Short Growth Period Research Articles

Innovative bean sprouts basket (iBSB): A conceptual paper on a new dimension of low-cost bean sprout cultivation among agro-community

Sprouts are tiny seedlings that are produced during seed germination and have a short growth period. Across the globe and in Malaysia, more people are consuming bean sprouts due to their awareness of the need to consume “healthy foods”. The sprouts are composed of proteins, carbohydrates, and biochemical compounds with a significant amount of the recommended daily requirement for ascorbic acid and riboflavin, as well as a variety of minerals obtained through the consumption of sprouts. Moreover, sprout quality is influenced by the length, thickness, colour, and texture of the hypocotyl and roots, as well as by maintaining characteristics and little water loss after harvest. A modified atmosphere with high carbon dioxide and low oxygen can be used as a sprouting environment to control sprout growth. However, the current issues relating to open sprouting systems are bean sprout disease and high maintenance for open cultivation tanks. Thus, to solve the problem regarding the current domestic bean sprouting system, an innovative bean sprouts basket (iBSB) was innovated to control or reduce bean sprout disease for every production cycle.

The SUMO-conjugating enzyme OsSCE1a from wild rice regulates the functional stay-green trait in rice.

The functional stay-green trait is a major goal of rice breeding. Here, we cloned OsSCE1a encoding SUMO-conjugating enzyme from Yuanjiang common wild rice, which simultaneously regulates the functional stay-green trait and growth duration. Low expression or knocking out OsSCE1a corresponded to increased chlorophyll content, photosynthetic competence, N use efficiency and a shortened growth period without affecting yield. A natural MITE-transposon insertion/deletion in the OsSCE1a promoter is the functional variation that regulates these traits. OsSCE1a was selected during evolution and shows significant variation between indica and japonica rice. OsNAC2 interacts with the MITE to enhance OsSCE1a expression. Genetic manipulation of OsSCE1a revealed its potential for rice improvement. OsSCE1a-mediated SUMOylation of OsGS2 suppresses GS (involved in N assimilation) enzyme activity. OsSCE1a also regulates growth duration by SUMOylating the transcription factor such as OsGBP1, which regulates the expression of the key heading gene Ghd7. Our findings shed light on the role of SUMOylation in crops and provide a strategy for increasing agricultural productivity.

Genotypic difference in green stem disorder severity and vegetative storage protein accumulation affected by different degrees of sink limitation in soybeans [Glycine max (L.) merr.]

ABSTRACT Green stem disorder (GSD) delays leaf and stem senescence even after pods mature in soybean. In this study, the relationship between GSD severity and vegetative storage protein (VSP) dynamics was investigated under different timings and intensities of depodding treatments. Short growth period (Yukihomare, Yu), GSD-susceptible (Tachinagaha, Tc), and GSD-resistant (Touhoku 129, Th) cultivars were grown under repeated depodding treatments from the R3 growth stage by half [R3 (1/2)] or by one-third [R3 (1/3)], under a single-time depodding treatment at the R5 growth stage by half [R5 (single)], and under no depodding (control). Depodding from R3 decreased the pod number and induced GSD for both Yu and Th. However, the pod weight and stem weight per plant were statistically unchanged from those in control, indicating that remaining pods partially served as a surplus source reservoir in Yu and Th. Tc reduced the pod number and pod weight and unchanged the stem weight in depodding treatments from R3 but induced GSD regardless of the treatments. The growth of single-time depodding at R5 was not different from that of control except the growth parameters of Yu. The relative VSP content temporarily increased 14 days after R3 (DAR3) in all the treatments and cultivars. Although the relative VSP content decreased afterward in Yu and Th, that of Tc increased according to the depodding intensity. In the depodding experiments over three years, a negative correlation tended to be found after 28 DAR3 between VSP accumulation and GSD severity in Th but not in Tc, suggesting that the mechanism underlying N metabolism and GSD occurrence was different between cultivars.

