Ontogeny Research Articles

YOLOv5-T: A precise real-time detection method for maize tassels based on UAV low altitude remote sensing images

Maize tassels is an important organ of maize plant, and has a very important impact on yield prediction and variety breeding. Therefore, realizing the efficient and accurate detection of maize tassels in the natural environment is the key to obtain maize phenotypes in large quantities and accurately predict maize yield. This study constructed a dataset of tassels from different growth stages, proposed a YOLOv5-Tassel (YOLOv5-T) maize tassels detection model based on UAV remote sensing platform, combined with attention mechanism, YOLOv5_l network, spatial pyramid pooling structure and multi-scale extraction advantages of Atrous convolution. The experimental results showed that the Average Precision (AP) of the model for maize tassels detection could reach 98.70 %, and the detection speed was 42.2f/s. And the method in this paper had strong robustness to changes in light intensity and maize tassels at different growth stages. It was feasible to use YOLOv5-T to detect large areas of maize tassels in real time, which provided a useful reference for the estimation of maize yield and the selection of maize varieties.

Farmland mulching and optimized irrigation increase water productivity and seed yield by regulating functional parameters of soybean (Glycine max L.) leaves

In both arid and semi-arid regions, adopting field mulching can effectively optimize soil moisture distribution, enhance crop yields, and improve water productivity. While acknowledging its advantages, field mulching seems insufficient for maintaining high crop productivity due to the increasing frequency of extreme weather. Furthermore, drought often coincides with critical crop growth stages, necessitating the implementation of agricultural irrigation to ensure normal crop growth. Accordingly, we conducted a three-year field experiment from 2021 to 2023 including three typical field mulching methods (no mulching, NM; straw mulching, SM; plastic film mulching, FM) and three supplementary irrigation strategies (irrigated at the branching stage (V4), W1; irrigated at the pod-filling stage (R2), W2; irrigated at both the V4 and R2 stage, W3). Throughout the entire growth period, we monitored soil moisture conditions for each treatment, measured leaf physiological parameters at crucial growth stages, and assessed soybean yields and water productivity (WP). Our findings indicated that, relative to SM and NM, FM maintains optimal soil moisture balance, augments chlorophyll content, and enhances photosynthesis, resulting in an average yield increase of 17.0% and 38.3% over three growing seasons. Additionally, supplementary irrigation also significantly affects the growth and seed yield of soybean. FMW2 achieved the higher seed yield (4307.5kgha-1, 3-year averaged), had insignificant difference with the highest seed yield of 4568.6kgha-1, both significantly higher than other treatments. Similarly, the leaf area index, chlorophyll content, net photosynthetic rate (Pn) and transpiration rate (Tr) also presented insignificant difference between FMW2 and FMW3, while WUEleaf (Pn/Tr) of FMW2 obviously higher than that of FMW3. As a result, FMW2 achieved the highest WP of 12.2kgha-1 mm-1 over the three growing seasons, compared to the three-year average of the other treatments, the increase ranges from 5.6% to 46.7%. In summary, the FMW2 treatment optimized water distribution to meet the water demands of soybeans during the reproductive growth stages, achieving a beneficial balance between soybean seed production and WP by regulating leaf functional parameters. Future research will explore more specific irrigation scheduling techniques (e.g., precision irrigation, deficit irrigation, and sensor-based irrigation management systems) while integrating innovative agricultural film materials (e.g., biodegradable films) to further enhance crop resilience and productivity under evolving climatic conditions.

Vapour pressure deficit affects crop water productivity, yield, and quality in tomatoes

