Maturity Date Research Articles

Pricing of timer volatility-barrier options under Heston’s stochastic volatility model

Timer options are financial instruments that enable investors to exercise their rights on a random maturity date the realized variance reaches the level of variance budget. These options provide a stable investment opportunity for investors under the unpredictable and complex financial markets, such as global financial crisis or COVID-19 pandemic, which can induce the drastic changes of the volatility for the underlying asset. Meanwhile, in the financial markets, investors who invest in standard timer options may face the problems caused by the postponement of the exercising time for too low volatility, compared to standard vanilla options. In this regard, to overcome such disadvantages, we propose timer volatility-barrier options, which are activated and expired when the volatility arrives at a relatively low barrier level, with the original properties of the standard timer options. In this paper, by making use of the method of images, we derive an analytical formulas for the timer volatility-barrier options so that the volatility process can be driven by Heston stochastic volatility model, and verify the pricing accuracy of the timer options by comparing our solutions with those obtained from Monte Carlo simulations. Finally, we conduct numerical studies on the timer volatility-barrier options to examine the pricing sensitivities with respect to the various model parameters, and implement the discussion for pricing formula of double volatility barrier type of the timer options.

Determination of the Effects of Aminoethoxyvinilglycine (AVG) and Gibberellic Acid (GA3) Applications on Pre-Harvest Fruit Drop Amount and Fruit Quality in Hakko Pear Cultivar

This study was conducted to determine the effects of pre-harvest Aminoethoxyvinylgylcine (AVG) and Gibberellic acid (GA3) applications on the pre-harvest fruit drop amount and fruit quality in the 'Hakko' pear (Pyrus pyrifolia) cultivar grafted on BA29 rootstock in a private orchard in the Bala district of Ankara in 2021-2022. It was conducted in an orchard belonging to a producer. 50-100-150 mg/l AVG and 25-50-75 mg/l GA3 were applied 4 weeks before the estimated harvest date. Fruits are harvested at full maturity date; Pomological properties such as cumulative drop percentage, yield, fruit weight, fruit width and length, fruit stem width and length, fruit flesh firmness, fruit color, and chemical properties such as soluble solids content (SSC), pH and titratable acidity (TA) were evaluated. It was observed that all doses of AVG and GA3 during the harvest period reduced the cumulative casting rate compared to the control application (6.78%). In general, the yield per tree was found to be high in GA3 applications. In both AVG and GA3 applications, its effects on fruit weight, fruit width and length, fruit flesh firmness, SSC and pH were found to be statistically significant. It was observed that in both AVG and GA3 applications, the amount of fruit drop pre-harvest decreased and fruit quality characteristics were better than the control.

Plant-Parasitic Nematode Genera Associated with Date Palm in Central Iraq

A survey of plant-parasitic nematode genera associated with roots of mature date palm trees was conducted in central Iraq to study the occurrence, population density and geographical distribution. This study in Baghdad, Babil, Diyala, Karbela, Najaf, and Wasit governorates was conducted from 2019 to 2023, during the months from October to April. A total of 150 soil and root samples were gathered from 46 fields, and plant parasitic nematodes were extracted and morphologically identified to genus level. Eleven genera of plant parasitic nematodes were detected in the declining order of frequency: Tylenchorhynchus spp. (20%) in Baghdad, Babil, Diyala, Karbala, and Najaf; Meloidogyne spp., (17.3%) in Baghdad, Babil, Diyala, Najaf, and Wasit; Paratylenchus spp. (16%) in Diyala and Najaf; Helicotylenchus spp. (12%) in Baghdad, Diyala, Najaf, and Wasit; Tylenchus spp. (12%) in Baghdad, Babil, Diyala, Najaf, and Wasit; Aphelenchoides spp. (6.7%) in Babil, Diyala, Karbala, and Wasit; Pratylenchus spp. (4%) in Baghdad, Diyala, Najaf, and Wasit; Ditylenchus spp. (3.3%) in Babil and Najaf; Hoplolaimus spp. (1.3%) in Diyala; and Heterodera spp. and Scutellonema spp. (0.7% each) in Diyala. Population density was low in Baghdad. High population density was recorded for Meloidogyne spp., (37625 J2 /1000 cm3 soil) and lowest population density occurred with Paratylenchus spp. (20 nematodes /1000 cm3 soil) in Diyala (Al-Jadidah). This appears to be the first report of occurrences of plant-parasitic nematodes of date palm in central Iraq.

