Flowering Stage Research Articles

Effects of LDPE and PBAT plastics on soil organic carbon and carbon-enzymes: A mesocosm experiment under field conditions

Although the effects of plastic residues on soil organic carbon (SOC) have been studied, variations in SOC and soil carbon-enzyme activities at different plant growth stages have been largely overlooked. There remains a knowledge gap on how various varieties of plastics affect SOC and carbon-enzyme activity dynamics during the different growing stages of plants. In this study, we conducted a mesocosm experiment under field conditions using low-density polyethylene and poly (butylene adipate-co-terephthalate) debris (LDPE-D and PBAT-D, 500–2000 μm (pieces), 0%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 2%), and low-density polyethylene microplastics (LDPE-M, 500–1000 μm (powder), 0%, 0.05%, 0.1%, 0.5%) to investigate SOC and C-enzyme activities (β-xylosidase, cellobiohydrolase, β-glucosidase) at the sowing, seedling, flowering and harvesting stages of soybean (Glycine Max). The results showed that SOC in the LDPE-D treatments significantly increased from the flowering to harvesting stage, by 12.69%–13.26% (p < 0.05), but significantly decreased in the 0.05% and 0.1% LDPE-M treatments from the sowing to seedling stage (p < 0.05). However, PBAT-D had no significant effect on SOC during the whole growing period. For C-enzyme activities, only LDPE-D treatments inhibited GH (17.22–38.56%), BG (46.7–66.53%) and CBH (13.19–23.16%), compared to treatment without plastic addition, from the flowering stage to harvesting stage. Meanwhile, C-enzyme activities and SOC responded nonmonotonically to plastic abundance and the impacts significantly varied among the growing stages, especially in treatments with PBAT-D (p < 0.05). These risks to soil organic carbon cycling are likely mediated by the effects of plastic contamination and degradation soil microbe. These effects are sensitive to plastic characteristics such as type, size, and shape, which, in turn, affect the biogeochemical and mechanical interactions involving plastic particles. Therefore, further research on the interactions between plastic degradation processes and the soil microbial community may provide better mechanistic understanding the effect of plastic contamination on soil organic carbon cycling.

Improving the physiological properties and yield of safflower by combining organic and chemical nitrogen in different irrigation cut-off conditions

The purpose of this work was to investigate how different nutrition systems (N0: 0:0, N1: 100:0, N2: 75:25, N3: 50:50, N4: 25:75, and N5: 0:100 kg ha−1 nitrogen from urea and organic fertilizer sources respectively) affect the physiological characteristics and yield of safflower (Carthamus tinctorius L.) under different irrigation regimes. These irrigation regimes include complete irrigation (S0), irrigation cut-off at stem elongation (S1), flowering and pollination (S2), and grain filling (S3) stages. The S1 irrigation level led to a decrease in Fv/Fm (5 %), relative water content (RWC) of the leaf (17 %), leaf total chlorophyll (22 %), and soluble proteins of the leaf (21 %) an increase in electrolyte leakage (33 %), carotenoids (43 %), proline content (42 %) and soluble sugars of the leaf (39 %) compared with S0 irrigation level. The safflower leaf showed increased Fv/Fm, RWC, total chlorophyll, and soluble proteins when organic fertilizer was used alone or in combination with chemical fertilizers under irrigation cut-off conditions. Additionally, the use of organic fertilizer resulted in a decrease in carotenoid content, proline content, and soluble sugars of the safflower leaf. The highest biological yield was obtained with S0 irrigation level (21.62 t ha−1) and N3 integrated nutrition system (21.93 t ha−1), respectively. The N3 and N2 nutrition systems increased the grain yield by 3.34 t ha−1 and 3.56 t ha−1 in 2015 and 2016, respectively. The greatest negative effect on biological yield was observed when irrigation was cut-off during the vegetative stage, while the most detrimental impact on grain yield occurred when irrigation was ceased during the flowering and pollination stages. Overall, the results indicated that N2 and N3 nutrition systems while implementing irrigation cut-off at various growth stages reduced the negative impact of water deficiency on plants. This leads to decreased production costs for stress-resistant osmolytes and, consequently, improved grain yield and biological yield.