A high atmospheric vapour pressure deficit (VPD) hinders calcium absorption in tomatoes (Solanum lycopersicum L.), which severely reduces tomato yield, crop water productivity (WPcrop), and quality. Although reducing the VPD is effective for increasing tomato yield and water productivity, regulating the VPD is costly. Therefore, this study aimed to explore the effects of VPD regulation (high VPD=2.22 kPa, low VPD=0.95 kPa) during different growth stages on tomato WPcrop, yield, and quality to identify a VPD management method that saves costs and enhances the above parameters. The results showed that the yield was significantly positively correlated with fruit calcium absorption. Decreasing the VPD during the fruit expansion stage and increasing it during the flowering stage significantly increased calcium accumulation in the fruits, thereby improving tomato WPcrop, yield, and quality. Additionally, a high VPD during the flowering stage increased stomatal conductance and mesophyll conductance, thereby increasing intercellular and chloroplast CO2 concentrations and enhancing plant photosynthetic capacity, and reduced the stem water potential, leaf water potential, and leaf relative water content, thereby increasing the water potential difference, leaf hydraulic conductance, and calcium absorption. By integrating game theory and the technique for order of preference by similarity to ideal solution method, a comprehensive analysis of tomato appearance, nutrients, and flavour quality revealed that growing plants under a high VPD during the seedling, flowering, and fruit ripening stages and a low VPD during the fruit expansion stage not only enhanced the comprehensive tomato quality value but also maximally reduced the humidification cost. Conclusively, controlling the environmental VPD at 2.22 kPa during the seedling, flowering, and fruit ripening stages and at 0.95 kPa during the fruit expansion stage can effectively increase tomato WPcrop, yield, and quality. This study provides a theoretical basis for the environmental regulation of high-quality, efficient, and water-conserving cultivation of greenhouse tomatoes.

Improving cotton productivity and nitrogen use efficiency through late nitrogen fertilization: Evidence from a three-year field experiment in the Xinjiang

ContextPremature senescence is a major concern for crop production especially for high-density cotton in Xinjiang, China, when nitrogen (N) rates are reduced. This study aimed to examine the potential of late N fertilization in mitigating senescence, improving light and N use efficiency, and enhancing cotton productivity under reduced N rate. MethodsA three-year field experiment was conducted from 2019 to 2021, employing a total of 240kgN ha-1, which was one-third lower than the traditional rate of 360kgha-1. Five different N application ratios based on cotton stages were tested, with N064 (0:6:4 ratio at early: middle: late growth stages) representing late N fertilization, and N262 representing traditional ratio in fertilization. The effects of N application timing-based ratios on yield components, N use efficiency, canopy photosynthesis, and root traits were evaluated. ResultsThe results showed that N064 had the highest lint yield 2727–3305kgha-1 (2019–2021) among all treatments over the three years. Late N fertilization (N064) resulted in significant increases in boll density (4.6–10.7%), seed cotton yield (5.8–8.1%), and N use efficiency (10.5–14.1%) when compared to traditional N262. During late peak boll-setting to boll opening stages, N064 decreased leaf area index (3.5–6.6%), canopy light interception rate (3.8–11.4%), and boll capacity of root (18.1%) compared to N262, while increasing SPAD (2.3–4.8%), diffuse non-interceptance (3.9–16.6%), canopy apparent photosynthetic rate (13.2–49.4%), root biomass (19.5%), root/shoot ratio (15.0%). N064 also resulted in a higher root surface area density in deep soil than N262. ConclusionsLate N fertigation enhanced post-flowering canopy photosynthetic production by improving the cotton root-shoot relationship and delaying root and canopy senescence, resulting in improved yields and N use efficiency. This N management strategy implemented under reduced N cultivation shows promise for sustainable cotton production in Xinjiang and similar ecological regions.

Effect of Herbal Kunapajala and Different Organic Manures on Plant Growth, Quality and Yield of Withania Somnifera L. Dunal

Abstract: Cultivation of medicinal plants, especially high value medicinal plants is creating new dimension in the field of agriculture. The need for developing countries to acquire technologies and techniques for programmed cultivation of medicinal plants is a current issue. Ashwagandha, the 3rd important prioritized medicinal plant listed by National Medicinal Plant Board (NMPB) is also known as Indian Ginseng. Herbal medicines strongly involve mass appeal being safer and inexpensive. The traditional use of ‘Ashwagandha was to increase energy, youthful vigour, endurance, strength, health, nurture the time elements of the body, increase vital fluids, muscle fat, blood, lymph, semen and cell production. The total alkaloid content in the roots of the Indian types has been reported to vary between 0.13 and 0.31%, though much higher yields (upto to 4.3%) have been recorded elsewhere. In all, 13 components have been obtained chromatographically. Herbal kunapajala can be used as nutrient supplement at any growth stage of crop plant. The effectiveness of herbal kunapajala is due to the breakdown of complex compounds in to lower molecular weight compounds during the fermentation of ingredients and this make available nutrients to the plants. So, this study is planned to evaluate the effect of herbal kunapajala and organic manure on ashwagandha.

Unraveling the reasons for failure to control Amaranthus albus: insights into herbicide application at different growth stages, temperature effect, and herbicide resistance on a regional scale.

