Leaf Chlorophyll Index Research Articles

Pengaruh Bakteri Pelarut Fosfat terhadap Pertumbuhan dan Hasil Kedelai pada Pertanaman Kelapa Sawit TM-I

Wide space among oil palm Mature Stage I (MS I) plantations has a potential to be planted with soybean by using intercropped system. One type of soil in oil palm plantations in Indonesia is Inceptisol which generally has low P availability. Efforts possible to increase P availability are the applications of inorganic P fertilizer and phosphate solubilizing bacteria (PSB). This study aims to learn the effects of various inorganic P fertilizer and PSB doses on the growth and yield of soybean in oil palm MS I plantation and determine the effects of intercropping soybean on the growth and physiology of oil palm MS I. The research was conducted at Ciparanje Experimental Field, Faculty of Agriculture, Universitas Padjadjaran, from February to May 2023. The study used randomized block design with seven treatments and four replications. Treatment consisted of different doses of Bacillus sp. and SP36 which included: 100% SP36, 50 kg/ha PSB + 25% SP36, 50 kg/ha PSB + 50% SP36, 50 kg/ha PSB + 75% SP36, 75 kg/ha PSB + 25% SP36, 75 kg/ha PSB + 50% SP36, and 75 kg/ha PSB + 75% SP36. Results showed PSB and P fertilizer had a significant effect on the dry weight of 100 seeds and leaf chlorophyll index of soybean. Dose of 50 kg/ha PSB + 50% SP36 increased the dry weight of 100 seeds by 3,99% and leaf chlorophyll index by 15,35%.

Métodos de inoculação de Azospirillum brasilense em alface e rúcula em sistema hidropônico

ABSTRACT: Lettuce and arugula are the most cultivated leafy vegetables in hydroponic systems in the world, and the little information about Azospirillum brasilense effects in research in this system makes it necessary to verify the best method of inoculation of these bacteria. Therefore, this study aimed to verify the beneficial effects of inoculation methods of A. brasilense on plant growth and nutrition of lettuce and arugula grown in the hydroponic system. The study was conducted in a greenhouse with 30% shading. A randomized block design with five replicates in a 4 × 2 factorial scheme was used. Four A. brasilense inoculation methods (non-inoculated, foliar application, nutrient solution, and nutrient solution + foliar application) and two leafy vegetable species - arugula and lettuce - were evaluated. All inoculation methods improved plant height, shoot fresh and dry mass, root fresh and dry mass, fresh leaf yield, leaf chlorophyll index, accumulation of nitrogen, potassium, calcium, sulfur, phosphorus, iron, manganese, and copper and reduced nitrate accumulation in shoot and root of arugula and lettuce. Inoculation via nutrient solution + foliar application of A. brasilense is the most suitable for hydroponic arugula cultivation because it provides greater fresh leaf yield. All inoculation methods increased leaf yield in hydroponic lettuce. Hydroponic arugula and lettuce plants showed greater accumulation of nutrients and plant growth with less nitrate accumulation in the shoot under inoculation with A. brasilense.

Comparing Six Vegetation Indexes between Aquatic Ecosystems Using a Multispectral Camera and a Parrot Disco-Pro Ag Drone, the ArcGIS, and the Family Error Rate: A Case Study of the Peruvian Jalca

A Parrot Sequoia four-band multispectral camera mounted on a Parrot Disco-Pro Ag drone allowed us to study six vegetation indexes in four lakes within the Tilacancha Private Conservation Area (PCA) in 2021. These lakes are a source of water for consumption for more than 32,000 people in the province of Chachapoyas in the Amazon region of Peru. To obtain the six vegetation indexes (Green Normalized Difference Vegetation Index—GNDVI; Leaf Chlorophyll Index—LCI; Modified Chlorophyll Absorption in Reflective Index—MCARI; Normalized Difference Red Edge—NDRE; Normalized Difference Vegetation Index—NDVI; and Structure Intensive Pigment Index 2S—SIPI2), Pix4DFields 1.8.1 software was used. The sensitivity and distribution of pixel values were compared in histograms and Q–Q plots for each index. Statistical differences were established for each index, and the SIPI2 obtained the highest level of sensitivity concerning the degree of pixel distribution in the ranges shown in the histogram according to the standard deviation; however, the values of all the indexes were not disregarded, because they showed statistical differences between lakes despite their closeness. The family error rate and Tukey-Kramer HSD statistics allowed for establishing statistical differences between pairs of lakes. The six vegetation indexes can be used to detect and analyze the dynamics of biological beings with photosynthetic activity in aquatic ecosystems of the Peruvian Jalca.