OsRHS Negatively Regulates Rice Heat Tolerance at the Flowering Stage by Interacting With the HSP Protein cHSP70-4.

Heat stress at the flowering stage significantly impacts rice grain yield, yet the number of identified genes associated with rice heat tolerance at this crucial stage remains limited. This study focuses on elucidating the function of the heat-induced gene reduced heat stress tolerance 1 (OsRHS). Overexpression of OsRHS leads to reduced heat tolerance, while RNAi silencing or knockout of OsRHS enhances heat tolerance without compromising yield, as assessed by the seed setting rate. OsRHS is localized in the cytoplasm and mainly expressed in the glume and anther of spikelet. Moreover, OsRHS was found to interact with the HSP protein cHSP70-4, and the knockout of cHSP70-4 resulted in increased heat tolerance. Complementation assays revealed that the knockout of cHSP70-4 could restore the compromised heat tolerance in OsRHS overexpression plants. Additional investigation reveals that elevated temperatures can amplify the bond between OsRHS and cHSP70-4 within rice. Furthermore, our findings indicate that under heat stress conditions during the flowering stage, OsRHS plays a negative regulatory role in the expression of many stress-related genes. These findings unveil the crucial involvement of OsRHS and cHSP70-4 in modulating heat tolerance in rice and identify novel target genes for enhancing heat resilience during the flowering phase in rice.

FREQUENCY AND PATHOGENICITY OF Fusarium SPECIES IN WHEAT SPIKE: PRELIMINARY RESULTS

Wheat (Triticum aestivum) is a commercially important cereal in Mexico; however, there have been reports of head blight in Guanajuato, Mexico, which have been attributed to Fusarium species. This study hypothesized that wheat head blight is caused by several species of Fusarium. Therefore, the objective was to evaluate the frequency and pathogenicity of Fusarium species in wheat spike in the state of Guanajuato. For this purpose, plots sown with wheat in the 20 wheat-producing municipalities were sampled. The strains were isolated until pure cultures were obtained, and they were morphologically and molecularly characterized; the sequences obtained were registered in GenBank. The pathogenicity and severity of the disease were assessed on flowering wheat plants of the Cortázar S94 variety at the flowering stage. The results were evaluated 10 days after inoculation and the data were analyzed using ANOVA statistical analysis. Ten Fusarium species were found, with F. oxysporum (35.57 %), F. verticillioides (12.5 %), and F. proliferatum (11.53 %) being the most common. All Fusarium strains were pathogenic, with F. oxysporum being the most severe, followed by F. proliferatum. In conclusion, it was possible to identify the causal species of wheat head blight in the state of Guanajuato.

Individual and combined effects of high-temperature stress at booting and flowering stages on rice grain quality.

High temperature stress (HTS) has become a serious threat to rice grain quality and few studies have examined the effects of HTS across multiple stages on rice grain quality. In the present study, we conducted 2 years of HTS treatments under three temperature regimes (32/22 °C, 40/30 °C and 44/34 °C) and HTS durations of 2 days and 4 days at three critical stages: booting, flowering, and a combination of booting and flowering. We employed the heat degree days (HDD) metric, which accounts for both the level and duration of HTS, to quantify the relationships between grain quality traits and HTS. The results revealed the diverse effects of HTS on rice grain quality at different stages, durations and temperature levels. HTS significantly (P < 0.05) reduced grain quality, with the highest sensitivities (reduction per 1 °C day-1 increase in HDD) observed at the flowering stage, followed by the combined and booting stages treatments under mild HTS treatment (40/30 °C). However, under extreme HTS treatments (44/34 °C) for 4 days, rice grains subjected to combined HTS treatment experienced complete mortality. Pre-exposed to HTS at the booting stage within a certain intensity can alleviate the adverse effects of post-flowering HTS on grain quality. This provides valuable insights for assessing the potential impact of multiple HTS events on the grain quality under future climate warming. © 2024 Society of Chemical Industry.

Comparative chemometric modeling of fresh and dry cannabis inflorescences using FT-NIR spectroscopy: Quantification and classification insights.