Transcrystalline Mechanism of Banded Spherulites Development in Melt-Crystallized Semicrystalline Polymers.

The decades-long paradigm of continuous and perpetual lamellar twisting constituting banded spherulites has been found to be inconsistent with several recent studies showing discontinuity regions between consecutive bands, for which, however, no explanation has been found. The present research demonstrates, in three different semicrystalline polymers (HDPE, PEG10000 and Pluronic F-127), that sequential transcrystallinity is the predominant mechanism of banded spherulite formation, heterogeneously nucleated on intermittent self-shear-oriented amorphous layers excluded during the crystals' growth. It is hereby demonstrated that a transcrystalline layer can be nucleated on amorphous self-shear-oriented polymer chains in the melt, by a local melt flow in the bulk or in contact with any interface-even in contact with the interface with air, e.g., in contact with an entrapped air bubble or at the edges of the sample-or nucleated following the multiple directions and orientations induced by a turbulent flow. The bilateral excessive local exclusion of amorphous non-crystallizable material, following a short period of initial non-banded growth, is found to be the source of dislocations leading to spirally banded spherulites, through the transcrystalline layers' nucleation thereon. The present research reveals and demonstrates the sequential transcrystalline morphology of banded spherulites and the mechanism of its formation, which may lead to new insights in the understanding and design of polymer processing for specific applications.

Agronomic Advances and Challenges of Chia Production in Kenya: A Review

Chia (Salvia hispanica L.) is an annual tropical plant belonging to the Lamiaceae family. In Kenya, Chia has gained significant attention in recent years due to its nutritional benefits and increasing demand in the local and global market. This review aims to explore the potential of chia production in Kenya as a source of income for farmers. The review highlights the agronomic requirements of chia, including soil, water, and climate conditions, as well as practices necessary for successful cultivation. Chia production is becoming a favorite enterprise for most farmers in Kenya due to its ease of management and short growth period. However, a seamless production has been encountered by several challenges, including scarce information regarding its agronomic management practices, poor yielding varieties, emerging pests and diseases, and poor harvesting and post-harvesting techniques. The growing demand for chia globally presents an opportunity for Kenyan farmers to tap into this market and generate income through export. Chia, has the potential to become a new golden crop for Kenyan farmers, contributing to food security, poverty reduction, and sustainable development. However, to realize this potential, there is a need for investment in research, extension services, and market linkages to support chia production, improve agronomic practices, and create a sustainable market for the crop.

Performance of organic manures alone or combined with chemical fertilizers in increasing growth, yield, and nutritional quality of potatoes in the Eastern part of Türkiye

This study aimed to determine the effects of different types of fertilizers (organic and inorganic fertilizers) on plant growth, yield, and yield components of potatoes grown in the high-altitude plateau of eastern Türkiye in 2017 and 2019. In the experiment, single or combined doses of nitrogen (N; as ammonium sulfate) and phosphorus (P; as triple super phosphate) as inorganic fertilizers and leonardite (L) and vermicompost (V) fertilizers as organic fertilizers were used. In both years, different fertilizer treatments significantly affected plant growth, yield, and yield components. Tuber yield per hill (941.0 g), marketable tuber yield (32.71 t ha−1), total tuber yield (37.84 t ha−1), specific gravity (1. 077 g cm−3), chip productivity (35.9%), starch (13.03%) and protein (11.0%) ratios increased when N fertilizer was used in combination with vermicompost or leonardite. N fertilizer combined with V or L fertilizer increased tuber yield under harsh continental climates, short growth periods, and high altitudes.