Nano-zinc and plant growth-promoting bacteria is a sustainable alternative for improving productivity and agronomic biofortification of common bean

Background and aimsNano-zinc (Zn) fertilizer is an easily adaptable and environmentally safe alternative option that can effectively improve growth, yield and biofortification of common bean. Plant growth-promoting bacteria (PGPBs) could promote plant growth and nutrients availability in sustainable manner. Therefore, this study aimed to investigate the influence of foliar nano-Zn application in association with seed co-inoculations of PGPBs on growth, yield, biofortification and Zn use efficiencies in common bean cultivation. Two field experiments were performed with seven co-inoculations of PGPBs and three foliar nano-Zn doses applied 50% at R5 and 50% at R8 stages of common bean to determine plant height, shoot dry matter, grain yield, Zn concentration and uptake in shoot and grains, Zn partitioning index, daily Zn intake and Zn use efficiencies for agronomic biofortification.ResultsThe combined foliar nano-Zn application and co-inoculation of R. tropici + B. subtilis enhance grain yield, leaf chlorophyll index, total protein content, grain Zn concentration and uptake, daily Zn intake, Zn use efficiency, applied Zn recovery and Zn utilization efficiency in common beans in 2019 and 2020 cropping seasons. Foliar nano-Zn application at a dose of 1.5 kg ha−1 increased plant height, shoot dry matter, shoot Zn uptake, Zn partitioning and agro-physiological efficiency under co-inoculation with R. tropici + B. subtilis in both cropping years.ConclusionsThe treatments with foliar nano-Zn application at a dose of 1.5 ha−1 and co-inoculation with R. tropici + B. subtilis improved performance, chlorophyll index, protein content, grain yield, and Zn efficiencies that can lead to better biofortification of common bean in tropical savannah. Therefore, it is recommended that applying nano-Zn via foliar along with co-inoculation of PGPBs could be the better option for productivity and biofortification of common bean.Graphical

Phenological stage and vegetation index for predicting corn yield under rainfed environments.

Uncrewed aerial systems (UASs) provide high temporal and spatial resolution information for crop health monitoring and informed management decisions to improve yields. However, traditional in-season yield prediction methodologies are often inconsistent and inaccurate due to variations in soil types and environmental factors. This study aimed to identify the best phenological stage and vegetation index (VI) for estimating corn yield under rainfed conditions. Multispectral images were collected over three years (2020-2022) during the corn growing season and over fifty VIs were analyzed. In the three-year period, thirty-one VIs exhibited significant correlations (r ≥ 0.7) with yield. Sixteen VIs were significantly correlated with the yield at least for two years, and five VIs had a significant correlation with the yield for all three years. A strong correlation with yield was achieved by combining red, red edge, and near infrared-based indices. Further, combined correlation and random forest an alyses between yield and VIs led to the identification of consistent and highest predictive power VIs for corn yield prediction. Among them, leaf chlorophyll index, Medium Resolution Imaging Spectrometer (MERIS) terrestrial chlorophyll index and modified normalized difference at 705 were the most consistent predictors of corn yield when recorded around the reproductive stage (R1). This study demonstrated the dynamic nature of canopy reflectance and the importance of considering growth stages, and environmental conditions for accurate corn yield prediction.

Role of Mineral Micronutrient on some Qualitative Traits and Yield of Sweet Pepper Under Protected Cultivation System in Calcareous Soil