This study investigates factors contributing Amaranthus albus control failure in processing tomato fields in northern Israel. The study region is characterized by a significant climate gradient from east to west, providing the opportunity to investigate the effect of critical elements of the agricultural environment, e.g., temperature. Eight populations were collected from commercial fields in this region. Post-emergence herbicide efficacy of metribuzin, a photosystem II inhibitor, and rimsulfuron, an acetolactate synthase (ALS) inhibitor, was assessed through dose-response analyses at various growth stages. Temperature effects on control efficacy and resistance mechanisms were also explored. Standard metribuzin dose (X) was ineffective on A. albus plants with more than six true-leaves, whereas 2X dose proved effective. Rimsulfuron at 16X dose was ineffective on plants with more than four true-leaves. We report here the first case of target site resistance to ALS inhibitors in A. albus, due to point mutation in the ALS gene (Pro197 to Leu). Furthermore, our findings suggest potential involvement of CYT P450 enzymes in enhanced metabolizing of rimsulfuron. An overall decrease in dry weight was observed in response to both herbicides at 16/22 °C (P < 0.0001). Rimsulfuron was effective against only one population when applied at 28/34 °C. A possible fitness cost associated with target site-resistant biotypes was observed under low temperature conditions, leading to effective control. This regional-scale study highlights the challenges faced by growers, emphasizes the need for adapting management practices to the local climatic conditions and lays the groundwork for implementing location-specific weed management strategies in commercial fields. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Enhancing Wheat Growth, Physiology, Yield, and Water Use Efficiency under Deficit Irrigation by Integrating Foliar Application of Salicylic Acid and Nutrients at Critical Growth Stages

Transitioning from full to deficit irrigation (DI) has become a key strategy in arid regions to combat water scarcity and enhance irrigation water use efficiency (IWUE). However, implementing DI requires additional approaches to counter its negative effects on wheat production. One effective approach is the foliar application of salicylic acid (SA), micronutrients (Mic; zinc and manganese), and macronutrients (Mac; nitrogen, phosphorus, and potassium). However, there is a lack of knowledge on the optimal combinations and timing of foliar application for these components to maximize their benefits under arid conditions, which is the primary focus of this study. A two-year field study was conducted to assess the impact of the foliar application of SA alone and in combination with Mic (SA + Mic) or Mic and Mac (SA + Mic + Mac) at various critical growth stages on wheat growth, physiology, productivity, and IWUE under DI conditions. Our result demonstrated that the foliar application of different components, the timing of application, and their interaction had significant effects on all investigated wheat parameters with few exceptions. Applying different components through foliar application at multiple growth stages, such as tillering and heading or tillering, heading, and grain filling, led to significant enhancements in various wheat parameters. The improvements ranged from 7.7% to 23.2% for growth parameters, 8.7% to 24.0% for physiological traits, 1.4% to 21.0% for yield and yield components, and 14.8% to 19.0% for IWUE compared to applying the components only at the tillering stage. Plants treated with different components (SA, Mic, Mac) exhibited enhanced growth, production, and IWUE in wheat compared to untreated plants. The most effective treatment was SA + Mic, followed by SA alone and SA + Mic + Mac. The foliar application of SA, SA + Mic, and SA + Mic + Mac improved growth parameters by 1.2–50.8%, 2.7–54.6%, and 2.5–43.9%, respectively. Yield parameters were also enhanced by 1.3–33.0%, 2.4–37.2%, and 3.0–26.6% while IWUE increased by 28.6%, 33.0%, and 18.5% compared to untreated plants. A heatmap analysis revealed that the foliar application of SA + Mic at multiple growth stages resulted in the highest values for all parameters, followed by SA alone and SA + Mic + Mac applications at multiple growth stages. The lowest values were observed in untreated plants and with the foliar application of different components only at the tillering stage. Thus, this study suggested that the foliar application of SA + Mic at various growth stages can help sustain wheat production in arid regions with limited water resources.