Identification of Quantitative Trait Loci Associated with Plant Adaptation Traits Using Nested Association Mapping Population.

This study evaluated 290 recombinant inbred lines (RILs) of the nested association mapping (NAM) population from the UK. The population derived from 24 families, where a common parent was "Paragon," one of the UK's spring wheat cultivar standards. All genotypes were tested in two regions of Kazakhstan at the Kazakh Research Institute of Agriculture and Plant Industry (KRIAPI, Almaty region, Southeast Kazakhstan, 2019-2022 years) and Alexandr Barayev Scientific-Production Center for Grain Farming (SPCGF, Shortandy, Akmola region, Northern Kazakhstan, 2019-2022 years). The studied traits consisted of plant adaptation-related traits, including heading date (HD, days), seed maturation date (SMD, days), plant height (PH, cm), and peduncle length (PL, cm). In addition, the yield per m2 was analyzed in both regions. Based on a field evaluation of the population in northern and southeastern Kazakhstan and using 10,448 polymorphic SNP (single-nucleotide polymorphism) markers, the genome-wide association study (GWAS) allowed for detecting 74 QTLs in four studied agronomic traits (HD, SMD, PH, and PL). The literature survey suggested that 16 of the 74 QTLs identified in our study had also been detected in previous QTL mapping studies and GWASs for all studied traits. The results will be used for further studies related to the adaptation and productivity of wheat in breeding projects for higher grain productivity.

Heading and maturity date prediction using vegetation indices: A case study using bread wheat, barley and oat crops

Contemporary crop research programs involve the evaluation of numerous micro-plots spread across extensive experimental fields. As a result, there is a growing need to depart from labor-intensive manual measurements when assessing phenological data. The growing significance of high throughput phenotyping platforms (HTTP), including unmanned aerial vehicles (UAVs), has rendered these technologies essential in crop research. The overall objective of this study is to explore and validate the use of HTTP methodologies, specifically the potential of vegetation indices (VIs) derived from conventional RGB images, to forecast the date of heading (DH) and maturity (DM) for various cereal crops under different irrigation conditions. To pinpoint DH and DM prediction, a total of nine UAV surveys were conducted throughout the entire crop cycle. Prediction models for DH and DM using VIs were successfully developed for various crop species, explaining 65 % of the variance in bread wheat and 75 % in oats. The highest percentages of variance explained were achieved when models were developed separately for the two irrigation conditions (well-irrigated and rainfed). However, the percentage of variance explained by these models decreased when applied to barley (R²<0.5 for DH). Notably, including final plant height as a predictor increased the percentage of variance explained by the models only for irrigated bread wheat. Furthermore, the utilization of multi-temporal equations, which amalgamated data from diverse UAV surveys, notably enhanced the percentage of variance explained by the model (+160.71 % improvement in DH predictions), particularly those tailored to each specific crop species and irrigation condition. The investigation additionally established a thorough protocol for modeling the phenological aspects of cereal crops utilizing data acquired from UAVs, thereby enhancing the accessibility of this technology for measurements of phenology in large crop research programs.

