Bloom Stage Research Articles

Earlier sea-ice melt extends the oligotrophic summer period in the Barents Sea with low algal biomass and associated low vertical flux

The decrease in Arctic sea-ice extent and thickness as a result of global warming will impact the timing, duration, magnitude and composition of phytoplankton production with cascading effects on Arctic marine food-webs and biogeochemical cycles. Here, we elucidate the environmental drivers shaping the composition, abundance, biomass, trophic state and vertical flux of protists (unicellular eukaryotes), including phytoplankton, in the Barents Sea in late August 2018 and 2019. The two years were characterized by contrasting sea-ice conditions. In August 2018, the sea-ice edge had retreated well beyond the shelf break into the Nansen Basin (>82°N), while in 2019, extensive areas of the northwestern Barents Sea shelf (>79°N) were still ice-covered. These contrasting sea-ice conditions resulted in marked interannual differences in the pelagic protist community structure in this area. In August 2018, the protist community was in a post-bloom stage of seasonal succession characterized by oligotrophic surface waters and dominance of small-sized phytoplankton and heterotrophic protists (predominantly flagellates and ciliates) at most stations. In 2019, a higher contribution of autotrophs and large-celled phytoplankton, particularly diatoms, to total protist biomass compared to 2018 was reflected in higher chlorophyll a concentrations and suggested that the protist community was still in a late bloom stage at some stations. It is noteworthy that particularly diatoms contributed a considerably higher proportion to the protist biomass at the ice-covered stations in both years compared to the open-water stations. This pattern was also evident in the higher vertical protist biomass flux in 2019, dominated by dinoflagellates and diatoms, compared to 2018. Our results suggest that the predicted transition toward an ice-free Barents Sea will lengthen the oligotrophic summer period with low algal biomass and associated low vertical flux.

Viruses may facilitate the cyanobacterial blooming during summer bloom succession in Xiangxi Bay of Three Gorges Reservoir, China.

The occurrence of cyanobacterial blooms in summer are frequently accompanied by the succession of phytoplankton communities in freshwater. However, little is known regarding the roles of viruses in the succession, such as in huge reservoirs. Here, we investigated the viral infection characteristics of phytoplankton and bacterioplankton during the summer bloom succession in Xiangxi Bay of Three Gorges Reservoir, China. The results indicated that three distinct bloom stages and two successions were observed. From cyanobacteria and diatom codominance to cyanobacteria dominance, the first succession involved different phyla and led to a Microcystis bloom. From Microcystis dominance to Microcystis and Anabaena codominance, the second succession was different Cyanophyta genera and resulted in the persistence of cyanobacterial bloom. The structural equation model (SEM) showed that the virus had positive influence on the phytoplankton community. Through the Spearman's correlation and redundancy analysis (RDA), we speculated that both the increase of viral lysis in the eukaryotic community and the increase of lysogeny in cyanobacteria may contributed to the first succession and Microcystis blooms. In addition, the nutrients supplied by the lysis of bacterioplankton might benefit the second succession of different cyanobacterial genera and sustain the dominance of cyanobacteria. Based on hierarchical partitioning method, the viral variables still have a marked effect on the dynamics of phytoplankton community, although the environmental attributes were the major factors. Our findings suggested that viruses played multiple potential roles in summer bloom succession and may help the blooms success of cyanobacteria in Xiangxi Bay. Under the background of increasingly serious cyanobacterial blooms worldwide, our study may have great ecological and environmental significance for understanding the population succession in phytoplankton and controlling the cyanobacterial blooms.

Assessing the impact of phyllosphere microbiota on dynamics of in-silo fermentation of Italian ryegrass harvested at heading and blooming stages.