In the 2020/2021 agricultural season, a private greenhouse farm in Al-Madaen city/Old Diyala Bridge/Western Tuwaitha Village (N 44,29,47-E 36,33,11) studied the influence of mineral micronutrients on biofortification, growth, and yield of sweet pepper cultivated on calcareous soil. Dutch Oloumpus peppers were planted. The plastic home grew seedlings on 11/11/20202. Nutrients (50 mg Fe) were employed. 60 mg Zn/L. 30 mg Mn/L. L-1 and 25 mg Cu. L-1) of the following salts: ferrous sulfate FeSO4.7H2O Fe=20%, zinc sulfate ZnSO4.7H2O Zn=22.78%, manganese MnSO4.H2O Mn=32.54%, copper CuSO4.5H2O Cu= 25.45%, successively. The split plot design factor experiment had three replications and two techniques of delivering nutrients: spraying the shoots and irrigation. Each technique of addition had 16 treatments, including single, double, triple, and quadruple additions of the nutrients employed in the experiment plus a reference treatment. The first addition came after two weeks of field cultivation, and subsequent addition was one week apart. N, P, and K were utilized at 425, 175, and 250 kg.h-1, respectively. The Fe treatment of irrigation water and the Fe+Mn+Cu treatment of sprayed shoots yielded the greatest vitamin C content of 23.57 mg.100gm-1 fresh weight. The Fe+Mn+Cu treatment had the greatest total soluble solids (TSS) value of 5.8, and all spray application treatments outperformed irrigation water on the vegetative system. Fe+Cu had the highest leaf chlorophyll index of 74.68. The maximum cumulative output was 159.15 Mg.h-1 for Fe+Zn+Mn spraying on shoots.

Evaluation of Wheat Genotypes under Water Regimes Using Hyperspectral Reflectance and Agro-Physiological Parameters via Genotype by Yield*Trait Approaches in Sakha Station, Delta, Egypt

Drought is an environmental abiotic stress that diminishes wheat production worldwide. In the present study, we evaluated fifty bread wheat genotypes (arranged in alpha lattice design) under two main water regimes, water-deficit (two surface irrigations) and well-watered (four irrigations), at different sites in two consecutive cropping seasons, 2019/20 and 2020/21. To identify the drought-tolerant genotypes, utilized several selection/phenotyping criteria, including agronomic traits, e.g., grain yield (GY) and yield components (SM); physiological parameters such as canopy temperature (CT), leaf transpiration rate (TRN), intercellular CO2 concentration (INCO); spectral reflectance indices, e.g., Leaf Chlorophyll Index (LCI), curvature index (CI), and normalized difference vegetation index (NDVI); and stress tolerance indices (STI) were determined concurrently with the grain yield. The results revealed significant differences (p ≤ 0.01) among the environments, genotypes, and their interaction for grain yield (GY), days to heading (DH), days to maturity (DM), grain filling period (GFP), grain filling rate (GFR), Normalized difference vegetation index (NDVI), plant height (PH), and spikes per square meter (SM). The genotype plus genotype by environment (GGE) and genotype by yield*trait (GYT) biplot techniques indicated that Genotype 37 (Sakha 95) and Genotype 45 performed best under well-watered and water-deficit environments. Furthermore, the same genotypes were the best from the genotype by stress tolerance indices (GSTI) approach view. Genotype 37 (Sakha 95) was superior to the GYT selection method, with physiological parameters and spectral reflectance indices. Likewise, we can identify this genotype as low-water-tolerant based on GSTI, GYT, and SRI results and recommend involving it in the drought breeding program.

Inoculation reduces nitrate accumulation and increases growth and nutrient accumulation in hydroponic arugula

Inoculation with plant growth-promoting bacteria (PGPBs) has remarkably increased yield and nutrient uptake of crop plants. The objective of this study was to evaluate the effect of bacterial inoculation with Azospirillum brasilense, Bacillus subtilis and Pseudomonas fluorescens on growth, accumulation of nutrients as well as NNH4+ and NNO3− in hydroponic arugula plants. The research was carried out in a nutrient film technique (NFT) system and designed in randomized blocks with 5 replications. The treatments consisted of inoculation with A. brasilense, B. subtilis and P. fluorescens via nutrient solution at a dose of 0.1 mL L−1 and without inoculation treatment. Inoculation with P. fluorescens promoted NNH4+ accumulation in shoots and roots by 311% and 119% respectively as compared to non-inoculated plants. Inoculations with A. brasilense, B. subtilis and P. fluorescens reduced NNO3− accumulation in shoots and roots by18 and 14% as compared to without inoculation treatments. Fresh and dry mass of roots, root volume and leaf chlorophyll index were increased with inoculation of P. fluorescens and being considered the most suitable inoculant for hydroponic arugula cultivation. Inoculation with A. brasilense, P. fluorescens and B. subtilis reduced shoot NNO3− accumulation, thus benefiting human health.