A novel mathematical method to estimate rice phenological parameters across spatial scales for the ORYZA model

While crop models are increasingly applied to large-scale areas, inadequate observation data make it difficult to calibrate the model’s phenological parameters at the regional scale. The present study proposed a simple mathematical method for estimating rice phenological parameters across spatial scales for the ORYZA model. The method establishes the cumulative function of the phenological parameters (CFPP). By fitting the CFPP with the so-called growth curve, the 4 phenological parameters of the ORYZA model were transformed into 3 fitted parameters in the equation of CFPP. Functions between the fitted parameters and several meteorological and field management factors were established. These established functions were substituted back into CFPP to construct a modified CFPP. Due to the inter-translational relationship between CFPP and the original phenological parameters, the values of phenological parameters could be estimated by the modified CFPP based on meteorological and field management factors. The newly proposed mathematical method was applied in the Yangtze River Basin (YRB), China. The results indicated that the multi-station average of the absolute value of relative errors for the rice panicle initiation, flowering, and maturity dates within the YRB were 12.3 %, 10.5 %, and 8.7 %, respectively, which were at most 4.8 % larger than that simulated using parameters calibrated using each station’s phenological data. The phenological parameters estimated by the novel mathematical method had close performance to those calibrated directly based on observed data at most stations in terms of rice phenology simulation. The present study provided a new solution for phenological parameter calibration for crop models when applied in a large-scale area.

Improving the estimation accuracy of wheat maturity date by coupling WheatGrow with satellite images

Accurate estimation of wheat maturity date (MD) is helpful to make reasonable harvest planning and guarantee crop yield and quality. In this study, wheat phenology extracted from satellite images was assimilated into WheatGrow model to develop wheat maturity date estimation model. Theoretical uncertainty was introduced into assimilation system as the error covariance matrix of remote sensing observations, which improved the performance of maturity date estimation model. Compared with the simulated maturity date of crop growth model and assimilation system combined with the constant uncertainty (Assimilation1), the accuracy of assimilation system combined with the theoretical uncertainty (Assimilation2) was higher (r = 0.81, RMSE = 4.5 d). Assimilation2 has better performance and robustness in different years and different subregions. The mean relative errors between the estimated values of Assimilation2 and the observations were generally small and concentrated in the range of −5 % to 5 %. The estimated maturity date showed latitude variation in spatial distribution in the Huang-Huai-Hai Plain (HHHP). In addition, the trend of wheat maturity date from 2001 to 2020 in the central region of HHHP was significant (p < 0.05), and the mean change rate of maturity date reached 3–6 d/10a. However, the overall change trend of maturity date in the HHHP was not significant. Temperature was main driver affecting the spatiotemporal variation of wheat maturity date. The regional wheat maturity date estimation model can provide technical support for wheat maturity date estimation at regional scale.

Sustainable and responsible investment (SRI) Sukuk: lessons from Khazanah’s Sukuk Ihsan