The present study aimed to investigate the relationship between the phyllosphere microbiota of Italian ryegrass (Lolium multiflorum Lam.) harvested at heading (H) [> 50% earing rate or 216 g kg-1 fresh weight (FW)] and blooming (B) (> 50% bloom or 254 g kg-1 FW) stages and in-silo fermentation products, and the composition, abundance, diversity and activity of bacterial community. In total, 72 (4 treatments × 6 ensiling durations × 3 replicates) laboratory scale (400 g) silages of Italian ryegrass were prepared: (i) irradiated heading stage silages (IRH) (n=36) were inoculated with phyllosphere microbiota inoculum (2mL) eluted from fresh Italian ryegrass at either heading (IH) (n=18) or blooming (IB) (n=18) stages; (ii) irradiated blooming stage silages (IRB) (n=36) were inoculated with either IH (n=18) or IB (n=18). Triplicate silos of each treatment were analyzed after 1, 3, 7, 15, 30 and 60 days of ensiling. In fresh forage, Enterobacter, Exiguobacterium and Pantoea were the three major genera at heading stage, and Rhizobium, Weissella and Lactococcus were the most abundant genera at blooming stage. Higher metabolic activity was found in IB. After 3 days of ensiling, the large amounts of lactic acid in IRH-IB and IRB-IB can be attributed to the higher abundances of Pediococcus and Lactobacillus, 1-phosphofructokinase, fructokinase, l-lactate dehydrogenase and glycolysis I, II and III. The composition, abundance, diversity and functionality of the phyllosphere microbiota of Italian ryegrass at different growth stages could remarkably affect silage fermentation characteristics. © 2023 Society of Chemical Industry.

Spatio-temporal dynamic diversity of bacterial alkaline phosphatase phoD gene and its environmental drivers in sediments during algal blooms: A case study of shallow Lake Taihu

Bacterial alkaline phosphatase encoded by the phoD gene is essential for phosphorus (P) cycling in ecosystems. Until now, knowledge of the phoD gene diversity in shallow lake sediments is still lacking. In this study, from early to late stage of cyanobacterial blooms, we investigated the dynamic changes of the abundance of phoD gene (hereafter phoD abundance) and phoD-harboring bacterial community composition (hereafter phoD-harboring BCC) in sediments from different ecological regions of Lake Taihu, the third-largest shallow freshwater lake in China, as well as explored their environmental driving factors. Results showed that phoD abundance in the sediments of Lake Taihu showed spatiotemporal heterogeneity. The highest abundance was found in macrophyte-dominated area (mean 3.25*106copies/g DW), where Haliangium and Aeromicrobium were identified as the major contributors. Due to the negative impact of Microcystis species, phoD abundance decreased significantly (by 40.28% on average) during cyanobacterial blooms in all other regions except the estuary area. The phoD abundance in sediment was positively correlated with total organic carbon (TOC) and total nitrogen (TN). However, the relationship between phoD abundance and alkaline phosphatase activity (APA) varied with time, showing positive correlation (R2 = 0.763, P < 0.01) in the early stage of cyanobacterial blooms, but not (R2 = −0.052, P = 0.838) in the later stage. The predominant phoD-harboring genera in sediments were Kribbella, Streptomyces and Lentzea, all of which belong to Actinobacteria. Non-metric multidimensional scaling (NMDS) analysis revealed that the spatial heterogeneity of phoD-harboring BCC in the sediments of Lake Taihu was significantly higher than the temporal heterogeneity. TP and sand were the principle environmental factors affecting the phoD-harboring BCC in the sediments of the estuary area, while DO, pH, organic phosphorus (Po) and diester phosphorus were the key driving factors for other lake regions. We concluded that the C, N, and P cycles in sediments might work in concert. This study extends the understanding of the phoD gene diversity in shallow lake sediments.

Effect of Different Organic Sources of Nutrients on Quality and Economics of Ashwagandha [Withania somnifera (L.) Dunal