Reducing asymmetric cost behaviors: Evidence from digital innovation

This study quantifies the impact of digital innovation on corporate performance, offering insights into the sustainability of digital innovation’s impact and providing guidance for firms embarking on their digital innovation journey. We examine the effect of digital innovation on cost stickiness using patent reports spanning from 2007 to 2022. The baseline analysis results reveal that digital innovation significantly mitigates cost stickiness in companies. This finding remains robust after addressing endogeneity concerns and conducting various robustness tests. We probe potential mechanisms and discover that digital innovation reduces cost stickiness by enhancing the quality of internal controls, improving resource-adjustment efficiency, and addressing managerial over-optimism. Heterogeneity analysis indicates a more pronounced impact of digital innovation on reducing asymmetric cost behaviors in larger firms, those beyond the growth stage, and in regions with active digital procurement, well-developed digital taxation governance, and sound judiciary infrastructures. Additionally, our expanded analysis confirms the financial benefits of digital innovation in reducing cost stickiness. A notable discovery is the negative correlation between digital transformation and cost stickiness within digitally innovative firms, underscoring the greater significance of digital innovation over mere digitization. Overall, this study significantly advances our understanding of how digital innovation influences cost management strategies.

MIKC type MADS-box transcription factor LcSVP2 is involved in dormancy regulation of the terminal buds in evergreen perennial litchi (Litchi chinensis Sonn.)

Abstract SHORT VEGETATIVE PHASE (SVP), a member of the MADS-box transcription factor family, has been reported to regulate bud dormancy in deciduous perennial plants. Previously, three LcSVPs were identified from litchi genome, and LcSVP2 was highly expressed in the terminal buds of litchi during growth cessation or dormancy stages and down-regulated during growth stages. In this study, the roles of LcSVP2 in governing litchi bud dormancy was examined. LcSVP2 was highly expressed in the shoots, especially in the terminal buds at growth cessation stage, whereas low expression was showed in roots, female flowers and seeds. LcSVP2 was found to be located in the nucleus and have transcription inhibitory activity. Over-expression of LcSVP2 in Arabidopsis thaliana resulted in a later flowering phenotype compared to the wild-type control. Silencing LcSVP2 in growing litchi terminal buds delayed re-entry of dormancy, resulting in significantly lower dormancy rate. The treatment also significantly up-regulated litchi FLOWERING LOCUS T2 (LcFT2). Further study indicates that LcSVP2 interacts with an AP2-type transcription factor, SMALL ORGAN SIZE1 (LcSMOS1). Silencing LcSMOS1 promoted budbreak and delayed bud dormancy. ABA (200 mg/L), which enforced bud dormancy, induced a short-term increase in the expression of LcSVP2 and LcSMOS1. Our study reveals that LcSVP2 may play a crucial role, likely together with LcSMOS1, in dormancy onset of the terminal bud and may also serve as a flowering repressor in evergreen perennial litchi.

Response of vegetation phenology to climate factors in the source region of the Yangtze and Yellow Rivers

Abstract Exploring the impact of climate factors on vegetation phenology is crucial to understand climate-vegetation interactions as well as carbon and water cycle in ecosystems in the context of climate change. In this paper, we extracted the vegetation phenology data from 2002 to 2021 based on the dynamic threshold method in the source region of the Yangtze and Yellow Rivers. Trend and correlation analyses were used to investigate the relationship between vegetation phenology and temperature, precipitation and their spatial evolution characteristics. The results showed that (1) From 2002 to 2021, the multi-year average start of growing season, end of growing season, length of growing season for plants were concentrated in May, October and 4-6 months, with a trend of 4.9 days (earlier), 1.5 days (later), 6.3 days/10a (longer) respectively. (2) For every 100 m elevation increase in the vertical direction, the start, end, length of growing season were correspondingly delayed by 1.8 days, advanced by 0.8 days, and shortened by 2.6 days. (3) The impacts of temperature and precipitation on vegetation phenology varied at different stages of vegetation growth. Influencing factors of spring phenology experienced a shift from temperature to precipitation, while autumn phenology experienced precipitation followed by temperature. (4) The climate factors in the previous period significantly affected the vegetation phenology in study area and the spatial variability was obvious. Specifically, the temperature in April significantly affected the spring phenology and precipitation in August widely affected autumn phenology.