Purpose SRI Sukuk, with its outcome-based emphasis, aims to align the Islamic finance industry with its original ideals and address criticisms related to form over substance. In Malaysia, while the pioneering Sukuk Ihsan was a “social” sukuk, recent SRI Sukuk issuances have predominantly been “green” or “sustainable” sukuk. This paper aims to evaluate the Malaysian SRI Sukuk market, identifying factors favouring “green” sukuk. It also examines whether structural issues in Sukuk Ihsan deterred subsequent issuers from “social” sukuk. The emergence of SRI Sukuk responds to sustainable development goals and the shift towards a low-carbon economy. Sukuk Ihsan, as the first Shariah-compliant pay-for-success structure, poses complexity and risk management challenges to meet performance criteria. Design/methodology/approach The study used a qualitative method in the form of a critical review of literature, interview sessions with experts and stakeholders who are familiar with SRI Sukuk and Sukuk Ihsan and a case study analysis of Sukuk Ihsan. Findings The popularity of “green” sukuk reflects the growing global environmental consciousness. The main factors driving the popularity of “green” sukuk are the maturity of the market and the existence of a strong supporting infrastructure for “green” issuances while the positive profiling benefits and availability of incentives for “green” issuances also contribute to a lesser extent. The recommendations include the promotion of “social” sukuk by regulators through a focus on establishing a similar supporting infrastructure for “social” sukuk as there are for SRI and standard Sukuk. In addition, issuers of “social” sukuk may want to reconsider the inclusion of key performance indicators (“KPI”) into the structure of future “social” sukuk issuances. Research limitations/implications Although all respondents considered Sukuk Ihsan to be a success, some potential areas of improvement were also noted. These include the structuring of future “social” sukuk issuances with a bigger discount to compensate for the additional risk being assumed by the investor; the need to be more careful in the KPI selection process; and one respondent even went so far as to suggest the possibility of totally removing the step-down feature of Sukuk Ihsan. Practical implications Industry implications of Sukuk Ihsan study include findings that require balancing disclosure and economics by providing additional disclosure requirements for SRI Sukuk that may pose risks without corresponding benefits for issuers. KPI selection and investor confidence should also be properly identified, as KPIs are essential for the pay-for-success model to work successfully. For sukuk holders, findings indicate that any approval for waivers during issuance can impact investor confidence negatively. Investor literacy and impact understanding should also be improved for social Sukuk success. Investors should understand the different risk exposures and evolving impact requirements vital for sustainable growth. Social implications The findings provide significant implications for social impact Sukuk issuance. They include providing a substantial case study for future social impact issuances, based on the pioneering impact of Sukuk Ihsan. Furthermore, Sukuk Ihsan’s unqualified success validates the feasibility of socially responsible sukuk. Despite its early introduction, both tranches being fully subscribed reflects robust investor interest. Stakeholders were also proud of their involvement in such an initiative, viewing it as a significant achievement in creating societal impact. Originality/value Although there have been several prior studies done on Sukuk Ihsan, the focus of those studies was on its structure and the novelty of its “step down” returns structure where investors would receive lower returns if certain key performance indicators (“KPIs”) are met by Yayasan AMIR in the execution of its Trust School Programme. Bearing in mind that the first Sukuk Ihsan has a June 2022 maturity date, and the results of its KPIs were announced in December 2021, to the best of the authors’ knowledge, this is the only documented case study that comprehensively reviews Sukuk Ihsan and identifies lessons learned and/or opportunities for improvement for the benefit of potential SRI Sukuk issuers in the future.

Accumulated thermal units method for predicting development stages, and potential seed yield of sunflower (Helianthus annuus) under Mediterranean conditions

The possibility of accurately assessing the emergence, anthesis and maturation dates of sunflower grown under Mediterranean conditions was investigated. Accumulated Thermal Units (TSUM) from sowing to emergence, from emergence to anthesis, and from anthesis to maturation were recorded in 14 experimental sunflower plantations, carried out in two sites with representative soils in the Thessaly Plain (central Greece) in the years 2012, 2013, 2014, 2015 and 2022. Various combinations of sowing date; irrigation and N-fertilization inputs were studied, and the corresponding phenological stages and seed yields were determined. It was found that the TSUM method is very effective for predicting the duration of the phenological stages of sunflower and thus the development rate and stages of this crop. Particularly accurate is the assessment of the emergence-anthesis period calculated at 817 degree days (°C-d) for base temperature (To) equal to 6 °C and optimum temperature (Topt) 28 °C, whereas for the anthesis-maturation period, the TSUM method needs to be adjusted for photoperiodism, using a photoperiod coefficient based on the daylength. In a simpler approach, the heat unit sum of 1213°C-d (To=0 °C) it can be used for the emergence-anthesis period (or 1418°C-d for the sowing-anthesis period), without much error, and an average period of 44 days for the anthesis-maturation period. Having determined the anthesis-maturation period, the potential seed yield of sunflower was successfully assessed, based on the global radiation prevailing during the grain filling period (i.e. last 37 days before capitulum ripening) for the treatments of optimum water and nitrogen applications. Knowledge of the seed yield potential of sunflower might be very important for land evaluation purposes and the introduction of this important crop in Thessaly more generally and many Mediterranean sites.