The present investigation entitled Effect of different organic sources of nutrients on quality and economics of ashwagandha [Withania somnifera (L.) Dunal] was carried out during Kharif 2021-22 at College Farm, College of Horticulture, Sardarkrushinagar Dantiwada Agricultural University, Jagudan, Dist. Mehsana, Gujarat. Experiment was laid out in randomized block design with three replications and twenty treatments viz., T1: 100% RDN through FYM; T2: 100% RDN through Vermicompost; T3: 100% RDN through Neem cake; T4: 100% RDN through Poultry manure; T5: 80% RDN through FYM; T6: 80% RDN through Vermicompost; T7: 80% RDN through Neem cake; T8: 80% RDN through Poultry manure; T9: 60% RDN through FYM; T10: 60% RDN through Vermicompost; T11: 60% RDN through Neem cake; T12: 60% RDN through Poultry manure; T13: 80% RDN through FYM + Azotobacter + KSM + PSB; T14: 80% RDN through Vermicompost + Azotobacter + KSM + PSB; T15: 80% RDN through Neem cake+ Azotobacter + KSM + PSB; T16: 80% RDN through Poultry manure + Azotobacter + KSM + PSB; T17: 60% RDN through FYM + Azotobacter + KSM + PSB; T18: 60% RDN through Vermicompost + Azotobacter + KSM + PSB; T19: 60% RDN through Neem cake + Azotobacter + KSM + PSB; T20: 60% RDN through Poultry manure + Azotobacter + KSM + PSB. Maximum chlorophyll a, b and total at 90 DAS (at full bloom stage) (1.92, 0.75 and 2.11 mg/g, respectively) and withanolides content (0.32%) at harvest were recorded with treatment T16. The maximum net income (₹ 1,38,707/ha) and benefit cost ratio (3.52) were also obtained in same treatment. Therefore, it can be concluded that the application of 80% RDN through poultry manure + Azotobacter + KSM + PSB (T16) was found beneficial for obtaining higher yield of better quality and economic returns in ashwagandha.

Comparative Transcriptome Analysis Identified Potential Genes and Transcription Factors for Flower Coloration in Kenaf (Hibiscus cannabinus L.)

The biochemical compounds in kenaf leaves and flowers mainly consist of flavonoids, including flavonoid glycosides and floral anthocyanins. In the present study, we performed comparative transcriptome analysis using RNA-sequencing and identified putative genes involved in flower coloration in different flower developmental stages of three kenaf mutants including Baekma (white flower), Jangdae (ivory flower), and Bora (purple flower). A total of 36.1 Gb reads were generated for two kenaf accessions and 38,601 representative transcripts with an average length of 1350 bp were yielded, of which 33,057 (85.64%) were annotated against two databases. Expression profiling of the transcripts identified 1044 and 472 differentially expressed genes (DEGs) among three mutants in the young bud and full bloom stages, respectively. KEGG enrichment analysis of these DEGs revealed that the representative pathway was “biosynthesis of secondary metabolites”, including phenylpropanoid biosynthesis and flavonoid biosynthesis. Consequently, we investigated genes related to the phenylpropanoid pathway, which included 45 DEGs from a total of 1358. Our results provide useful information for understanding gene functions of flower coloration in kenaf, which will be useful in further studies.

Methodology and Results of Satellite Monitoring of Karenia Microalgae Blooms, That Caused the Ecological Disaster off Kamchatka Peninsula

The environmental disaster in Kamchatka in the autumn of 2020 was caused by an extensive bloom of harmful microalgae of the genus Karenia. A spectral shape algorithm was used to detect algae on satellite imagery. The algorithm calibration of in situ species composition data made it possible to identify areas where harmful algae dominated in biomass. The algorithm allowed evaluation of the dynamics of the distribution of the algae. The state of phytoplankton was estimated based on images of the specific capacity of photosynthesis. Specific fluorescence is the ratio of the height of the fluorescence line (flh) to the concentration of chlorophyll-a (chl-a). The parameter was used to recognize the stages of the algal bloom: intensive growth, blooming, and change in the dominant algal species. In addition, an increase in the concentration of harmful substances in the coastal zone due to wind impact was analyzed. After analyzing the available data, the events that caused the ecological disaster can be summarized as follows. After the stage of intensive growth of microalgae, nutrient deficiency stimulated the production of metabolites that have a harmful effect on the environment. The change of the dominant alga species in the second half of September and the past storm contributed to a sharp increase in the concentration of metabolites and dead organic matter in the coastal zone, which caused an ecological disaster. The subsequent mass bloom of alga species of the same genus, and the regular wind impact leading to the concentration of harmful substances in the coastal zone, contributed to the development of this catastrophic phenomenon.