Cannabis sativa L. inflorescences are rich in cannabinoids and terpenes. Traditional chemical analysis methods for cannabinoids and terpenes, such as liquid and gas chromatography (using UV or MS detectors), are expensive and time-consuming. This study explores the use of Fourier transform near-infrared (FT-NIR) spectroscopy combined with chemometric approaches for classifying cannabis chemovars and predicting cannabinoid and terpene concentrations for the first time in freshly harvested (wet) cannabis inflorescence. The study also compares the performance of FT-NIR spectroscopy on wet versus dry cannabis inflorescences. Spectral data from 187 samples across seven cannabis chemovars were analyzed using partial least squares-discriminant analysis (PLS-DA) and partial least squares-regression (PLS-R) models. The PLS-DA models effectively classified chemovars and major classes using only two latent variables (LVs) with minimal overfitting risk, with sensitivity, specificity, and accuracy values approaching 1. Despite the high water content in wet cannabis inflorescence, the PLS-R models demonstrated good to excellent predictive capabilities for nine cannabinoids and eight terpenes using FT-NIR spectra for the first time, achieving cross-validation and prediction R-squared values greater than 0.7, ratio of performance to interquartile range (RPIQ) exceeding 2, and a RMSECV/RMSEC ratio below 1.24. However, the low-cannabidiolic acid submodel and (-)-Δ9-trans-tetrahydrocannabinol model showed poor predictive performance. Some cannabinoid and terpene prediction models in wet cannabis inflorescence exhibited lower predictive capabilities compared with previously published models for dry cannabis inflorescence. These findings suggest that FT-NIR spectroscopy can be a viable rapid on-site analytical tool for growers during the inflorescence flowering stage.

Multi-omics analysis revealed the mechanism underlying flavonol biosynthesis during petal color formation in Camellia Nitidissima

BackgroundCamellia nitidissima is a rare, prized camellia species with golden-yellow flowers. It has a high ornamental, medicinal, and economic value. Previous studies have shown substantial flavonol accumulation in C. nitidissima petals during flower formation. However, the mechanisms underlying the golden flower formation in C. nitidissima remain largely unknown.ResultsWe performed an integrative analysis of the transcriptome, proteome, and metabolome of the petals at five flower developmental stages to construct the regulatory network underlying golden flower formation in C. nitidissima. Metabolome analysis revealed the presence of 323 flavonoids, and two flavonols, quercetin glycosides and kaempferol glycosides, were highly accumulated in the golden petals. Transcriptome and proteome sequencing suggested that the flavonol biosynthesis-related genes and proteins upregulated and the anthocyanin and proanthocyanidin biosynthesis-related genes and proteins downregulated in the golden petal stage. Further investigation revealed the involvement of MYBs and bHLHs in flavonoid biosynthesis. Expression analysis showed that flavonol synthase 2 (CnFLS2) was highly expressed in the petals, and its expression positively correlated with flavonol content at all flower developmental stages. Transient overexpression of CnFLS2 in the petals increased flavonol content. Furthermore, correlation analysis showed that the jasmonate (JA) pathways positively correlated with flavonol biosynthesis, and exogenous methyl jasmonate (MeJA) treatment promoted CnFLS2 expression and flavonol accumulation.ConclusionsOur findings showed that the JA-CnFLS2 module regulates flavonol biosynthesis during golden petal formation in C. nitidissima.

Exploring the Fermentation Products, Microbiology Communities, and Metabolites of Big-Bale Alfalfa Silage Prepared with/without Molasses and Lactobacillus rhamnosus