Genome-wide analysis of MYB transcription factor family and AsMYB1R subfamily contribution to ROS homeostasis regulation in Avena sativa under PEG-induced drought stress

BackgroundThe myeloblastosis (MYB) transcription factor (TF) family is one of the largest and most important TF families in plants, playing an important role in a life cycle and abiotic stress.ResultsIn this study, 268 Avena sativa MYB (AsMYB) TFs from Avena sativa were identified and named according to their order of location on the chromosomes, respectively. Phylogenetic analysis of the AsMYB and Arabidopsis MYB proteins were performed to determine their homology, the AsMYB1R proteins were classified into 5 subgroups, and the AsMYB2R proteins were classified into 34 subgroups. The conserved domains and gene structure were highly conserved among the subgroups. Eight differentially expressed AsMYB genes were screened in the transcriptome of transcriptional data and validated through RT-qPCR. Three genes in AsMYB2R subgroup, which are related to the shortened growth period, stomatal closure, and nutrient and water transport by PEG-induced drought stress, were investigated in more details. The AsMYB1R subgroup genes LHY and REV 1, together with GST, regulate ROS homeostasis to ensure ROS signal transduction and scavenge excess ROS to avoid oxidative damage.ConclusionThe results of this study confirmed that the AsMYB TFs family is involved in the homeostatic regulation of ROS under drought stress. This lays the foundation for further investigating the involvement of the AsMYB TFs family in regulating A. sativa drought response mechanisms.

First Report of Leaf Rot Caused by Apiospora paraphaeosperma on Lily in Wuhan, China.

Lily (Lilium spp.) is a valuable ornamental bulb flower plant in Liliaceae, and its bulbs have high edible and medicinal value. Compared with bulb propagation of other lilies, seed propagation and short growth period are the most significant characteristics of Lilium×formolongi. In 2023, leaf rot disease (LRD) was observed on approximately 70% of the Lilium×formolongi seedlings sown in an experimental greenhouse in Wuhan, Hubei province, China. Irregular brown water-soaked spots were discovered in the early stages of infected seedlings. Then, spots spread throughout the leaves and caused the leaves to brown, soften, and wilted. A pathogen associated with symptoms was isolated by incubating sterilized leaves on potato dextrose agar plates at 25 ℃ for 2-3 days. Then, a pure single colony was isolated through a single hyphal tip isolation method. The fungal colony was white with abundant aerial mycelium and produced a yellow pigment diffusible into the agar. Microscopically, isolated mycelia were reticulate and pale yellow, while conidia were dark brown, smooth, and spherical, 7.31 to 6.98 × 4.03 to 3.87μm (average 5.44×5.41μm; n=30); oval in lateral view, and had a light stripe in the middle. To identify the species of the fungus at the molecular level, ITS and EF-1α genes were amplified and sequenced using primers ITS1/ITS4 (M Gardes et al. 1993) and 758F/986R (Carbone and Kohn 1999). The BLAST results in GenBank showed that the ITS(OR523578) and EF-1α(PP066842) sequences of LRD shared 99.82% and 99.24% identity with the distinct Apiospora paraphaeosperma strains (GenBank accession MT040110, ON806628.1, respectively). Combined with the morphology of the colony and conidium, the fungus was identified as Ap. paraphaeosperma. In the pathogenicity test, six healthy leaves were inoculated with mycelium disc and then kept in an incubator (22 ℃, 90% humidity, 16h light /8h darkness). The inoculated leaves showed necrosis and wilt symptoms similar to those observed in the greenhouse, while the control leaves were asymptomatic. A re-isolation, morphology identification and DNA sequencing of the fungus confirmed its infection with Ap. paraphaeosperma in Lilium spp. At present, rot caused by Ap. paraphaeosperma has only been reported in Thailand and South Korea, both of which are found on bamboo stems (Hyde et al. 2016; Sun Lul Kwon et al. 2022). As far as we know, this is the first report of leaf rot of lily caused by Ap. paraphaeosperma in China. This report can help identify this disease and further develop effective control measures.