Influences of growth stage and ensiling time on fermentation profile, bacterial community compositions and their predicted functionality during ensiling of Italian ryegrass

The study evaluated the effects of growth stage and ensiling time on silage fermentation characteristics, bacterial communities and their predicted functional potential in Italian ryegrass (Lolium multiflorum Lam.) silage. Italian ryegrass (IR) was harvested at heading (Earing rate >50 %, IR1) and blooming stages (>50% bloom, IR2), respectively. The harvested IR was ensiled in 15-L plastic silos. The experiment had a completely randomized design. Triplicate silos were sampled after 1, 3, 7, 15, 30 and 60 days of fermentation, respectively. The fermentation products were analyzed on each sampling day. The bacterial communities and their functional potential and phenotype on day 3 and 60 were analyzed by high-throughput sequencing technique and PICRUSt2 (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) method. With the advancing maturity of IR, the neutral detergent fiber and dry matter (DM) contents, lactic acid bacteria, yeast, Enterobacteriaceae and aerobic bacteria populations increased, while water soluble carbohydrate contents and buffering capacity decreased. Larger lactic acid contents were accumulated in IR1 than IR2 at the early stage of fermentation. Higher contents of ethanol and ammonia nitrogen (NH3-N) were found in IR1 compared to IR2 at the late stage of ensiling. After 60 days, IR1 and IR2 both had good fermentation quality with low pH values (∼4.08), and acceptable levels of NH3-N (∼67.6 g/kg total nitrogen) and butyric acid (∼1.08 g/kg DM). The IR2 had lower abundance of Lactobacillus on day 3, and higher abundances of Kosakonia and Pantoea on day 60 compared to IR1. The bacterial community in IR2 had higher activity in metabolic pathway. Overall, high throughput sequencing technique combined with PICRUSt2 method can improve our understanding of the silage microbiology to further regulate the fermentation products.

Spectral features of ocean colour radiometric products in the presence of cyanobacteria blooms in the Baltic Sea

Cyanobacteria blooms are recurrent in the Baltic Sea with frequency and intensity increasing with temperature. By relying on autonomous multispectral measurements from the Ocean Color component of the Aerosol Robotic Network (AERONET-OC), this study exploited an unprecedented dataset of in situ remote sensing reflectance RRS(λ) spectra (with wavelength λ in the interval 400–667 nm) acquired during filamentous cyanobacteria blooms in the Baltic Sea. The study investigated the temporal evolution of the in situ RRS(λ) during these blooms with particular emphases on those spectral features that may show potential to identify cyanobacteria and their development stages. Additionally, it assessed operational satellite Ocean Colour RRS(λ) products from the Ocean and Land Colour Instrument (OLCI) and Moderate Resolution Imaging Spectroradiometer (MODIS) in the presence of cyanobacteria, for which only qualitative evaluations are available from previous studies. To ascertain to what extent satellite operational data products could be used for cyanobacteria detection in the Baltic Sea, the comparison of in situ and satellite derived RRS(λ) showed poor agreement with differences particularly pronounced at the blue centre-wavelengths. Nevertheless, band-differences in the green-red spectral region for OLCI and for MODIS exhibited less dependence on atmospheric correction issues with mean absolute relative differences between 8.3% and 9.6% for OLCI and between 12.6% and 12.9% for MODIS in the presence of cyanobacteria. Additionally, they showed potential to indicate the presence and development stage of cyanobacteria blooms in Baltic Sea waters while not being sensitive to other algal blooms.

Patterns in sources and forms of nitrogen in a large eutrophic lake during a cyanobacterial harmful algal bloom

AbstractWestern Lake Erie experiences an annual, toxic cyanobacterial harmful algal bloom (cyanoHAB), primarily caused by excess anthropogenic inputs of nitrogen (N) and phosphorous (P). Because the non‐N fixing cyanobacteria species Microcystis dominates these blooms, N availability is hypothesized to play a central role in cyanoHAB progression, as well as production of the N‐rich toxin microcystin. Many previous studies focused on nitrate because it is the most abundant N substrate during bloom initiation. However, recent work implicated reduced N substrates like ammonium and dissolved organic N (DON) in promoting greater bloom biomass and longevity. To examine the relative importance of oxidized and reduced N substrates to phytoplankton during different bloom stages, we measured concentrations and natural abundance δ15N isotope values of dissolved N substrates and phytoplankton biomass throughout the entirety of the 2020 cyanoHAB in Western Lake Erie. The results provide the first data on DON dynamics and composition in Western Lake Erie, and suggest that phytoplankton, including Microcystis, likely relied on N regenerated from the DON pool in later bloom stages. In addition, the stable isotope data confirm the importance of nitrate delivered via the Maumee River to cyanobacterial growth and toxin production.