Predicting rice phenology across China by integrating crop phenology model and machine learning

This study explores the integration of crop phenology models and machine learning approaches for predicting rice phenology across China, to gain a deeper understanding of rice phenology prediction. Multiple approaches were used to predict heading and maturity dates at 337 locations across the main rice growing regions of China from 1981 to 2020, including crop phenology model, machine learning and hybrid model that integrate both approaches. Furthermore, an interpretable machine learning (IML) using SHapley Additive exPlanation (SHAP) was employed to elucidate influence of climatic and varietal factors on uncertainty in crop phenology model predictions. Overall, the hybrid model demonstrated a high accuracy in predicting rice phenology, followed by machine learning and crop phenology models. The best hybrid model, based on a serial structure and the eXtreme Gradient Boosting (XGBoost) algorithm, achieved a root mean square error (RMSE) of 4.65 and 5.72 days and coefficient of determination (R2) values of 0.93 and 0.9 for heading and maturity predictions, respectively. SHAP analysis revealed temperature to be the most influential climate variable affecting phenology predictions, particularly under extreme temperature conditions, while rainfall and solar radiation were found to be less influential. The analysis also highlighted the variable importance of climate across different phenological stages, rice cultivation patterns, and geographic regions, underscoring the notable regionality. The study proposed that a hybrid model using an IML approach would not only improve the accuracy of prediction but also offer a robust framework for leveraging data-driven in crop modeling, providing a valuable tool for refining and advancing the modeling process in rice.

Exploring Genetic Variability and Morpho-Agronomic Trait Associations Among Ethiopian Flax (Linum Usitatissimum L.) Accessions for Enhanced Fiber and Seed Yield

ABSTRACT Flax is a versatile crop grown for its fiber and seed oil. Despite extensive conservation efforts in Ethiopia, the genetic potential of flax accessions conserved in the gene bank remains largely underexplored for fiber and seed yield. Here, we aimed to assess the genetic variability and association of morpho-agronomic traits and identify potential accessions for fiber and seed yield among 150 flax accessions. The study was conducted at Holeta Agricultural Research Center during 2022/23 growing season using an augmented design. Data were collected on flowering and maturity dates, plant and technical height, basal and secondary branch, boll and seed numbers, 1000-seed weight, and yield. Results revealed significant variation both between blocks and within treatments, with flowering time, maturity, plant height, boll number, seed weight, and yield contributing for the highest variability (58.7%). Cluster analysis revealed nine distinct genetic groups, each exhibiting specific trait patterns. Seed yield had strong associations with maturity, plant height, and boll number. High broad-sense heritability for days to flowering, plant height, and yield traits suggests selection could be effective based on phenotypic expressions. The study highlights the potential of Ethiopian flax genetic diversity for enhancing fiber and seed yield, suggesting effective selection based on key traits.

Solid bitumen Rhenium-Osmium (Re–Os) isotope geochronology and existing problems: Sampled of Sinian-Cambrian gas reservoir in Sichuan Basin, China

Understanding the key timings related to petroleum evolution is crucial for optimizing exploration targets and assessing oil/gas resources, attract petroleum geologists’ attention worldwide. Recently, hydrocarbon (oil and bitumen) Re–Os isotope dating has been innovatively applied to constrain the timing related to oil/gas generation, however, the resulting Re–Os isochron ages can be complex and challenging to interpret. This study utilizes various geochemical and geochronological data from Sinian to Cambrian natural gas reservoirs in the Sichuan Basin to reconstruct the hydrocarbon evolution process and discuss the significance of different bitumen Re–Os dating results. The gas accumulation in the Sinian-Cambrian reservoirs experienced four stages of evolution: (1) initial oil generation during the Ordovician to Silurian periods, (2) secondary oil generation during the Triassic period, (3) gas generation through thermal cracking of liquid oil from the Jurassic to Cretaceous periods, and (4) gas reservoir redistribution since the late Cretaceous. The Re–Os dates (ca. 485 Ma) of low maturity and biodegraded bitumen from the western Sichuan Basin record the oil generation during the Ordovician before the Caledonian tectonic event. The Re–Os dates (ca.184–128 Ma) of highly mature bitumen associated with MVT Pb–Zn deposits in northern Sichuan Basin provide insights into both liquid oil-cracking and thermochemical sulfate reduction (TSR) processes. The complex Re–Os dates (ca.414 Ma, ca.154 Ma) of highly mature bitumen from the central Sichuan Basin may represent different periods related to either oil or gas generation. Future studies should explore the genetic type, maturity, thermal cracking, or TSR degrees of bitumen to better understand the significance of Re–Os dates.