A complete reference genome of broomcorn millet

Broomcorn millet (Panicum miliaceum L.), known for its traits of drought resistance, adaptability to poor soil, short growth period, and high photosynthetic efficiency as a C4 plant, represents one of the earliest domesticated crops globally. This study reports the telomere-to-telomere (T2T) gap-free reference genome for broomcorn millet (AJ8) using PacBio high-fidelity (HiFi) long reads, Oxford Nanopore long-read technologies and high-throughput chromosome conformation capture (Hi-C) sequencing data. The size of AJ8 genome was approximately 834.7 Mb, anchored onto 18 pseudo-chromosomes. Notably, 18 centromeres and 36 telomeres were obtained. The assembled genome showed high quality in terms of completeness (BUSCO score: 99.6%, QV: 61.7, LAI value: 20.4). In addition, 63,678 protein-coding genes and 433.8 Mb (~52.0%) repetitive sequences were identified. The complete reference genome for broomcorn millet provides a valuable resource for genetic studies and breeding of this important cereal crop.

Greenhouse gas emissions and their driving factors among different flowering Chinese cabbage (Brassica campestris L.) varieties.

Crop cultivars have an influence on greenhouse gas (GHG) emissions, and there is variation between varieties. However, there are few reports available on the differences in GHG emissions and their driving factors among vegetable varieties. In this study, we conducted a field experiment to examine the variances in GHG emissions and their contributing factors among eight flowering Chinese cabbage varieties (considering growth period, leaf shape, and colour). The results showed significant differences in GHG emissions within varieties; early-maturing varieties exhibited GHG by 25.6% and 15.3%, respectively, when compared to mid- and late-maturing varieties. Among the different leaf types and color classifications, light-colored and sharp-leafed varieties had the lower global warming potential (GWP) overall. Cumulative CO2 emissions were influenced by leaf SPAD values and biomass, while cumulative N2O emissions were driven mainly by stem thickness, carbon accumulation, leaf SPAD values, and biomass. In summary, the selection of light-colored varieties with pointed leaves and shorter growth periods in actual production contributed positively to the reduction of carbon emissions from flowering Chinese cabbage production. Through efficient variety screening, this study provides a win-win strategy for achieving efficient vegetable production while also addressing the global climate challenge.

Seasonal development rhythm of representatives of the genus <i>Spiraea</i> L. during introduction in the European North-East of Russia (Komi Republic)

Shrubs of the genus Spiraea L. are distinguished by a great variety of ornamental features, but are still underused in ornamental horticulture in the northern territories. The issues of passing the seasonal cycle of plants under new harsh climatic conditions remain fragmentarily studied. The research was aimed at examining the features and identifying patterns of the seasonal rhythm of introduced species of the genus Spiraea L. The research was carried out on the basis of the collection of the Botanical Garden of the Institute of Biology, located in the middle taiga subzone of Komi Republic. Plants to be observed included nine species of three taxonomic sections of the genus Spiraea L. The long-term averages of phenological phases and periods of seasonal rhythm of species, as well as variability of features based on the results of phenological observations for six years in the period 2013-2018 were determined. The vegetation period of plants under new conditions lasts up to 145 days and corresponds to the vegetation period of the introduction station. Shoot growth lasts from 65 to 80 days in different species. The sequence of flowering, differences in the dates of onset and duration of flowering in different Spiraea species of three sections were noted. The duration of the prefloral period ranges from 18 to 41 %, the flowering period – from 8 to 31 % of the total vegetation period of plants. The total duration of flowering of the studied species accounts for almost 100 days. The least variability is specific for the period of vegetation of species (variability index up to 5.9 %), the greatest variability – for the period of flowering of plants (variability – up to 26.7 %). The taxonomic factor (85-91 %) was revealed to influence the passage of the generative phases of the seasonal cycle. The correlation interaction was determined between the main phenophases and the early leaf fall phase. The seasonal type of growth and phenological development of Spiraea plants is characterized by an early beginning and end of vegetation, a relatively short period of growth of shoots, and the consistency of average phenological dates. This phenorhythm of the studied species of the genus Spiraea demonstrates their potential for ornamental gardening in the northern region.