Elucidating colony bloom formation mechanism of a harmful alga Phaeocystis globosa (Prymnesiophyceae) using metaproteomics

Phaeocystis is a globally distributed Prymnesiophyte genus and usually forms massive harmful colony blooms, which impact marine ecosystem, mariculture, human health, and even threaten coastal nuclear power plant safety. However, the mechanisms behind the colony formation from the solitary cells remain poorly understood. Here, we investigated metabolic processes of both solitary and non-flagellated colonial cells of Phaeocystis globosa at different colony bloom stages in the subtropical Beibu Gulf using a metaproteomic approach. Temperature was significantly correlated with Phaeocystis colony bloom formation, and the flagellated motile solitary cells with abundant flagellum-associated proteins, such as tubulin and dynein, were the exclusive cellular morphotype at the solitary cell stage featured with temperatures ≥21 °C. When the temperature decreased to <21 °C, tiny colonies appeared and the flagellum-associated proteins were down-regulated in both solitary and non-flagellated colonial cells, while proteins involved in biosynthesis, chain polymerization and aggregation of glycosaminoglycan (GAG), a key constituent of gelatinous matrix, were up-regulated, indicating the central role of active GAG biosynthesis during the colony formation. Furthermore, light utilization, carbon fixation, nitrogen assimilation, and amino acid and protein synthesis were also enhanced to provide sufficient energy and substrates for GAG biosynthesis. This study highlighted that temperature induced re-allocation of energy and substances toward GAG biosynthesis is essential for colony bloom formation of P. globosa.

Effect of Flowering Stages on the Content of Active Ingredients and Antioxidant Capability of Bletilla striata Flowers.

Bletilla striata (Thunb.) Reichb.f. is a perennial herb with abundant active ingredients. Previous research mainly focused on its tubers, however, the study on flowers, especially the variation of active ingredient contents at different flowering stages, was rarely seen. This study analyzed the total phenols, flavonoids, polysaccharides, anthocyanins, and cyanidin-3-O-glucoside content of B. striata flowers which were in cultivated in Herb Garden of Zhejiang A&F University and collected in May, 2019, in order to investigate the changes in active ingredients and antioxidant capacity among different flowering stages (bud, initial, and full bloom). Changes in radical scavenging capability of DPPH (1,1-Diphenyl-2-picrylhydrazyl radical), ABTS (2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonate)), and hydroxy were analyzed. Significant differences in active ingredient content of flowers were detected among different flowering stages. The total phenolic content increased continuously during the entire flowering stage. The contents of total flavonoid, total polysaccharide, and cyanidin-3-O-glucoside reached peaks at the initial blooming stage and then fell as the flowering process continued. The antioxidant activity in initial stage was the highest than in any other flowering stages. Therefore, we conclude that the initial blooming stage is the best harvesting stage of B. striata flowers. This study provides a robust basis for the harvest and utilization of B. striata flowers in food, medical, and cosmetic industries.

Chlorination for Microcystis aeruginosa in the Late Lag Phase: Higher Inactivation Efficiency and Lower Environmental Risk

Chlorine is often employed to dispose cyanobacteria-laden waters for inactivating cells or improving its removal efficiency. However, previous studies mostly focused on cyanobacterial blooms occurring in the exponential or stationary phase, and thus, cyanobacterial characteristics in the unblooming stage (lag phase) and their influence on chlorination were not well understood. Herein, Microcystis aeruginosa in late lag and exponential phases with the same cell density were selected to simulate unblooming and blooming stages, respectively, and their response to chlorination was investigated. Compared with the exponential phase, results showed that cyanobacteria in the late lag phase consumed lower chlorine but produced higher intracellular reactive oxygen species (ROS). Then, higher rate constants of photosynthetic activity inactivation (kf) and membrane damage (km) were found in the late lag phase. Chlorine of >1.0 mg L–1 could degrade microcystin in this phase, and microcystin could be oxidized to below 1.0 μg L–1 by 2.0 mg L–1 chlorine. Besides, lower extracellular dissolved organic carbon (DOC), UV absorbance at 254 nm (UV254), and their variation range were also observed in the late lag phase. These findings indicated that the chlorination performance in the two phases is different, and thus, it is necessary to reduce the applied dosage of chlorine to treat cyanobacteria-laden source waters in the (late) lag phase.