Physiological Maturity and Harvesting Date on Seed Yield and Quality of Indigo (Indigofera suffruticosa Mill.)

Background: Indigo is used to dye many fabrics, which also needs a lot of indigo plants enough to dye the fabric. Indigo seeds were used for propagation, but the seed of indigo is not simultaneous. The physiological maturity and optimum harvesting date affected the yield and quality of indigo seeds. This research aims to study the physiological maturity and harvesting date of indigo on seed yield and quality. Methods: Indigo plants were grown in the dry season. The experiment was a randomized complete block design (RCBD) with 4 replications, consisting of 4 harvesting dates; 140, 150, 160 and 170 days after planting (DAP). Result: The results showed that the first indigo flower was at 51 DAP and matured to pods at 59 DAP. It takes 113 DAP for the indigo color to change from green to brown. The appearance of the pods changed from green to yellowish green, brown and black, respectively. As the indigo pods became 50% brown, they started harvesting. The weights of a dry pod, a fresh pod and a seed were different. When harvesting at 140 DAP, the fresh pod weight had the maximum of 82.60 g/plant and dropped as the indigo harvesting date grew (P less than 0.01). The dry pod weight was the lowest, at 27.58 g/plant (P less than 0.05). The seed weight per plant for harvesting at 170 DAP was 25.57 g. The harvesting date, however, did not differ statistically. The highest percentage of germination and vigor were from the indigo seeds, which were harvested at 140 DAP, 31.94% and 38.81%, respectively (P less than 0.01). Therefore, the optimum harvesting date at 140 DAP is the physiological maturity stage and harvesting of the pods when they turn brown for the highest seed quality.

Changes in the leaf area-seed yield relationship in soybean driven by genetic, management and environments: Implications for High-Throughput Phenotyping

Abstract High-throughput crop phenotyping (HTP) in soybean [Glycine max L. (Merr.)] has been used to estimate seed yield with varying degrees of accuracy. Research in this area typically makes use of different machine learning approaches to predict seed yield based on crop images with a strong focus on analytics. On the other hand, a significant part of the soybean breeding community still utilizes linear approaches to relate canopy traits and seed yield relying on parsimony. Our research attempted to address the limitations related to interpretability, scope and system comprehension inherent in previous modelling approaches. We utilized a combination of empirical and simulated data to augment the experimental footprint as well as to explore the combined effects of genetics (G), environments (E) and management (M). We use flexible functions without assuming a pre-determined response between canopy traits and seed yield. Factors such as soybean maturity date, duration of vegetative and reproductive periods, harvest index (HI), potential leaf size, planting date and plant population affected the shape of the canopy-seed yield relationship as well as the canopy optimum values at which selection of high yielding genotypes should be conducted. This work demonstrates that there are avenues for improved application of HTP in soybean breeding programs if similar modelling approaches are considered.

The Impact of The Sovereign Credit Rating on The Possibility of Financing External Loans to The Iraqi Economy

External loans are a source of credit revenue. The process of obtaining it requires determining the degree of credit risk by predicting the financial solvency of the economy to judge its financial ability to pay the principal and interest dues of the loan at the specified maturity date. Considering that ability is a determinant of the creditworthiness of his economy, the extent to which financing can continue with this external credit source and its cost. The government of Iraq faced the difficulty of financing external loans from the international capital markets with its high return due to the lack of a sovereign credit rating that measures the risk of default through a process to determine the degree of that risk for investors of external lending funds. Therefore, the research came to show the effect of determining the sovereign credit rating on the extent to which the Government of Iraq can finance foreign loans, whether from capital markets or foreign governments and the impact of this classification on the credit facilities granted. The research concluded that the economy of Iraq got a sovereign credit rating within the degree of creditworthiness according to the classification of speculation to reflect the possibility of default in payment due to the dependence of the financial solvency of its economy on oil revenues, as the credit risks rise due to the inability to pay in the event of a decline in prices in the foreign market. However, relative stability within the short term enabled the Iraqi government to obtain foreign loans, with the requirement that Iraq provide guarantees by foreign governments and institutions in exchange for this source of credit.