Phenotype, Biomass, Carbon and Nitrogen Assimilation, and Antioxidant Response of Rapeseed under Salt Stress

Salt stress is one of the major adverse factors affecting plant growth and crop production. Rapeseed is an important oil crop, providing high-quality edible oil for human consumption. This experiment was conducted to investigate the effects of salt stress on the phenotypic traits and physiological processes of rapeseed. The soil salinity was manipulated by setting three different levels: 0 g NaCl kg−1 soil (referred to as S0), 1.5 g NaCl kg−1 soil (referred to as S1), and 3.0 g NaCl kg−1 soil (referred to as S2). In general, the results indicated that the plant height, leaf area, and root neck diameter decreased with an increase in soil salinity. In addition, the biomass of various organs at all growth stages decreased as soil salinity increased from S0 to S2. The increasing soil salinity improved the distribution of biomass in the root and leaf at the seedling and flowering stages, indicating that rapeseed plants subjected to salt stress during the vegetative stage are capable of adapting their growth pattern to sustain their capacity for nutrient and water uptake, as well as leaf photosynthesis. However, as the soil salinity increased, there was a decrease in the distribution of biomass in the pod and seed at the maturity stage, while an increase was observed in the root and stem, suggesting that salt stress inhibited carbohydrate transport into reproductive organs. Moreover, the C and N accumulation at the flowering and maturity stages exhibited a reduction in direct correlation with the increase in soil salinity. High soil salinity resulted in a reduction in the C/N, indicating that salt stress exerted a greater adverse effect on C assimilation compared to N assimilation, leading to an increase in seed protein content and a decrease in oil content. Furthermore, as soil salinity increased from S0 to S2, the activity of superoxide dismutase (SOD) and catalase (CAT) and the content of soluble protein and sugar increased by 58.39%, 33.38%, 15.57%, and 13.88% at the seedling stage, and 38.69%, 22.85%, 12.04%, and 8.26% at the flowering stage, respectively. In summary, this study revealed that salt stress inhibited C and N assimilation, leading to a suppressed phenotype and biomass accumulation. The imbalanced C and N assimilation under salt stress contributed to the alterations in the seed oil and protein content. Rapeseed had a certain degree of salt tolerance by improving antioxidants and osmolytes.

Coupled one-off alternate furrow irrigation with nitrogen topdressing at jointing optimizes soil nitrate-N distribution and wheat nitrogen productivity in dryland

The judicious management of water and nitrogen (N) is pivotal for augmenting crop productivity and N use efficiency, while also mitigating environmental concerns. With the advent of the High−Farmland Construction Program in China, one−off irrigation has become feasible for most dryland fields, presenting a novel opportunity to explore the synergistic strategies of water and N management. This study delves into the impact of one−off alternate furrow irrigation (AFI) and topdressing N fertilizer (TN) on soil nitrate−N distribution, and N productivity—including plant N accumulation, translocation, and allocation, and grain yield, protein content, N use efficiency of winter wheat (Triticum aestivum L.) in 2018−2019 and 2019−2020. Experimental treatments administered at the jointing stage comprised of two irrigation methods—every (EFI) and alternative (AFI) furrow irrigation at 75 mm, and two topdressing N rates—0 (NTN) and 60 (TN) kg N ha−1. Additionally, a conventional local farmer practice featuring no irrigation and no topdressing N (NINTN) was served as control. Compared to NINTN, EFINTN substantially increased aboveground N accumulation, grain yield, and protein yield, albeit with a reduction in grain protein content by 8.1%−10.6%. AFI, in turn, led to higher nitrate−N accumulation in the 60−160 cm soil depth at booting and anthesis, but diminished levels at maturity, resulting in a significant surge in N accumulation from anthesis to maturity and its contribution to grain, N fertilizer partial factor productivity (PFPN), and N uptake efficiency (NUPE), thereby promoting grain yield by 9.9% and preserving grain protein content. Likewise, TN enhanced soil nitrate−N at key growth stages, reflected in marked improvements in N accumulation both from booting to anthesis and from anthesis to maturity, as well as in grain yield, protein content, and protein yield. The combination of AFI and TN (AFITN) yielded the highest grain yield, protein content, with PFPN, NUPE, and N internal efficiency outstripping those of EFINTN, but not AFINTN. In essence, one−off AFI coupled with TN at the jointing stage is a promising strategy for optimizing soil nitrate−N and enhancing wheat N productivity in dryland where one−off irrigation is assured.