Horticultural Practices in Early Spring to Mitigate the Adverse Effect of Low Temperature on Fruit Set in 'Lapins' Sweet Cherry.

Yield of sweet cherry (Prunus avium L.) is determined by fruit set, a developmental stage sensitive to variable spring environmental conditions. To sustain fruit production and enhance crop climate resilience, it is important to understand the impacts of abiotic stresses and the effectiveness of horticultural mitigations in the spring on the critical developmental processes during fruit set. In this study, flowering phenology, pistil browning and percent fruit set of 'Lapins' were monitored at five sites of different elevation and frost risk in the Okanagan Valley, British Columbia, Canada, in 2019 and 2022. At Site 1 in Summerland Research and Development Centre ("SuRDC1"), where a 'Lapins' on Krymsk 5 planting was located in a frost pocket where the crops were exposed to high risk of cold damage in the spring, a series of experiments were conducted to investigate the floral organ viability and percent fruit set under low temperatures, and under the effects of four spring horticultural mitigation measures. Installation of polyethylene sleeves and FAME spray (fatty acid methyl esters-based plant growth regulator, WAIKEN, SST Australia) were implemented in 2019; boric acid spray and postponed irrigation were tested in 2022. Low fruit set at SuRDC1 in both years was associated with severe pistil browning after night temperature dropped below -4 °C in late April. In 2019, the semi-enclosure of polyethylene sleeves led to an increase in the surface temperature (Tsurfae) of floral buds by 2-4 °C, which prolonged the stage of first bloom, delayed petal fall and prevented frost damage on pistils, but led to the decrease in percent fruit set by 77%, due to ovule abortion or cessation of fruitlet development. The early and late sprays of FAME had no significant influence on either abundance of germinated pollen tubes or percent fruit set; however, the potential of late spray in improving pollen abundance and reducing pistil browning requires further investigation. In 2022, the spray of 0.01% boric acid solution led to a decrease in fruit set by 6.95%. Six-week postponement of irrigation starting from full bloom decreased soil moisture, but increased soil temperature and improved fruit set by 7.61%. The results improved our understanding about the damages of adverse spring air temperatures on pistils and ovules, and suggested the potential of irrigation adjustment in regulating soil moisture and temperature and improving fruit set in the cool and moist spring.

Variations in Yield, Essential Oil, and Salicylates of Filipendula ulmaria Inflorescences at Different Blooming Stages.

Meadowsweet (Filipendula ulmaria) is an essential oil-bearing, pharmacologically valuable medicinal plant growing wild in floodlands that are either not usually used for agriculture or have low economic value. The aim of this work was to understand the relationship between the yield of F. ulmaria inflorescences and the qualitative and quantitative composition of the essential oil during flowering stages in different habitats. Five different habitats of F. ulmaria were investigated for evaluation of inflorescence characteristics (length and weight) and the quantitative and qualitative composition of essential oils in early and late blooming stages (growing stage BBCH 62-63 and BBCH 65-67/72-73, respectively). The results showed significant (p &lt; 0.05) positive correlations between the length and weight of inflorescences both in early and in late blooming stages (r = 0.73 and r = 0.72, respectively). The early blooming stage was observed to have 1.2-2 times greater quantity of volatile oils in comparison with the late blooming stage. Salicylaldehyde and methylsalicylate were the main salicylates in both blooming stages. Spearman's correlation showed statistically significant relationship between percentages of salicylaldehyde and methylsalicylate (r = -0.94, p &lt; 0.05). An increase in salicylaldehyde was accompanied by a decrease in methylsalicylate in essential oils. Statistically significant relations between the investigated parameters of plant and the parameters of habitat were not detected. The dried raw material yield of F.&amp;nbsp;ulmaria in 1 ha in the late blooming stage was 18-56% higher than in the early blooming stage; however, the yield of essential oil in the early flowering stage was 1.5-1.6 times higher than in the late flowering stage. The obtained research data suggest that the low economic value of floodlands-the habitats of F. ulmaria-can be increased by using these areas as natural industrial plots.