Molecular selection of soybean towards adaptation to Central European agroclimatic conditions.

Europe is highly dependent on soybean meal imports and anticipates an increase of domestic plant protein production. Ongoing climate change resulted in northward shift of plant hardiness zones, enabling spring-sowing of freezing-sensitive crops, including soybean. However, it requires efficient reselection of germplasm adapted to relatively short growing season and long-day photoperiod. In the present study, a PCR array has been implemented, targeting early maturity (E1-E4, E7, E9, and E10), pod shattering (qPHD1), and growth determination (Dt1) genes. This array was optimized for routine screening of soybean diversity panel (204 accessions), subjected to the 2018-2020 survey of phenology, morphology, and yield-related traits in a potential cultivation region in Poland. High broad-sense heritability (0.84-0.88) was observed for plant height, thousand grain weight, maturity date, and the first pod height. Significant positive correlations were identified between the number of seeds and pods per plant, between these two traits and seed yield per plant as well as between flowering, maturity, plant height, and first pod height. PCR array genotyping revealed high genetic diversity, yielding 98 allelic combinations. The most remarkable correlations were identified between flowering and E7 or E1, between maturity and E4 or E7 and between plant height and Dt1 or E4. The study demonstrated high applicability of this PCR array for molecular selection of soybean towards adaptation to Central Europe, designating recessive qPHD1 and dominant Dt1, E3, and E4 alleles as major targets to align soybean growth season requirements with the length of the frost-free period, improve plant performance, and increase yield.

The simultaneous prediction of yield and maturity date for wheat-maize by combining satellite images with crop model.

The simultaneous prediction of yield and maturity date has an important impact on ensuring food security. However, few studies have focused on simultaneous prediction of yield and maturity date for wheat-maize in the North China Plain (NCP). In this study, we developed the prediction model of maturity date and yield (PMMY) for wheat-maize using multi-source satellite images, an Agricultural Production Systems sIMulator (APSIM) model and a random forest (RF) algorithm. The results showed that the PMMY model using peak leaf area index (LAI) and accumulated evapotranspiration (ET) has the optimal performance in the prediction of maturity date and yield. The accuracy of the PMMY model using peak LAI and accumulated ET was higher than that of the PMMY model using only peak LAI or accumulated ET. In a single year, the PMMY model had good performance in the prediction of maturity date and yield. The latitude variation in spatial distribution of maturity date for WM was obvious. The spatial heterogeneity for yield of wheat-maize was not prominent. Compared with 2001-2005, the maturity date of the two crops in 2016-2020 advanced 1-2 days, while yield increased 659-706 kg ha-1. The increase in minimum temperature was the main meteorological factor for advance in the maturity date for wheat-maize. Precipitation was mainly positively correlated with maize yield, while the increase in minimum temperature and solar radiation was crucial to the increase in yield. The simultaneous prediction of yield and maturity can be used to guide agricultural production and ensure food security. © 2024 Society of Chemical Industry.