Analysis of the Vigor of Pinus hartwegii Lindl. along an Altitudinal Gradient Using UAV Multispectral Images: Evidence of Forest Decline Possibly Associated with Climatic Change

Future climate forecasts predict major changes that will have negative impacts on the distribution, abundance, and dynamics of forest ecosystems. In Mexico, there is evidence of symptoms of massive forest decline; however, there is no consensus in terms of attributing these symptoms to climate change. This study aimed to provide evidence of forest decline possibly associated with climatic change in the highland pine (Pinus hartwegii Lindl.) populations of the Nevado de Toluca Flora and Fauna Protection Area. Using unmanned aerial vehicles (UAV) equipped with multispectral sensors, the study applied digital photogrammetry techniques, automated tree crown detection algorithms, and calculation of the normalized difference vegetation index (NDVI) and leaf chlorophyll index (LCI) to assess forest health across an altitudinal transect (from 3300 m to the timberline at 4040 m elevation). Climate analysis was conducted with TerraClimate data using mean annual temperature (MAT), April temperature, and Palmer Drought Severity Index (PDSI) from the studied altitudinal transect and its xeric limit. We found that lower altitude populations had significantly higher stress levels, indicating forest decline phenomena, while intermediate altitude populations showed greater vigor of the detected trees. Statistically significant differences in the NDVI and LCI values along the altitudinal gradient provided evidence of forest decline in terms of forest vigor and productivity, with the greatest disturbance found at the lower altitude of the examined forest species. The analysis of the climatic data revealed an increase in April temperature +1.4 °C of the xeric limit of the transect (low altitude) when comparing the reference period, 1961–1990 (mean: 12.17 °C), with the decade prior to our study (2011–2020; mean: 13.57 °C). This would be equivalent to an upward shift in elevation of 280 m of the xeric limit. In addition, the PDSI analysis revealed that droughts are becoming increasingly intense at a rate of 0.06 PDSI units per decade, with greater intensity in the last five years. These findings highlight the negative impacts of climate change on forest ecosystems and the urgent need for alternative forest management and conservation practices to increase resilience and adaptation in the temperate forests of Mexico. This study sets a precedent for further research to improve our understanding of the impacts of climate change on forest ecosystems and the development of sustainable management practices.

Waterlogging Effects on Soybean Physiology and Hyperspectral Reflectance during the Reproductive Stage

In humid climates, waterlogging from excessive rainfalls can be a major limiting factor for soybean production, particularly during the reproductive stage. However, there is a limited understanding of how soybean growth and physiology respond to waterlogging during this critical stage. Here, we investigated the effects of waterlogging and subsequent reoxygenation on the growth, physiology, yields, and leaf hyperspectral reflectance traits of the soybean cultivar ‘Asgrow AG5332’. The crop was grown to stage R1 (initial flowering) in outdoor pot culture conditions, and then waterlogged for 16 days. The flooded pots were drained and continuously monitored for recovery for an additional 16 days. The results showed that soil oxygen levels declined rapidly to zero in about 5 days after waterlogging, and slowly recovered in about 5–16 days. However, it did not reach the same level as the control plants, which maintained an oxygen concentration of 18%. Increasing waterlogging duration negatively affected leaf chlorophyll index, water potential, and stomatal conductance, with a consequent decline in the photosynthetic rate. Further, decreased photosynthetic rate, leaf area, and mineral nutrients resulted in lower biomass and seed yield. Pod dry weight and leaf number were the most and least sensitive parameters, respectively, decreasing by 81% and 15% after 16 days of waterlogging. Waterlogged plants also had higher reflectance in the PAR, blue, green, and red regions, and lower reflectance in the near-infrared, tissue, and water band regions, indicating changes in chemistry and pigment content. The current study reveals that the soybean crop is susceptible to waterlogging during the reproductive stage, due to poor recovery of soil oxygen levels and physiological parameters. Understanding and integrating the growth, physiology, and hyperspectral reflectance data from this study could be used to develop improved cultivars to ensure the stability of soybean production in waterlogging-prone areas.

Morphophysiological dynamics of Casearia sylvestris seedlings under different natural irradiation conditions

