots in peanuts.

Photosynthesis, yielding and quality of pea seeds depending on the row spacing and sowing density

Pea is one of the most important legumes grown in the world. The seeds are used for food production and animal feed. The problem with its cultivation is the low yield and sensitivity to the course of the weather. The important factor is to determine the optimal sowing rate and row spacing, especially for new cultivars of pea. Therefore, research was undertaken to assess the effect of row spacing and sowing density on selected physiological parameters, yielding, and structural elements of peas cv. ‘Batuta’ in Poland. The results of the research showed that the row spacing and sowing density determine the values of plant physiological parameters, yield of pea seeds and protein content. The increase in plant density in the canopy caused a decrease in the measured parameters of chlorophyll fluorescence, such as maximum quantum yield of photosystem II ( Fv/Fm) and maximum quantum yield of primary photochemistry ( Fv/F0) and performance index ( PI). The leaf area index ( LAI) was lower with a wider row spacing. Row spacing and plant density determined yield of pea seeds, number of pods and seeds per plant and weight of seeds per plant. Wider row spacing resulted in a decrease in the protein content in seeds, while an increase in sowing density from 70 to 110 m 2 caused its increase. The course of the weather during the vegetation period of plants significantly influenced the obtained results.

Early Detection of Fusarium oxysporum Infection in Processing Tomatoes (Solanum lycopersicum) and Pathogen-Soil Interactions Using a Low-Cost Portable Electronic Nose and Machine Learning Modeling.

The early detection of pathogen infections in plants has become an important aspect of integrated disease management. Although previous research demonstrated the idea of applying digital technologies to monitor and predict plant health status, there is no effective system for detecting pathogen infection before symptomatology appears. This paper presents the use of a low-cost and portable electronic nose coupled with machine learning (ML) models for early disease detection. Several artificial neural network models were developed to predict plant physiological data and classify processing tomato plants and soil samples according to different levels of pathogen inoculum by using e-nose outputs as inputs, plant physiological data, and the level of infection as targets. Results showed that the pattern recognition models based on different infection levels had an overall accuracy of 94.4-96.8% for tomato plants and between 94.81% and 96.22% for soil samples. For the prediction of plant physiological parameters (photosynthesis, stomatal conductance, and transpiration) using regression models or tomato plants, the overall correlation coefficient was 0.97-0.99, with very significant slope values in the range 0.97-1. The performance of all models shows no signs of under or overfitting. It is hence proven accurate and valid to use the electronic nose coupled with ML modeling for effective early disease detection of processing tomatoes and could also be further implemented to monitor other abiotic and biotic stressors.

Interactive salinity and water stress severely reduced the growth, stress tolerance, and physiological responses of guava (Psidium Guajava L.)

Salinity and water stress are serious environmental issues that reduced crop production worldwide. The current research was initiated (2012) in the wirehouse of the Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan to investigate the growth, stress tolerance, and physiological responses of guava to salinity and water shortage. Guava was grown for one year in pots containing soil with Eight treatments (control, 10 dS m−1, 20 dS m−1, 40 dS m−1, control + water stress (WS), 10 dS m−1 + WS, 20 dS m−1 + WS, 40 dS m−1 + WS) in a completely randomized design. The results indicated that plant growth, stress tolerance, and physiological parameters declined at higher salinity and water stress and could not survive at 40 dS m−1. The 20 dS m−1 + WS caused a > 70% decline in dry weights of shoot and root regarding control. Similarly, the highest decrease in stress tolerance was noticed in 20 dS m−1 + WS followed by the 20 dS m−1 treatment than control. Our findings validated that guava can be cultivated on soils having salinity ≤ 10 dS m−1 but it could not be cultivated on soils having salinity ≥ 20 dS m−1 with limited water supply.

Agricultural Crops Grown in Laboratory Conditions on Chernevaya Taiga Soil Demonstrate Unique Composition of the Rhizosphere Microbiota.

Chernevaya taiga in West Siberia is a unique environment, with gigantism of grasses and shrubs. Exceptionally high productivity of plants is determined by the synergistic interaction of various factors, with a special role belonging to microorganisms colonizing the plant roots. This research explored whether agricultural plants can recruit specific microorganisms from within virgin Chernevaya Umbrisol and thus increase their productivity. Radish and wheat plants were grown on the Umbrisol (T1) and control Retisol of Scotch pine forest stand (T3) soils in the phytotron, and then a bacterial community analysis of the rhizosphere was performed using high-throughput sequencing of the 16S rRNA genes. In laboratory experiments, the plant physiological parameters were significantly higher when growing on the Umbrisol as compared to the Retisol. Bacterial diversity in T1 soil was considerably higher than in the control sample, and the principal coordinate analysis demonstrated apparent differences in the bacterial communities associated with the plants. Agricultural plants growing in the T1 soil form specific prokaryotic communities, with dominant genera Chthoniobacter, Pseudomonas, Burkholderia, and Massilia. These communities also include less abundant but essential for plant growth nitrifiers Cand. Nitrosocosmius and Nitrospira, and representatives of Proteobacteria, Bacilli, and Actinobacteria, known to be gibberellin-producers.