Quantifying City- and Street-Scale Urban Tree Phenology from Landsat-8, Sentinel-2, and PlanetScope Images: A Case Study in Downtown Beijing

Understanding the phenology of urban trees can help mitigate the heat island effect by strategically planting and managing trees to provide shade, reduce energy consumption, and improve urban microclimates. In this study, we carried out the first evaluation of high spatial resolution satellite images from Landsat-8, Sentinel-2, and PlanetScope images to quantify urban street tree phenology in downtown Beijing. The major research goals are to evaluate the consistency in pixel-level spring–summer growth period phenology and to investigate the capacity of high-resolution satellite observations to distinguish phenological transition dates of urban street trees. At the city scale, Landsat-8, Sentinel-2, and PlanetScope show similar temporal NDVI trends in general. The pixel-level analysis reveals that green-up date consistency is higher in areas with medium (NDVI &gt; 0.5) to high (NDVI &gt; 0.7) vegetation cover when the impacts of urban surfaces on vegetation reflectance are excluded. Similarly, maturity date consistency significantly increases in densely vegetated pixels with NDVI greater than 0.7. At the street scale, this study emphasizes the efficacy of NDVI time series derived from PlanetScope in quantifying the phenology of common street tree genera, including Poplars (Populus), Ginkgos (Ginkgo), Chinese Scholars (Styphnolobium), and Willows (Salix), in downtown Beijing to improve urban vegetation planning. Based on PlanetScope observations, we found that the four street tree genera have unique phenological patterns. Interestingly, we found that the trees along many major streets, where Chinese Scholars are the major tree genus, have later green-up dates than other areas in downtown Beijing. In conclusion, the three satellite observation datasets prove to be effective in monitoring street tree phenology during the spring–summer growth period in Beijing. PlanetScope is effective in monitoring tree phenology at the street scale; however, Landsat-8 may be affected by the mixture of land covers due to its relatively coarse spatial resolution.

Credit (mis)allocation under capital requirements: evidence from discontinuity in loan maturities

PurposeWe study how capital requirements, intended as a measure to ensure security for the financial system, can create moral hazard for banks in dealing with distressed debts.Design/methodology/approachOver the period spanning from 1993 to 2019, we manually gathered data on 1953 firms, identifying a total of 2,146 distress events, with 804 instances resulting in bankruptcy fillings.FindingsOur analyses at the loan level and the bank level consistently show that loans of distressed firms are much more likely to be extended when the lenders are closer to the capital requirement limit. Exploiting the discontinuity in the predetermined maturity date of loans, we provide causal evidence on the relationship between capital ratios and extension likelihood. Distressed loans that are due just before the report date (end of a quarter) are much more likely to be extended than loans due just after the report date, after controlling for loan and firm characteristics. Additional analyses show that the effects are stronger when external financing is more costly and when the banks are poorly capitalized.Originality/valueOur paper presents the first causal evidence of capital requirements on lending distortion, contributing to our understanding of the dynamics within the banking sector and providing policy implications for promoting financial stability and regulatory efficacy.

Growth and yield-related traits of near-isogenic wheat lines carrying different alleles at the Vrn-D1 locus

ABSTRACT At the major vernalization locus ‘Vrn-D1’, the spring allele, Vrn-D1a, and two winter alleles, Vrn-D1b and vrn-D1, have been identified in wheat. We conducted field trials to determine the effects of alleles on growth and yield-related traits, using near-isogenic lines developed in the genetic background of spring type wheat cultivars, ‘Abukumawase’ and ‘Asakazekomugi’, both of which carry the Vrn-D1a allele. Although maturity date of three alleles was same, the panicle development occurred earlier in the following order of genotype: Vrn-D1a > Vrn-D1b > vrn-D1. There was a significant difference in panicle development even between two winter type alleles vrn-D1 and Vrn-D1b. Grain yield and the spikelet number per spike of the original spring type cultivars were lower than those of the winter type NILs. In addition, while the young panicle development of the tillers in the spring type cultivars was found to be two weeks to one month later in the tillers than that in the main stem, young panicle development of the main stem and tillers in the winter type NILs were almost identical. Hence, winter type wheat bearing vrn-D1 which exhibit later panicle development than that bearing Vrn-D1b, was elucidated to might be more useful especially in areas with high risk of frost damage. Spring type wheat had a lower sink capacity and grain yield, meanwhile that was considered to prevent severe frost damage by allowing late-developed tillers to survive.