Study of the Relationship between Biomass and Fractional Green Canopy Cover of Two Forage Crops Using Canopeo®

Rapid and accurate estimation of biomass is crucial for the assessment of the crop nutrition status and the improvement of crop management strategies. The study was conducted in Setif province (Northeast of Algeria). Canopy cover was calculated using Canopeo® application, at stem elongation, booting, and heading stages for triticale, and V5, R1, and R3 for lentil. The results indicate a high correlation between canopy cover and triticale biomass, at the stem elongation stage with R2 = 0.98 and 0.89 under no till and conventional till, respectively. The RMSE was 0.1 and 0.06t/ha, under the two modes. The lowest correlation is seen at heading stage with a value of 0.21 and RMSE of 0.65t/ha, under no till mode. For lentil, the high correlations between are observed at R3 (early pod), and R1 (early bloom) stages, with a coefficients of 0.85 and 0.98, under zero till and conventional respectively. The RMSE was 0.17t/ha. This smartphone application is suitable for assessing triticale and lentil biomass; it is rapid, easy, and could replace the destructive sampling method.

Plow layer management during the fallow season can enhance the wheat productivity and resource utilization in a semi-arid region

The soil quality is poor in the arid areas of Northwest China and planting green manure can improve the soil quality but it also increases the soil water consumption. Straw mulching in the wheat (Triticum aestivum L.) fallow season can improve the soil water content. It is unclear whether green manure can be planted in addition to straw mulching to improve the soil water content and quality. Therefore, a field experiment was conducted in the semi-arid area of the Loess Plateau in China from 2009 to 2017 with the following treatments; (1) traditional bare land in fallow season after plowing (CK), (2) no-tillage with straw mulching (NTSM), (3) and no-tillage with straw mulching and planting soybean as green manure (NTSGM). We determined the effects of these three treatments on the soil water, nutrients, and wheat productivity. Compared with CK, the average soil water contents in 0–100 cm soil depth increased by 11.1% and 3.6% under NTSM and NTSGM, respectively, during the soybean full bloom stage, and by 13.06% and 6.6% before wheat sowing. Compared with CK, the decomposition of green manure increased the NO3–-N contents in the 0–100 cm soil depth by 6.6% and 5.3% under NTSGM before wheat sowing and after harvesting, respectively, and NTSM and NTSGM significantly improved the soil nutrients, microbial biomass contents, and enzyme activities. The superior soil quality and water content under NTSM and NTSGM increased the fertilizer uptake and partial factor productivity. Compared with CK, the average precipitation storage efficiency, water use efficiency during the whole year, biomass, and wheat yield were 32.6%, 23.2%, 16.2%, and 21.6% higher under NTSGM, respectively. Therefore, NTSGM is an effective method for improving the soil water storage and NO3–-N contents before sowing wheat, as well as the water use efficiency, soil quality, utilization of nutrients, and wheat productivity in semi-arid areas of the Loess Plateau.