Bamboo-Based Biochar: A Still Too Little-Studied Black Gold and Its Current Applications.

Biochar (BC), also referred to as "black gold", is a carbon heterogeneous material rich in aromatic systems and minerals, preparable by the thermal decomposition of vegetable and animal biomasses in controlled conditions and with clean technology. Due to its adsorption ability and presence of persistent free radicals (PFRs), BC has demonstrated, among other uses, great potential in the removal of environmental organic and inorganic xenobiotics. Bamboo is an evergreen perennial flowering plant characterized by a short five-year growth period, fast harvesting, and large production in many tropical and subtropical countries worldwide, thus representing an attractive, low-cost, eco-friendly, and renewable bioresource for producing BC. Due to their large surface area and increased porosity, the pyrolyzed derivatives of bamboo, including bamboo biochar (BBC) or activated BBC (ABBC), are considered great bio-adsorbent materials for removing heavy metals, as well as organic and inorganic contaminants from wastewater and soil, thus improving plant growth and production yield. Nowadays, the increasing technological applications of BBC and ABBC also include their employment as energy sources, to catalyze chemical reactions, to develop thermoelectrical devices, as 3D solar vapor-generation devices for water desalination, and as efficient photothermal-conversion devices. Anyway, although it has great potential as an alternative biomass to wood to produce BC, thus paving the way for new bio- and circular economy solutions, the study of bamboo-derived biomasses is still in its infancy. In this context, the main scope of this review was to support an increasing production of BBC and ABBC and to stimulate further studies about their possible applications, thus enlarging the current knowledge about these materials and allowing their more rational, safer, and optimized application. To this end, after having provided background concerning BC, its production methods, and its main applications, we have reviewed and discussed the main studies on BBC and ABBC and their applications reported in recent years.

Seaweed as a sustainable future food source

SummarySeaweed is a kind of high‐quality resource with wide distribution, short growth period and variety. They contain a variety of bioactive substances, including vitamins, proteins, polysaccharides, minerals, phenols and terpenes. Seaweed is also a source of a new class of high‐quality protein, and it also contains some active ingredients not found in land plants. These bioactive substances give seaweed powerful physiological functions so that it is used in medical, food, cosmetics and other industries. At present, the development of seaweed is still relatively simple, and its application potential is far more than that. With the support of rich active substances, seaweed is considered to be a healthy food for sustainable applications in the future. On this basis, future applications such as the development of plant‐based meat, plant‐based protein and space food using seaweed are proposed in this paper.

Evaluate the phosphorus application response in potatoes under high phosphorus soil test in Florida

Phosphorus (P) is an indispensable nutrient for agricultural crops, existing in both organic and inorganic forms within the soil matrix. However, its runoff and leaching could potentially pollute the natural water bodies worldwide through eutrophication. Despite the elevated soil P levels indicated by soil tests, the potato crop necessitates substantial P fertilization due to its relatively superficial root structure and short growth period, particularly when compared to longer-cycle agronomic crops such as corn or cotton. This investigation was designed to assess the response of potato tuber yield and quality to incremental P fertilizer applications during the 2021 and 2022 growing seasons. The research was performed in the 2021 growing season across two different agricultural sites at the Hastings Agricultural Extension Center (HAEC), incorporating eight varying rates of Triple Super Phosphate (TSP) (formulation 0-46-0% N–P2O5–K), specifically 0, 28, 56, 84, 112, 140, 168, and 224 ​kg P2O5 ha−1. In the subsequent 2022 season, the study expanded to include three additional sites at HAEC, testing six different TSP levels at 0, 22, 45, 67, 90, and 112 ​kg P2O5 ha−1. A randomized complete block design (RCBD) with four replications was employed throughout the 2021 and 2022 seasons. The cumulative data from 2021 to 2022 indicated that total and marketable yields across all sites increased in response to increasing P rates (p ​< ​0.05), exhibiting a linear trend in most locations. When aggregating data from all sites, a quadratic yield response pattern emerged. In 2021, P uptake was statistically significant, with mean values fluctuating between 18.69 and 45.09 ​kg ​P ha−1. The P application was correlated with enhanced total P removal from the soil, though the specific gravity of the tubers remained unaffected by any level of P application. The study results suggest applying P improves potato yield even if the soil test P falls in the high range.