Performance of Blackgram as Influenced by Water Soluble Fertilizers and PGPR under Rainfed Situation

Lower production potential of blackgram grown under rainfed situation due to lack of proper nutrition during critical crop growth stages. So, investigation was carried out with an objective to study the effect of water-soluble fertilizers and PGPR on performance of blackgram during Kharif-2019, a field study was carried out at University of Agricultural and Horticultural Sciences, Shivamogga which comes under Southern Transition Zone of Karnataka. Experimental design was laid out in randomized complete block design with thirteen treatments and replicated thrice. Treatments include combination of 19:19:19, monopotassium phosphate @ different dosage foliar spray with and without PGPR treatment along with package of practices. Water soluble fertilizers viz., 19:19:19 (N: P: K) and mono potassium phosphate (0:52:34) were used in treatment combinations along with PGPR. The Results revealed that, foliar application of 19:19:19 and mono potassium phosphate @ 1 per cent each at 30 and 45 days after sowing + PGPR along with a package of practice recorded significantly higher plant height, number of branches per plant, leaf and stem dry weight, crude protein (26.54 %), seed yield (1167 kg ha-1) and haulm yield (2019 kg ha-1) over package of practice treatment and also positive correlation was found between growth and yield parameters with seed yield and haulm yield.

FinTech developments and their heterogeneous effect on digital finance for SMEs and entrepreneurship: evidence from 47 African countries

Purpose Lack of access to finance is a major constraint to the growth of small and medium-sized enterprises (SMEs) and entrepreneurship in developing countries. The recent proliferation of mobile phone services, access to the internet and emerging technologies has led to a surge in the use of FinTech in Africa and is transforming the financial sector. This paper aims to examine whether FinTech developments heterogeneously contribute to the growth of digital finance for SMEs and entrepreneurship in 47 African countries from 2013 to 2020. Design/methodology/approach The paper uses a novel method of moments quantile regression, which deals with heterogeneity and endogeneity in diverse conditions for asymmetric and nonlinear models. Findings The empirical results reveal that the rise of FinTech companies offering services in Africa heterogeneously increases digital finance for SMEs and entrepreneurship in their different stages of growth. FinTech developments have a strong and positive impact in countries with higher levels of digital finance than those with lower levels. FinTech developments and digital finance positively and significantly influence entrepreneurship in Africa, particularly in the nascent and transitional development stages of entrepreneurship. Institutional quality has a considerable positive moderating effect when used as a control rather than an interaction variable. Practical implications The results suggest the need to promote FinTech developments in Africa: to provide a wide range of alternative digital finance schemes to SMEs and to promote entrepreneurship, especially in countries where entrepreneurship is in the nascent and transitional development stages. The results also underscore the need to promote FinTech development through supportive regulations and institutional quality to reduce risks related to FinTech and digital financing schemes. Originality/value To the best of the authors’ knowledge, this paper is one of the first attempts to account for the often overlooked heterogeneity effects and show that the influence of FinTech developments is not homogenous across the varying development stages of digital finance and entrepreneurship.

Is hand-wrist radiography still necessary in orthodontic treatment planning?

The aim of our study is to compare the relationship between hand-wrist and cervical vertebra maturation stages with chronological age and to investigate the effect of malocclusion type on the relationship between these methods. Hand-wrist and cephalometric radiographs of 1000 patients (526 females, 474 males) with a mean age of 13.41 ± 1.83 were analyzed. The methods of Bacetti et al. were used for the cervical vertebra maturation stage, and Björk, Grave and Brown's methods were used for the hand-wrist maturation stage. One-way ANOVA test was applied to compare skeletal classes between them. Tukey post hoc test was used to determine the differences. The relationship between the malocclusion type, cervical vertebra and hand-wrist maturation stages was evaluated with the Spearman correlation test. Spearman's correlation coefficient was 0.831, 0.831 and 0.760 in Class I, II and III females, respectively. In males, it was calculated as 0.844, 0.889 and 0.906, respectively. When sex and malocclusion were not differentiated, the correlation was found to be 0.887. All were statistically significant (P < 0.001). The highest correlation was observed in class III males, while the lowest was found in class III females. Cervical vertebrae can be used safely to assess pubertal spurt without hand-wrist radiography. Diagnosing growth and development stages from cephalometric images is important in reducing additional workload and preventing radiation risk.

Deciphering of the morpho-physiological traits of two native grasses from Argentina with contrasting drought resistance strategies