The influence of molasses (M) and Lactobacillus rhamnosus (LR) on fermentation products, microbial communities, and metabolites in big-bale alfalfa silage was investigated. Alfalfa (Medicago sativa L.) was harvested at the third growth stage during the flowering stage in the experimental field of Linhui Grass Company from Tongliao City, Inner Mongolia. An alfalfa sample without additives was used as a control (C). M (20 g/kg) and LR (106 cfu/g) were added either alone or in combination. Alfalfa was fermented for 7, 14, and 56 d. Lactic acid content in the M, LR, and MLR groups increased, whereas the pH value and butyric acid, 2,3-butanediol, and ethanol contents decreased compared to those of C group after 7, 14, and 56 d of fermentation. A two-way analysis of variance (ANOVA) was performed to estimate the results. The LR group exhibited increased Lactobacillus abundance, whereas the M and MLR groups showed increased Weissella abundance compared to the C group. The relative contents of amino acids (tyrosine, isoleucine, threonine, arginine, valine, and citrulline) in the M and MLR groups were higher than those in the C group. During fermentation, the M, LR, and MLR groups showed decreased phenylalanine, isoleucine, and ferulic acid contents. Amino acids such as isoleucine and L-aspartic acid were positively correlated with Lactobacillus but negatively correlated with Weissella. In conclusion, combining high-throughput sequencing and liquid chromatography–mass spectrometry during anaerobic alfalfa fermentation can reveal new microbial community compositions and metabolite profiles, supporting the application of M, LR, and MLR as feed fermentation agents.

Foliar spraying exogenous ABA resists chilling stress on adzuki beans (Vigna angularis).

Adzuki bean, an important legume crop, exhibits poor tolerance to low temperatures. To investigate the effect of exogenous abscisic acid (ABA) on the physiological metabolism and yield resistance of adzuki bean under low-temperature stress, we conducted a potted experiment using Longxiaodou 4 (LXD 4) and Tianjinhong (TJH) as test materials and pre-sprayed with exogenous ABA at flowering stage continuously for 5 days with an average of 12°C and an average of 15°C, respectively. We found that, compared with spraying water, foliar spraying exogenous ABA increased the activities of antioxidants and the content of non-enzymatic antioxidants, effectively inhibited the increase of malondialdehyde (MDA), hydrogen peroxide (H2O2) content, O2-· production rate. Exogenous ABA induced the activation of endogenous protective mechanisms by increasing antioxidant enzymes activities such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), as well as elevated levels of non-enzymatic antioxidants including ascorbic acid (ASA) and glutathione (GSH). Moreover, the yield loss of 5.81%-39.84% caused by chilling stress was alleviated by spraying ABA. In conclusion, foliar spraying exogenous ABA can reduce the negative effects of low-temperature stress on the yield of Adzuki beans, which is essential to ensure stable production of Adzuki beans under low-temperature conditions.

β values obtained by linear regression models of morpho-physiological and biochemical variables as novel drought stress estimators in Capsicum annuum varieties

Capsicum annuum varieties are highly sensitive to drought. Under water stress conditions, these can show yield losses of up to 70 %. Due to the above, this work proposes a novel approach to obtain estimators of drought stress based on linear regression models for morpho-physiological and biochemical variables in jalapeño pepper (C. annuum cv. jalapeno M), bell pepper (C. annuum cv. california wonder), and serrano pepper (C. annnuum cv. serrano tampiqueno). Jalapeno pepper plants were grown for 69 days under permanent water deficit conditions at 40, 60, 80 % and 100 % of field capacity (FC) (100 % FC as control). Throughout the crop cycle, we monitored the plant's height and weight, basal stem diameter, transpiration, photosynthesis, stomatal conductance, NDVI, and proline. This monitoring allowed us to obtain linear regression models from the accumulated values for these variables, from which the slope values (β) were used as estimators of drought stress using the interval estimation method, in the same way, this method was used to estimate water status in bell pepper and serrano pepper. For bell pepper, drought levels of 40, 60, 80 and 100 % FC were imposed for 12 days and serrano pepper 60 and 100 % FC for 63 days. The results showed that this method can be used to estimate drought stress in jalapeno pepper for all the irrigation levels through photosynthesis and NDVI and can be applied for bell pepper and serrano pepper using stem diameter and plant height, and in the case of serrano pepper, NDVI showed adequate results. Also, this work establishes the relationship between the jalapeno pepper responses (morpho-physiological and biochemical) to drought stress during vegetative, flowering, and fruiting stages through a Principal Component Analysis (PCA). The PCA found that interaction among morphological, physiological, and biochemical responses change concerning the phenological stage of the plant. The results suggested several direct and inverse relationships between the variables and showed that drought can be described by stomatal conductance during any phenological stage of the crop. In parallel, the proline content, NDVI and plant height can also describe drought stress during the vegetative and flowering stages. This research is the first to apply this methodology to drought stress estimation in jalapeno, bell pepper, and serrano pepper cultivation. The results could significantly contribute to precision agriculture, sensor development, and water management.