Knowledge of the ability of species to acclimate to light environments allows for the most appropriate selection for the restoration of different sites. Casearia sylvestris Sw. is a species C3 with important functional characteristics, geographic distribution and described for its plasticity, and was used as a reference for the present investigation. Thus, this study aims to investigate the morphophysiological changes of species planted in pots under different conditions: High irradiance (full sun around 106175 ± 1.246 lux), moderate irradiance (moderate shade under 61775 ± 2.333 lux), and low irradiance (understory under 425 ± 57 lux). The sampling design was a totally random design. The survival rate was calculated by the total number of seedlings per treatment. For the other analyzes (variables) 5 random repetitions were used for the evaluations. We found that the plants altered their morphophysiological characteristics with varying light intensity. Under higher light availability, the species responded with increased photosynthetic rates, stomatal conductance, transpiration, survival (100%), reduced specific leaf area, pigment reduction, quantum yield of photosystem II. In the understory (425 ± 57 lux), the species modulates the photosynthetic apparatus, increasing chlorophyll concentration and specific leaf area, seeking to increase light capture, with a survival rate of 86%. The variables with the highest plasticity index were predominantly physiological (transpiration, stomatal conductance, photosynthesis, and photochemical quenching) and they contributed most to the acclimation process. It was confirmed by the plasticity index analysis, where the least plastic variables were specific leaf area and chlorophyll index total, water use efficiency, and photosystem II quantum efficiency. It is concluded that the plasticity of the species to light intensity is provided by aspects related to the photosynthetic capacity of plants, providing a higher rate of survival and growth in plants without water or nutritional restriction.

NO 3 – , K + , and chlorophyll index in fertigated grapevines in the semi-arid region of Brazil

Evaluating the effects of N and K supply on grapevines ( Vitis vinifera L.) and the techniques for nutritional diagnosis is of great importance for fertigation management of this crop. This study evaluated the effects of N and K fertigation on the soluble concentrations of NO 3 – and K + in the petiole sap and on the leaf chlorophyll index in drip irrigated ‘Syrah’ grapevine (from 17 June 2013 to 25 Nov 2014). The treatments consisted of five levels of N (0, 15, 30, 60 and 120 kg ha –1 ) and K 2 O (0, 15, 30, 60 and 120 kg ha –1 ), combined in an incomplete 5 2 factorial scheme in 13 combinations and arranged in randomized blocks with four replications. We determined NO 3 – and K + concentrations in petiole sap, leaf chlorophyll index, grapevine cluster mass and number per plant, mean grapevine cluster mass, and phenolic composition. High NO 3 – concentrations contributed positively to grapevine yield; however, increased K+ concentrations caused a negative response of sap. For 120 kg N ha –1 rate, NO 3 – in the sap and chlorophyll index showed higher values at the flowering stage, while high values for K + were observed during the grape-ripening stage.

The roles of species' relatedness and climate of origin in determining optical leaf traits over a large set of taxa growing at high elevation and high latitude.

Climate change is driving many mountain plant species to higher elevations and northern plant species to higher latitudes. However, various biotic or abiotic constraints may restrict any range shift, and one relevant factor for migration to higher elevations could be species' ability to tolerate high UV-doses. Flavonoids are engaged in photoprotection, but also serve multiple ecological roles. We compared plant optical leaf trait responses of a large set of taxa growing in two botanical gardens (French Alps and southern Finland), considering potential constraints imposed by the relatedness of taxa and the legacy of climatic conditions at plants' original collection sites. The segregation of optically measured leaf traits along the phylogeny was studied using a published mega-tree GBOTB.extended.tre for vascular plants as a backbone. For a subset of taxa, we investigated the relationship between climatic conditions (namely solar radiation, temperature and precipitation at a coarse scale) at the plants' original collection site and current trait values. Upon testing the phylogenetic signal (Pagel's λ), we found a significant difference but intermediate lambda values overall for flavonol or flavone index (Iflav) and anthocyanin index (Iant), indicating that phylogenetic relatedness alone failed to explain the changes in trait values under a Brownian motion model of trait evolution. The local analysis (local indicator of phylogenetic association) indicated mostly positive autocorrelations for Iflav i.e. similarities in optically measured leaf traits, often among species from the same genus. We found significant relationships between climatic variables and leaf chlorophyll index (Ichl), but not Iflav, particularly for annual solar radiation. Changes in plants' Iflav across microhabitats differing in UV irradiance and predominately high F v /F m indicated that most plants studied had sufficient flexibility in photoprotection, conferred by Iflav, to acclimate to contemporary UV irradiances in their environment. While not explaining the mechanisms behind observed trait values, our findings do suggest that some high-elevation taxa display similar leaf flavonoid accumulation responses. These may be phylogenetically constrained and hence moderate plants' capacity to adjust to new combinations of environmental conditions resulting from climate change.

Grapevine leaf physiology and morphological characteristics to elevated CO2 in the VineyardFACE (Free air Carbon dioxide Enrichment) experiment.