Context Semiarid environments, such as the Patagonian shrublands, are characterised by having shrubby patches surrounded by grasses with different ecophysiological strategies to tolerate long dry periods. Aims We hypothesised that coexisting grasses of the Patagonian rangeland, already classified as drought-escaping or drought-tolerant, have different traits according to the season and the annual rainfall events. Methods Two dominant native grasses were selected: Pappostipa speciosa (evergreen) and Poa ligularis (deciduous). Samples were collected in the four seasons for the term of 1 year. Rainfall events and soil water content of each season were determined. Spring was the wettest season and autumn the driest. Physiological (relative water content, pigments, hormones), biochemical (polyphenols, antioxidant activity) and morphological traits were measured in the four seasons. Key results P. speciosa was characterised by keeping evergreen leaves with high production of polyphenols as secondary metabolites with high antioxidant capacity during the dry autumn and winter seasons. P. ligularis was characterised by high contents of gibberellin (GA1), auxin (IAA), total phenols, total flavonoids and tartaric acid esters, and high antioxidant capacity in roots during the autumn dry season. In addition, P. ligularis leaves had higher content of carotenoids and polyphenols than P. speciosa during the summer dry season. Conclusions The major adaptive strategy to tolerate dry periods is the high activity of the secondary metabolism, mainly in leaves in P. speciosa (a drought-tolerant grass) and in roots in P. ligularis (a drought-escaping grass). Implications Rainfall variations during a year can affect the phenological growth stages and the metabolism of two native grasses from Argentina characterised by different drought resistance mechanisms.

A prediction model of rubber content in the dried root of Taraxacum kok-saghyz Rodin based on near-infrared spectroscopy

BackgroundTaraxacum kok-saghyz Rodin (TKS) is a highly potential source of natural rubber (NR) due to its wide range of suitable planting areas, strong adaptability, and suitability for mechanized planting and harvesting. However, current methods for detecting NR content are relatively cumbersome, necessitating the development of a rapid detection model. This study used near-infrared spectroscopy technology to establish a rapid detection model for NR content in TKS root segments and powder samples. The K445 strain at different growth stages within a year and 129 TKS samples hybridized with dandelion were used to obtain their near-infrared spectral data. The rubber content in the root of the samples was detected using the alkaline boiling method. The Monte Carlo sampling method (MCS) was used to filter abnormal data from the root segments of TKS and powder samples, respectively. The SPXY algorithm was used to divide the training set and validation set in a 3:1 ratio. The original spectrum was preprocessed using moving window smoothing (MWS), standard normalized variate (SNV), multiplicative scatter correction (MSC), and first derivative (FD) algorithms. The competitive adaptive reweighted sampling (CARS) algorithm and the corresponding chemical characteristic bands of NR were used to screen the bands. Partial least squares (PLS), random forest (RF), Lightweight gradient augmentation machine (LightGBM), and convolutional neural network (CNN) algorithms were employed to establish a model using the optimal spectral processing method for three different bands: full band, CARS algorithm, and chemical characteristic bands corresponding to NR. The model with the best predictive performance for high rubber content intervals (rubber content > 15%) was identified.ResultThe results indicated that the optimal rubber content prediction models for TKS root segments and powder samples were MWS–FD CASR–RF and MWS–FD chemical characteristic band RF, respectively. Their respective RP2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{R}}_{{\ ext{P}}}^{2}$$\\end{document}, RMSEP, and RPDP values were 0.951, 0.979, 1.814, 1.133, 4.498, and 6.845. In the high rubber content range, the model based on the LightGBM algorithm had the best prediction performance, with the RMSEP of the root segments and powder samples being 0.752 and 0.918, respectively.ConclusionsThis research indicates that dried TKS root powder samples are more appropriate for constructing a rubber content prediction model than segmented samples, and the predictive capability of root powder samples is superior to that of root segmented samples. Especially in the elevated rubber content range, the model formulated using the LightGBM algorithm has superior predictive performance, which could offer a theoretical basis for the rapid detection technology of TKS content in the future.

Hyperspectral Data for Early Identification and Classification of Potassium Deficiency in Soybean Plants (Glycine max (L.) Merrill)

Identifying potassium (K+) deficiency in plants has traditionally been a difficult and expensive process. Traditional methods involve inspecting leaves for symptoms and conducting a laboratory analysis. These methods are not only time-consuming but also use toxic reagents. Additionally, the analysis is performed during the reproductive stage of growth, which does not allow enough time for corrective fertilization. Moreover, soybean growers do not have other tools to analyze the nutrition status during the earlier stages of development. Thus, this study proposes a quick approach for monitoring K+ in soybean crops using hyperspectral data through principal component analysis (PCA) and linear discriminant analysis (LDA) with a wavelength selection algorithm. The experiment was carried out at the Brazilian National Soybean Research Center in the 2017–2018, 2018–2019, and 2019–2020 soybean crop seasons, at the stages of development V4–V5, R1–R2, R3–R4, and R5.1–R5.3. Three treatments were evaluated that varied in K+ availability: severe potassium deficiency (SPD), moderate potassium deficiency (MPD), and an adequate supply of potassium (ASP). Spectral data were collected using an ASD Fieldspec 3 Jr. hyperspectral sensor. The results showed a variation in the leaf spectral signature based on the K+ availability, with SPD having higher reflectance in the visible region due to a lower concentration of pigments. PCA explained 100% of the variance across all stages and seasons, making it possible to distinguish SPD at an early development stage. LDA showed over 70% and 59% classification accuracies for discriminating a K+ deficiency in the simulation and validation stages. This study demonstrates the potential of the method as a rapid nondestructive and accurate tool for identifying K+ deficiency in soybean leaves.