Agronomic Interventions for Alleviating Water Stress and Optimizing Productivity of Field Crops: A Review

Water scarcity is the most significant concern facing agriculture today. Agriculture currently utilizes more than 70% of the world's freshwater, with much of it lost through evaporation, leaching and runoff. Drought escape and drought tolerance are the two significant mechanisms for plant growth under water-stressed conditions. Drought, a primary abiotic factor, limits crop productivity. It is a climatic phenomenon characterized by a prolonged lack of rainfall, resulting in moisture loss from the soil and a lack of water potential in plant tissues. It prevents the crop from obtaining its potential yield and substantially reduces crop production. Field crop rely on rainfall and are vulnerable to unpredictable drought stress throughout their vegetative and reproductive growth cycle. Drought stress is typical during the flowering stage in mostly crops, resulting in lower yield when cultivated with scarce rainfall. It can be reduced through agronomic means, such as mulching, tillage, intercropping and nutrient management, as well as chemical measures, such as the use of soil additives herbal hydrogel (Gond katira), foliar spray of salicylic acid and potassium nitrate. Herbal hydrgel helps in reducing the effect of drought stress on plants while also promoting increased plant growth and opverall performance. Foliar application of salicylic acid boosted bioactive chemical synthesis in the presence of water deficiency. Potassium nitrate to enhance water uptake, promote longer pod length and improve drought tolerance in plants.

Field Efficacy of Insecticides for Management of Lepidopteran Pests in Cashew

Efficacy of different insecticides against lepidopteran pests of cashew were tested at Dr. YSRHU- Cashew Research Station, Bapatla, AICRP on Cashew during 2015-16 to 2021-22. Among the insecticides lamda-cyhalothrin 5 EC @ 0.6 ml/l was found effective in managing the foliage and floral pests such as, leaf and blossom webber, leaf miner, shoot tip caterpillar, apple and nut borer followed by Dr. YSR Horticultural University package of practices (POP) i.e. monocrotophos 36 SL @ 1.6 ml/l during the flushing stage, chlorpyrifos 20 EC @ 2.0 ml/l during the flowering stage and profenophos 50 EC @ 1.0 ml/l during the apple and nut development stage. Further, the spider population was observed to be highest in untreated check and Beauveria bassiana treatments compared to insecticidal treatments.

Interaction Effects of Water and Nitrogen Practices on Wheat Yield, Water and Nitrogen Productivity under Drip Fertigation in Northern China

Water resource shortage and unreasonable application of nitrogen (N) fertilizer have been problems in wheat production of northern China. However, the interaction effects of water regimes and N practices on wheat root growth, grain yield, soil water, and inorganic N changes as well as water-N use efficiency are still unclear under drip irrigation. A field experiment was conducted during the 2020–2021 and 2021–2022 winter wheat (Triticum aestivum) growing seasons. In this study, three irrigation schedules (i.e., irrigation was applied up to 80% [D1], 75% [D2], and 70% [D3] as soon as the soil water content decreased to 65%, 60% or 55% of field capacity) and two N practices (i.e., N applied at the base, jointing, booting stages were 90, 72, 48 kg ha−1 [N1], and the base, jointing, booting, filling stages were 90, 40, 40, 40 kg ha−1 [N2], respectively) were considered. The decease in irrigation water amount was offset by the increase in soil water consumption. In addition, N practices significantly interacted with irrigation on soil NO3−–N accumulation (2021–2022), NH4+–N accumulation, SPAD value (2020–2021), N content in stems and grains at maturity, and average root length and weight density at the flowering stage. Irrigation, rather than N practices, significantly affected grain yield, total N uptake, crop N transformations (NT), the contribution of NT to grain (NTPC), water and N productivity, in which, for the value of these two seasons, D2 increased total N uptake by 18.1% (p &lt; 0.05), and NT by 39.4% (p &lt; 0.05) under N1 as compared to D3. Additionally, the highest WUE and ANUE were found in D2 during 2021–2022. Heavy irrigation water amount caused high a LAI; further analysis proved that the LAI was the key factor affecting grain yield, and positively and significantly correlated to yield. However, no significant difference in the LAI between D1 and D2 was found. N1 was beneficial to prevent N leaching and increase water and N use efficiency, biomass, and N transformation amount. This study recommends that D2 + N1 might be a promising system for manipulating irrigation and fertilization practices under sub-surface drip irrigation systems to improve water and N use efficiency and grain yields in semi-arid regions.