Atmospheric carbon dioxide (CO2) concentration has continuously increased since pre-industrial times and has currently reached an average growth rate of 2.3 ppm per year. For the majority of plant species elevated CO2 (eCO2) improves photosynthesis and thus plant biomass production. To investigate the effects of eCO2 on leaf physiology and morphological leaf characteristics two Vitis vinifera L. cultivars, Riesling and Cabernet Sauvignon, grown in the VineyardFACE (Free Air Carbon dioxide Enrichment) system were used. The VineyardFACE is located at Geisenheim, Rheingau comparing future atmospheric CO2-concentrations (eCO2, predicted for the mid-21st century) with current ambient CO2-conditions (aCO2). Experiments were operated under rain-fed conditions for two consecutive years (2015 and 2016). For both varieties and CO2 treatments, leaf gas exchange measurements were performed as well as measures of epidermal flavonoid (Flav) and leaf chlorophyll (Chl) indices by using a portable leaf clip. Furthermore, leaves were sampled for spectrophotometric analysis of the leaf pigments chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoid (Car). Additionally, leaf cross-sections were produced as permanent preparations to investigate morphological characteristics of the leaf structure. Both cultivars did not differ in leaf chlorophyll meter readings or leaf pigments between the two CO2 treatments while net assimilation was highly stimulated under elevated CO2 for both seasons. Differences found in leaf cross-sections were detected in palisade parenchyma and epidermal thickness of Cabernet Sauvignon under eCO2, whereas Riesling net assimilation increased by 40% under a 20% CO2 enrichment while remaining unaffected in different leaf layer thickness. The observed results within grapevine leaf tissues provide insights to seasonal adaptation strategies of grapevines under elevated CO2 concentrations predicted in future.

Azospirillum brasilense and Zinc Rates Effect on Fungal Root Colonization and Yield of Wheat-Maize in Tropical Savannah Conditions.

A successful microbial inoculant can increase root colonization and establish a positive interaction with native microorganisms to promote growth and productivity of cereal crops. Zinc (Zn) is an intensively reported deficient nutrient for maize and wheat production in Brazilian Cerrado. It can be sustainably managed by inoculation with plant growth-promoting bacteria and their symbiotic association with other microorganisms such as arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE). The objective of this study was to evaluate the effect of Azospirillum brasilense inoculation and residual Zn rates on root colonization and grain yield of maize and wheat in succession under the tropical conditions of Brazil. These experiments were conducted in a randomized block design with four replications and arranged in a 5 × 2 factorial scheme. The treatments consisted of five Zn rates (0, 2, 4, 6 and 8 kg ha-1) applied from zinc sulfate in maize and residual on wheat and without and with seed inoculation of A. brasilense. The results indicated that root colonization by AMF and DSE in maize-wheat cropping system were significantly increased with interaction of Zn rates and inoculation treatments. Inoculation with A. brasilense at residual Zn rates of 4 kg ha-1 increased root colonization by AMF under maize cultivation. Similarly, inoculation with A. brasilense at residual Zn rates of 2 and 4 kg ha-1 reduced root colonization by DSE under wheat in succession. The leaf chlorophyll index and leaf Zn concentration were increased with inoculation of the A. brasilense and residual Zn rates. The inoculation did not influence AMF spore production and CO2-C in both crops. The grain yield and yield components of maize-wheat were increased with the inoculation of A. brasilense under residual Zn rates of 3 to 4 kg ha-1 in tropical savannah conditions. Inoculation with A. brasilense under residual Zn rates up to 4 kg ha-1 promoted root colonization by AMF and DSE in the maize cropping season. While the inoculation with A. brasilense under 2 and 4 kg ha-1 residual Zn rates reduced root colonization by AMF and DSE in the wheat cropping season. Therefore, inoculation with A. brasilense in combination with Zn fertilization could consider a sustainable approach to increase the yield and performance of the maize-wheat cropping system in the tropical savannah conditions of Brazil.