PRIMARY PRODUCERS SIZE STRUCTURE IN THE MARGINAL ICE ZONE OF EUROPEAN ARCTIC IN SUMMER

Primary production (PP) and chlorophyll “a” concentration (chl “a”) estimates in the Eurasian Arctic are discussed, where the continued climatic warming with increased “Atlantification” advance the sea ice losses. The maximum integrated PP and the total chl “a” content observed in the marginal ice zone (MIZ) of the Barents Sea with weakened stratification of the water column and reached 1109 mgC m–2 day–1 and 118 mg m–2. Nearby the ice edge in the Nansen Basin, the main part of PP formed in the upper mixed layer and did not exceed 469 mgC m–2 day–1, the chl “a” content of 56 mg m–2. In the early and late phytoplankton bloom in MIZ, the typical leading role of picophytoplankton in carbon fixation revealed. Large centric diatoms, microphytoplankton, dominated at the peak bloom stage in 2020 with the dense marine ice cover of the Nansen Basin. A similar phenomenon was previously observed only in the Arctic shelf seas and was not recorded in the high-latitude basins of the Arctic Ocean. With the sparse ice cover of the Nansen Basin in 2021, the main primary producers at the peak bloom were pico- and nanophytoplankton. The low variability of assimilation numbers at all bloom stages (1.7 ± 0.3 mgC mg chl “a”–1 h–1) indicates the acclimatization of phytoplankton to changing environment. The ecological flexibility of the primary production are link of the MLZ ecosystems in the studied seas of the European Arctic during the period of climate change is confirmed.

Marigold Flower Blooming Stage Detection in Complex Scene Environment using Faster RCNN with Data Augmentation

In recent years, flower growing has developed into a lucrative agricultural sector that provides employment and business opportunities for small and marginal growers in both urban and rural locations in India. One of the most often cultivated flowers for landscaping design is the Marigold flower. It is also widely used to create garlands for ceremonial and social occasions using loose flowers. Understanding the appropriate stage of harvesting for each plant species is essential to ensuring the quality of the flowers after they have been picked. It has been demonstrated that human assessors consistently used a category scoring system to evaluate various flowering stages. Deep learning and convolutional neural networks have the potential to revolutionize agriculture by enabling efficient analysis of large-scale data. In order to address the problem of Marigold flower stages detection and classification in complex real-time field scenarios, this study proposes a fine-tuned Faster RCNN with ResNet50 network coupled with data augmentation. Faster RCNN is a popular deep learning framework for object detection that uses a region proposal network to efficiently identify object locations and features in an image. The Marigold flower dataset was collected from three different Marigold fields in the Anand District of Gujarat State, India. The collection includes of photos that were taken outdoors in natural light at various heights, angles, and distances. We have developed and fine-tuned a Faster RCNN detection and classification model to be particularly sensitive to Marigold flowers, and we have compared the generated method's performance to that of other cutting-edge models to determine its accuracy and effectiveness.

Accumulation patterns of major bioactive components in two chemotypes of Agastache rugosa during flower development evaluated by GC-QQQ-MS/MS and UPLC-QTOF-MS/MS analyses

Agastache rugosa (AR) is a wildly cultivated medicinal and aromatic crop, which usually recommended to be harvested when the plant is exuberant with not flowering or in full flower stage. But there is no scientific basis for the support of the cognition. Therefore, the accumulation patterns of major active components during flower development (inflorescences with buds, full bloom and after full bloom stages) in two chemotypes (menthone type and estragole type) of AR were investigated by newly developed GC–QQQ–MS/MS and UPLC–QTOF–MS/MS methods. Five volatile (pulegone, menthone, estragole, methyleugenol and β -caryophyllene) and nine non-volatile components (rosmarinic acid, tilianin, acacetin 7- O -(6"- O -malonyl)- β - D -glucopyranoside, apigenin, agastachoside, isoagastachoside, acacetin 7- O -(2"- O -acetyl-6"- O -malonyl)- β - D -glucopyranoside, cirsimaritin and acacetin) in two chemotypes of AR samples at three stages were simultaneously quantified. It was found that the relatively higher contents of main volatile components were present in menthone type of AR collected at the full flower stage and in estragole type of AR at the after full bloom stage, whereas the relatively higher contents of main non-volatile components were present in menthone type of AR collected at the inflorescences with buds stage and in estragole type of AR at the after full bloom stage. Considering major active volatile and non-volatile components with higher levels, full bloom stage and after full bloom stage should be optimal harvesting time for menthone type and estragole type of AR, respectively. • GC–QQQ–MS/MS and UPLC–QTOF–MS/MS methods developed to quantify components of AR. • Both menthone and estragole chemotype AR at flowering stages were investigated. • Accumulation patterns of both volatile and non-volatile components of AR were revealed. • Full bloom and after full bloom stage are optimal harvesting time for menthone and estragole type of AR.