Competition for nutrient niches within the apple blossom microbiota antagonizes the initiation of fire blight infection.

Changes in the plant microbiota composition are intimately associated with the health of the plant, but factors controlling the microbial community in flowers are poorly understood. In this study, we used apple flowers and fire blight as a model system to investigate the effects of floral microbiota and microbial competition on disease development and suppression. To compare changes in microbial flora with the RNA expression patterns of plants, the flower samples were collected in three different flowering stages (Bud, Popcorn, and Full-bloom). Using advanced sequencing technology, we analyzed the data and conducted both in vitro and in vivo experiments to validate our findings. Our results show that the Erwinia amylovora use arabinogalactan, which is secreted on the flowers, for early colonization of apple flowers. Pantoea agglomerans was more competitive for arabinogalactan than E. amylovora. Additionally, P. agglomerans suppressed the expression of virulence factors of E. amylovora by using arabinose, which is a major component of arabinogalactan, which induces virulence gene expression. The present data provide new insights into developing control strategies for diverse plant diseases, including fire blight, by highlighting the importance of nutrients in disease development or suppression.

Ca2+-induced CpCBL8-CpCIPK9 module negatively regulates dormancy breaking and cold tolerance in winter-flowering wintersweet

The complex of calcineurin B-like protein (CBL) and CBL-interacting protein kinase (CIPK) serves as key components in calcium-sensing, orchestrating various signals crucial for plant growth, development, and responses to biotic and abiotic stresses. However, the mechanism underlying the response of this module to cold stress and its role in flower development in wintersweet (Chimonanthus praecox) remains unclear. Through expression pattern analysis, calcium ion (Ca2+) concentration assays, correlation analysis, and linear regression analysis, we found that the [Ca2⁺], along with CpCBL8 and CpCIPK9 expression levels in wintersweet flower buds (FBs), significantly decreased during the initial flowering stage when the chilling requirement reached 570 chill units (CU). Notably, there was a significant positive correlation between [Ca2⁺] and CpCBL8 expression. Ca2+ increased the expression of CpCBL8 and CpCIPK9 in FBs, causing a significant delay in the flowering of wintersweet. Furthermore, the function of CpCBL8 was studied using heterologous transformation. Overexpression of CpCBL8 significantly delayed flowering time and significantly reduced cold tolerance and altered the expression pattern of endogenous genes related to low-temperature stress and flower development in transgenic Arabidopsis thaliana. Additionally, transcriptome analysis of chilling-induced dormancy breaking and flower bud enlargement revealed that CpCBL8 and CpCIPK9 were negatively regulated by cold, and the expression pattern of endogenous genes related to flower development and cold stress in wintersweet were similar to that of in A. thaliana. Moreover, protein–protein interaction (PPI) analysis revealed that CpCBL8 and CpCIPK9 interacted in the plasma membrane and nucleus. On the basis of these findings, we speculated that the CpCBL8-CpCIPK9 module plays a crucial role in regulating responses to cold stress and flower development in wintersweet. This study elucidated molecular mechanisms through which the downregulation of the Ca2+-induced CpCBL8-CpCIPK9 module results in dormancy breaking and enhances cold tolerance. This study provides valuable insights for the cultivation of new varieties of wintersweet with increased ornamental value and enhanced cold stress tolerance.

Combined inoculation of arbuscular mycorrhiza fungi with Meso‐rhizobium improves nutrient uptake, growth performance, and moisture stress tolerance of chickpea (Cicer arietinum L.)