Rapid Minimum Inhibitory Concentration (MIC) Analysis Using Lyophilized Reagent Beads in a Novel Multiphase, Single-Vessel Assay.

Antimicrobial resistance (AMR) is a global threat fueled by incorrect (and overuse) of antibiotic drugs, giving rise to the evolution of multi- and extreme drug-resistant bacterial strains. The longer time to antibiotic administration (TTA) associated with the gold standard bacterial culture method has been responsible for the empirical usage of antibiotics and is a key factor in the rise of AMR. While polymerase chain reaction (PCR) and other nucleic acid amplification methods are rapidly replacing traditional culture methods, their scope has been restricted mainly to detect genotypic determinants of resistance and provide little to no information on phenotypic susceptibility to antibiotics. The work presented here aims to provide phenotypic antimicrobial susceptibility testing (AST) information by pairing short growth periods (~3-4 h) with downstream PCR assays to ultimately predict minimum inhibitory concentration (MIC) values of antibiotic treatment. To further simplify the dual workflows of the AST and PCR assays, these reactions are carried out in a single-vessel format (PCR tube) using novel lyophilized reagent beads (LRBs), which store dried PCR reagents along with primers and enzymes, and antibiotic drugs separately. The two reactions are separated in space and time using a melting paraffin wax seal, thus eliminating the need to transfer reagents across different consumables and minimizing user interactions. Finally, these two-step single-vessel reactions are multiplexed by using a microfluidic manifold that allows simultaneous testing of an unknown bacterial sample against different antibiotics at varying concentrations. The LRBs used in the microfluidic system showed no interference with the bacterial growth and PCR assays and provided an innovative platform for rapid point-of-care diagnostics (POC-Dx).

Frequent, infinitesimal bottlenecks maximize the rate of microbial adaptation.

Serial passaging is a fundamental technique in experimental evolution. The choice of bottleneck severity and frequency poses a dilemma: longer growth periods allow beneficial mutants to arise and grow over more generations, but simultaneously necessitate more severe bottlenecks with a higher risk of those same mutations being lost. Short growth periods require less severe bottlenecks, but come at the cost of less time between transfers for beneficial mutations to establish. The standard laboratory protocol of 24-h growth cycles with severe bottlenecking has logistical advantages for the experimenter but limited theoretical justification. Here we demonstrate that contrary to standard practice, the rate of adaptive evolution is maximized when bottlenecks are frequent and small, indeed infinitesimally so in the limit of continuous culture. This result derives from revising key assumptions underpinning previous theoretical work, notably changing the metric of optimization from adaptation per serial transfer to per experiment runtime. We also show that adding resource constraints and clonal interference to the model leaves the qualitative results unchanged. Implementing these findings will require liquid-handling robots to perform frequent bottlenecks, or chemostats for continuous culture. Further innovation in and adoption of these technologies has the potential to accelerate the rate of discovery in experimental evolution.

Optimization of controlled-release urea application based on the winter wheat yield