UAV-Derived Spectral Indices for the Evaluation of the Condition of Rye in Long-Term Field Experiments

The aim of the study was to evaluate the effect of various fertilization treatments, including nitrogen, potassium and phosphorus fertilization, in long-term experiments for selected UAV (unmanned aerial vehicle)-derived spectral vegetation indices (NDVI—Normalized Difference Vegetation Index, NDRE—Normalized Difference Red Edge Index, VARI—Visible Atmospherically Resistant Index, TGI—Triangular Greenness Index, SIPI2—Structure Insensitive Pigment Index 2, LCI—Leaf Chlorophyll Index, BNDVI—Blue Normalized Difference Vegetation Index, GNDVI—Green Normalized Difference Vegetation Index, MCARI—Modified Chlorophyll Absorption in Reflective Index) based on multispectral (bands in the range of visible light and near infra-red) images of winter rye. The strongest effect on the studied vegetation indices was nitrogen fertilization, which discriminated values of most of the vegetation indices. The effect of phosphorus and potassium fertilization on the studied vegetation indices was much weaker. The treatments with nitrogen fertilization had significantly higher values of most vegetation indices in comparison to treatments without nitrogen. This was confirmed by principal component analysis (PCA), in which treatments without nitrogen fertilization were very different in comparison to all other treatments where nitrogen fertilization was applied. The effect of phosphorus and potassium fertilization on most of vegetation indices was relatively weak and not significant in most experiments. Only for rye cultivated in monoculture was the effect of phosphorus fertilization significant for most of vegetation indices in early growth stages. In later growth stages (heading and flowering) the effect of phosphorus fertilization was significant in rye monoculture for the SIPI2 vegetation index. Mean SIPI2 was higher for the fertilization treatment CaNPK in comparison to CaKN (without P fertilization). The effect of potassium fertilization on the studied vegetation indices was very weak, and in most cases not significant. The effect of nitrogen fertilization on vegetation indices was much stronger than effect of both potassium and phosphorus fertilization.

Leaf photosynthesis and yield response of winter green gram (Vigna radiata) to high temperature and elevated CO2 in the soil plant atmosphere research (SPAR)

Legumes play an important role in India’s food security, inflation rate and export values. Climate variability might significantly affect the growth, development and yield of legume crops in various regions of the globe. The present study investigated the long episodes effect of high temperature and CO2 and ambient conditions on leaf photosynthesis and yield attributes of green gram (Vigna radiata) using soil plant atmospheric research (SPAR). Green gram was grown under high day temperature (HDT) (day maximum temperature + 3oC) and elevated CO2 (600ppm) (HDT and eCO2), high day and night temperature (HDNT) (day maximum temperature + 3oC) and elevated CO2 (600ppm) (HDNT and eCO2) and ambient conditions. Leaf photosynthesis, stomatal conductance, transpiration rate and chlorophyll index were significantly (p=0.05) increased by 25%, 24.1%, 23% and 4.6%, respectively, under HDT and eCO2 from 30 to 45 DAS (days after sowing) in comparison with ambient and HDNT and eCO2. The significant increase in number of flowers shed per plant increased under HDNT and eCO2 by 13% during 45 to 60 DAS. The increase in the number of pods per plant and grain yield per plant under HDT and eCO2 during 45 to 60 DAS by 26.9% and 25.7%, respectively. However, the biomass of the green gram was increased under HDNT and eCO2 during 30 to 45 DAS. These studies indicated a significant increase in leaf photosynthesis and yield of green gram under HDT and eCO2 at flower initiation to pod development stage (30 to 60 DAS) followed by HDNT and eCO2 and ambient condition. Overall study indicated that increasing temperature and CO2 would increase the biomass and yield of the green gram.

Bacillus velezensis QA2 Potentially Induced Salt Stress Tolerance and Enhanced Phosphate Uptake in Quinoa Plants.

Plant Growth-Promoting Rhizobacteria (PGPR) have attracted much attention in agriculture biotechnology as biological inputs to sustain crop production. The present study describes a halotolerant phosphate solubilizing bacterium associated with quinoa plant roots. Based on a metabolic screening, one bacterial isolate, named QA2, was selected and screened for PGPR traits. This isolate solubilized both inorganic phosphate and zinc, produced indole-3-acetic acid, ammonia, hydrogen cyanide, cellulase, and (to be deleted) protease, and induced biofilm formation. We demonstrated that QA2 exhibited both antimicrobial and ion metabolism activities and tolerated high salt concentration at up to 11% NaCl. Genotyping analyses, using 16S rRNA and chaperonin cpn60 genes, revealed that QA2 belongs to the species of Bacillus velezensis. Using the quinoa model cultivated under a saline condition, we demonstrated that QA2 promoted plant growth and mitigated the saline irrigation effects. Analysis of harvested plants revealed that QA2 induced a significant increase of both leaf chlorophyll index by 120.86% (p < 0.05) and P uptake by 41.17% (p < 0.05), while the content of Na+ was drastically decreased. Lastly, a bibliometric data analysis highlighted the panoramic view of studies carried out so far on B. velezensis strains. Our investigation presents a holistic view of the potential application of B. velezensis as a biological inoculant to promote plant growth, control pathogen attacks, and mitigate the salinity effect of quinoa plants. Further investigations are still needed to demonstrate these effects in field conditions.