AbstractBiofertilizers can be better alternatives to chemical fertilizers to enhance plant nutrition and productivity as they improve the soil fertility and crop productivity in an eco‐friendly and cost‐effective manner. A pot experiment was conducted between December 2018 and March 2019 in southern Ethiopia to evaluate the combined inoculation of arbuscular mycorrhizal fungi (AMF) and Meso‐rhizobium (MR) on biomass yield, nutrient uptake, and moisture stress tolerance of chickpea (Cicer arietinum L.) (variety: Habru). The experiment was executed as a factorial arrangement using a completely randomized design with three replications. The treatments were control (non‐fertilized), sole AM fungi inoculation, AM fungi inoculation with phosphorus fertilizer (20 kg P ha−1) and MR, and sole inorganic fertilizers (20 kg P;10 kg N ha−1) at four different moisture levels (optimum throughout the growing season, stressed at vegetative, flowering, and seed filling stages). The results demonstrated that biomass yields were limited by moisture stress, especially at vegetative and flowering stages of chickpea. Sole and co‐application of AMF with MR and inorganic P increased biomass yields on average by 19%, 39%, and 33% under water stress conditions, respectively, compared to the non‐inoculated control. The application of AMF with MR and inorganic P also significantly increased nodulation, AMF colonization, and nutrient uptake, but these effects were dependent on soil moisture status. In conclusion, there are potential advantages to be gained from sole and combined AMF application with rhizobium to improve growth and productivity of chickpea through enhanced nutrient and water uptake, though the results of this pot experiment should be validated through field trials.

Estimating Leaf Area Index in Apple Orchard by UAV Multispectral Images with Spectral and Texture Information

The Leaf Area Index (LAI) strongly influences vegetation evapotranspiration and photosynthesis rates. Timely and accurately estimating the LAI is crucial for monitoring vegetation growth. The unmanned aerial vehicle (UAV) multispectral digital camera platform has been proven to be an effective tool for this purpose. Currently, most remote sensing estimations of LAIs focus on cereal crops, with limited research on economic crops such as apples. In this study, a method for estimating the LAI of an apple orchard by extracting spectral and texture information from UAV multispectral images was proposed. Specifically, field measurements were conducted to collect LAI data for 108 sample points during the final flowering (FF), fruit setting (FS), and fruit expansion (FE) stages of apple growth in 2023. Concurrently, UAV multispectral images were obtained to extract spectral and texture information (Gabor transform). The Support Vector Regression Recursive Feature Elimination (SVR-REF) was employed to select optimal features as inputs for constructing models to estimate the LAI. Finally, the optimal model was used for LAI mapping. The results indicate that integrating spectral and texture information effectively enhances the accuracy of LAI estimation, with the relative prediction deviation (RPD) for all models being greater than 2. The Categorical Boosting (CatBoost) model established for FF exhibits the highest accuracy, with a validation set R2, root mean square error (RMSE), and RPD of 0.867, 0.203, and 2.482, respectively. UAV multispectral imagery proves to be valuable in estimating apple orchard LAIs, offering real-time monitoring of apple growth and providing a scientific basis for orchard management.

Monitoring Soybean Soil Moisture Content Based on UAV Multispectral and Thermal-Infrared Remote-Sensing Information Fusion.