Effects of Great Gerbil Disturbance on Photosynthetic Characteristics and Nutrient Status of Haloxylon ammodendron

Rodents, such as those that feed on plants and nest in plant roots, can significantly affect the growth and development of desert plants. The aim of this study was to investigate the effects of Rhombomys opimus disturbance on the photosynthetic characteristics and nutrient status of Haloxylon ammodendron at different growth stages in the Gurbantunggut Desert. The effects of great gerbil disturbance on the photosynthetic characteristics of H. ammodendron at different growth stages were investigated by measuring the gas exchange parameters, instantaneous water use efficiency, and chlorophyll fluorescence parameters of H. ammodendron at different ages (young, middle, and adult) under the disturbance of great gerbils. The soil nutrients in the assimilated branches and rhizosphere of H. ammodendron at different growth stages were tracked to reveal the relationship between the H. ammodendron nutrient content and gerbil disturbance. The results showed that great gerbil disturbance decreased the organic carbon content in the rhizosphere soil of adult H. ammodendron and increased the total nitrogen content in the rhizosphere soil and the nitrogen and potassium contents in the assimilated branches at each growth stage. The net photosynthetic rate and instantaneous water use efficiency of H. ammodendron decreased at each growth stage, and the maximum photochemical efficiency and non-photochemical quenching parameters of the young H. ammodendron decreased. However, the actual photochemical efficiency and photochemical parameters of the middle H. ammodendron increased. It was concluded that the disturbance of great gerbils decreased the photosynthetic capacity of H. ammodendron and increased the content of total nitrogen in the soil and nitrogen and potassium in the plant. This study revealed that the Gurbantunggut Desert great gerbil and H. ammodendron do not have a simple predation relationship. It laid a foundation for the study of the moderate disturbance threshold and better use of the mutually beneficial relationship between the two.

Effect of Irrigation Regimes and Applied Nitrogen Levels on Growth and Physiological Responses of Ryegrass

A field experiment was conducted at the Instructional-cum-Research (ICR) Farm, Assam Agricultural University, Jorhat. The experiment was laid out in split-plot design with three replications. The treatments consisted of five levels of irrigation in main plot viz., I0:Rainfed, I1: Irrigation at critical growth stages, I2: Irrigation at IW:CPE ratio of 1.0, I3: Irrigation at IW:CPE ratio of 1.2 and I4: Irrigation at IW:CPE ratio of 1.4 along with four levels of N- N0: 0 kg N/ha, N1: 30 kg N/ha, N2: 60 kg N/ha and N3: 90 kg N/ha in sub- plots. The soil of the experimental site was sandy loam in texture, medium in organic carbon, available N and available P2O5, acidic in reaction and low in available K2O. The result revealed that the highest leaf area index (LAI) recorded in irrigation at IW:CPE ratio of 1.4 at all the three cuts respectively during both the years. The crop growth rate (CGR), relative growth rate (RGR) and net assimilation rate (NAR) of ryegrass as influenced by different irrigation regimes were found to be non-significant at 30 DAS while at later growth stages i.e. 45 DAS, 60 DAS, 90 DAS and 120 DAS were significantly influenced during both the years. The application of irrigation at IW:CPE of 1.4 produced higher value of CGR, RGR but the highest NAR was recorded in rainfed treatment. The data on LAI as influenced by different N levels was found to be significant in all three cuts. Application of 90 kg N/ha recorded the highest LAI. The CGR, RGR and NAR as influenced by different N levels were found to non significant at 30 DAS but significantly influenced at later growth stage i.e. 45 DAS, 60 DAS, 90 DAS and 120 DAS during both the years. The highest data on CGR and RGR were recorded in 90 kg N/ha but the highest NAR was found in 0 kg N/ha.