The Influence of Applications of Bio-Inputs Derived from Macroalgae and Bacteria on a Phaseolus vulgaris L. Crop

The common bean (Phaseolus vulgaris L.), is one of the most relevant legumes worldwide, as a source of protein, fiber, carbohydrates, and biologically important minerals. In recent decades, bean production increased significantly, especially in developing countries, where the availability of animal protein is often in short supply. However, a large portion of this agricultural production has been achieved in an unsustainable manner, through the intensive use of non-renewable agrochemicals, which in both the short and long term negatively affect soil fertility. To address this problem, the use of sustainable and renewable bio-inputs derived from macroalgae, and microorganisms may be amongst solutions required. Extracts of seaweeds have been shown to be biodegradable and non-toxic both for treated plants and consumers. This study aimed to evaluate the influence of the application of three bio-inputs made from different organisms on a common bean variety (BRSMG Realce) by analysing plant physiology and productivity, pod morphology, nutritional and mineral characterization of the bean. The study also aimed to evaluate the length of BRSMG Realce crop life cycle and compare its nutritional value with other commonly consumed varieties. Six treatments were performed: T0 - Control; T1 - Calmar® (soil - 100 kg/ha); T2 - Profertil® (foliar - 0.5%(v/v)); T3 - Albit® (leaf - 0.02%(v/v)); T4 - Calmar® ((100 kg/ha) + Profertil® (0.5%(v/v)); T5 - Calmar® ((100 kg/ha) + Albit® (0.02% (v/v)). The leaf chlorophyll index revealed significant increases for T2, T4 and T5, compared to control. In general, the treatments related to the pods morphology showed significant increases in the length/width ratio. In terms of productivity, significant increases were found with T1, T4 and T5. In the analysis of the nutritional value of dried beans there were significant increases in the contents of fiber in T1, protein in T4 and T5 and carbohydrates for T1, T2 and T3. For mineral composition, there were increases in the phosphorus content of T2, T4 and T5 beans. When the cooked beans were analysed, T4 and T1 produced a greater amount of ash and proteins, as compared to control. The applications of bio-inputs in the bean crop (Phaseolus vulgaris L.) exerted several positive and significant effects, mainly on the CCI, productivity, pod morphology as well as cooked bean nutritional values. It was verified that BRSMG Reakce has the potential to be included in the Portuguese diet.

Evaluation of irrigation frequency on pineapple plants grown in greenhouse conditions

• Seasons affect the values of all the indicators (LCI, NDVI, SDD, RWC). • The sensitivity of the non-destructive indicator is higher than the destructive. • High and medium irrigation frequency show higher conversion of water into biomass. • High frequency shows higher crop water productivity at the end of vegetative cycle. The objectives of this work are to evaluate the water status and growth variables of pineapple plants under different frequencies of irrigation to optimize the water productivity irrigation in greenhouse conditions in the subtropics. The experiment was conducted during the vegetative cycle for nine months, comparing three frequencies of irrigation: irrigation every three days (High frequency-T1), every seven days (Medium frequency-T2), and every 15 days (Low frequency-T3). The water status was measured using destructive indicators: Relative Water Content (RWC) and non-destructive indicators: Normalized Difference Vegetation Index (NDVI), Stress Degree Day (SDD), and Leaf Chlorophyll Index (LCI). Water productivity indicators (Irrigated water productivity, crop water productivity) and growth variables (plant height, maximum diameter, plant biomass, assimilate partitioning) were also measured. The environmental conditions monitored were temperature, humidity, and incident radiation. The soil moisture depletion and daily depletion rate were also registered and calculated. Destructive indicators of water status did not detect differences between irrigation treatments in this study, while non-destructive indicators statistically differentiated T1 from T3. T2 was the most appropriate irrigation treatment during the cold season. These results suggest that in greenhouse conditions in subtropical environments, a combination of high frequencies in warm seasons and medium frequencies in cold seasons would adjust irrigation management according to the pineapple crop needs, optimizing irrigation water productivity.