By integrating the thermal characteristics from thermal-infrared remote sensing with the physiological and structural information of vegetation revealed by multispectral remote sensing, a more comprehensive assessment of the crop soil-moisture-status response can be achieved. In this study, multispectral and thermal-infrared remote-sensing data, along with soil-moisture-content (SMC) samples (0~20 cm, 20~40 cm, and 40~60 cm soil layers), were collected during the flowering stage of soybean. Data sources included vegetation indices, texture features, texture indices, and thermal-infrared vegetation indices. Spectral parameters with a significant correlation level (p < 0.01) were selected and input into the model as single- and fuse-input variables. Three machine learning methods, eXtreme Gradient Boosting (XGBoost), Random Forest (RF), and Genetic Algorithm-optimized Backpropagation Neural Network (GA-BP), were utilized to construct prediction models for soybean SMC based on the fusion of UAV multispectral and thermal-infrared remote-sensing information. The results indicated that among the single-input variables, the vegetation indices (VIs) derived from multispectral sensors had the optimal accuracy for monitoring SMC in different soil layers under soybean cultivation. The prediction accuracy was the lowest when using single-texture information, while the combination of texture feature values into new texture indices significantly improved the performance of estimating SMC. The fusion of vegetation indices (VIs), texture indices (TIs), and thermal-infrared vegetation indices (TVIs) provided a better prediction of soybean SMC. The optimal prediction model for SMC in different soil layers under soybean cultivation was constructed based on the input combination of VIs + TIs + TVIs, and XGBoost was identified as the preferred method for soybean SMC monitoring and modeling, with its R2 = 0.780, RMSE = 0.437%, and MRE = 1.667% in predicting 0~20 cm SMC. In summary, the fusion of UAV multispectral and thermal-infrared remote-sensing information has good application value in predicting SMC in different soil layers under soybean cultivation. This study can provide technical support for precise management of soybean soil moisture status using the UAV platform.

Biomass Accumulation, Soil Fertility and Energy Use in Seed Crop Systems of Velvet Bean (Mucuna Pruriens L.)

ABSTRACT Seed crop production systems of velvet bean (Mucuna pruriens L.) were assessed in two field studies for ecosystem services. At flowering stage, long duration genotype Arka Shubra was significantly superior in biomass accumulation (14.61 t ha−1), while 100% recommended NPK + 15 t FYM ha−1 registered significantly higher biomass production (11.74 t ha−1). Biomass availability at harvest was higher in long duration genotypes (7.48–7.75 t ha−1) and the average biomass availability of 6.45 t ha−1 at harvest gives scope for including velvet bean as component crop in cropping systems/fallows. The average soil carbon stocks were estimated at 22.8 t ha−1 at the end of 2 yrs and 12.4 t ha−1 at the end of one crop season. Soil nutrient availability was optimum except for soil test P in pre-, standing and post crop growth periods. Highly significant relations (R 2 = 0.949) were observed between nodule number and available N at harvest. The N availability was more in long duration genotypes (209–215 kg N ha−1) over pre-experimental status. Nutrient addition improved the available N status by 40–185 kg ha−1 over pre-experimental status and control. The nutrient uptake was 4–10% higher in Arka Shubra over other long duration genotypes and 100–200% higher over medium/short duration genotypes at flowering. The recyclable biomass and uptake of NPK are more in long duration genotypes implying huge nutrient recycling potential of the system. Overall, seed crop systems of velvet bean are efficient in resource use and energy use (>2.5 EUE) and ideal components for sustainable land management.

Optimizing nutrient sources for quality bulb and bulblet production in LA hybrid lilium: A study in the North Indian plains.

LA hybrid lilium cv. ‘Masai’ bulbs were grown over two consecutive growth seasons in a net house to enhance the yield of high-quality bulbs and bulblets, utilizing both organic and inorganic nutrients. The experiment tested five levels of organic manure (FYM) (0, 10, 15, 20, and 25 t ha-1) and inorganic fertilizers (0, 40+30+25, 80+60+50, 120+90+75, and 160+120+100 N+P2O5+K2O kg ha-1). It assessed both individual and combined effects of nutrient sources, concluding that their combined application was most beneficial. Treatment T24, comprising 25 t FYM with 160 kg N, 120 kg P2O5, and 100 kg K2O ha-1, proved to be the most effective. The study revealed that treatment T24 resulted in the largest bulb circumference, the highest number of bulblets per plant, the greatest bulblet circumference, and the highest fresh and dry weights of both bulbs and bulblets per plant. It also led to the best relative growth rate (RGR) of the bulb, as well as the most efficient partitioning rates at both the flowering and harvest stages. Treatment T23 notably influenced the fresh and dry weights of the bulblets. The data suggest that T24 produces bulbs and bulblets of superior quality compared to other treatments, making it a viable choice for the commercial cultivation of quality LA hybrid lilium bulbs and bulblets in the plains of India.