Wheat is of great significance to ensuring national food security in China. The one-time fertilization for saving labor was common in winter wheat production in the North China Plain, which caused the excessive application of nitrogen (N) fertilizer generally. Controlled-release urea (CRU) has a good application effect in crops with short growth periods such as rice and maize. However, the applications of CRU on winter wheat with a longer growth period are fewer. To investigate the appropriate dosage and blending proportion of CRU and urea in wheat production, the field experiment with 52 treatments was conducted in 2019–2021. This relationship among N application rates, CRU release longevity, CRU proportions and winter wheat yield was systematically studied, and the binary quadratic effect models between yield and CRU factors were established. N application rates, CRU proportion and the interacted effect of CRU proportion and release longevity had the greatest effect on winter wheat yield by the main effects test and correlation analysis. The winter wheat yield could be accurately predicted by CRU proportions and CRU release longevity. The prediction errors of yield models were −9.8%∼4.9% based on the 2018 and 2022 two years winter wheat yield with CRUs application. Reducing N application rates by 20∼30% and mixing with appropriate CRU proportion would increase the yield and NUEs (nitrogen use efficiencies) of winter wheat. In the case of low CRU proportion, the wheat yield could be increased by applying the CRU with long-release longevity; when the CRU proportion was high, the yield increase effect of the CRU with short-release longevity was better. Comprehensive field production survey and Response surface methodology (RSM) partial derivative analysis, CRUs with controlled release longevity of 57d∼150d and CRU proportion of 24∼64% were the best choices for increasing wheat yield and reducing N application rates. It will facilitate the optimization of wheat CRU manufacture and application and promote the ‘Reduction and Efficiency of Chemical Fertilizers’ policies and environmental protection.

Determination of water availability and long growth period of maize plant in Boalemo Regency, Indonesia

The lack of water availability and the short period of maize growth has the potential to be the main obstacles to achieving optimal production. Therefore, this research aimed to determine the water availability and long growth period (LGP) of maize plants in Boalemo Regency, which was included in the agrokilmat zone E2. Rainfall and temperature data from Saritani, Tangkobu, and Bubaa climate stations in Boalemo Regency were used over ten years, from 2012 to 2022. The soil profile moisture content data used pF 2.5 and pF 4.2 while the tool used Cropwat8.0. Furthermore, the determination of available water and LGP was conducted using a water balance table with the Thornwaite method. The results showed that the highest and lowest water availabilities were 556 mm and 118 mm at the Saritani and Tangkobu climate stations, with a maximum LGP of maize at 242 days and 181 days, respectively. Based on climate stations, the availability of water and the amount of LGP follow the pattern of Saritani climate station > Bubaa climate station > Tangkobu climate station.

Changes and relationship of climate and late-rice yield in chenzhou city of south hunan province of CHINA

The changes and relationship of climate parameters and late-rice yield per unit area during the growth periods of late-rice from 2010 to 2019 were quantitatively analyzed in order to provide scientific guidance for countermeasures against climate change and sustainable production of late-rice. The climate parameters include cumulative daily sunshine hours (S), mean daily temperature (T), cumulative daily precipitation (P), mean daily relative humidity (H), daily highest and lowest temperatures (Th and Tl), days of high temperatures (DT ≥ 30℃ and DTh ≥ 35℃) and low temperature (DTl &lt; 15℃). Results showed that: (i) Late-rice yield was significantly increased quadratically from 5621.33 kg hm2 in 2010 to 6333.65 kg hm2 in 2019 with a mean of 5959.2 kg hm2. (ii ) According to the suitable climate conditions for growth of late-rice, T and P were low but H was suitable in the whole field growth period of late-rice, T was suitable in the transplanting-tillering stage, but was low in the booting-heading and milk ripening-mature stage. DT ≥ 30℃, DTh ≥ 35℃ and DTl &lt; 15℃ was meanly 7.7, 7.5 and 6.4 d, respectively, which showed possible occurrence of the damages to late-rice due to high and low temperatures. iii) Only T, Th and Tl in the booting-heading stage showed significant positive correlation with year, and the optimal regression models were in quadratic and exponential types. The climate parameters of S, T and Th in the boot-heading stage were significantly positively correlated with late-rice yield, and the optimal regression models were all in quadratic types. Daily highest temperature (Th) affected late-rice yield most (61.04%), followed by T (36.50%), and S affected least (2.46%). Considering the current conflict in the field planting periods between tobacco and late-rice, late rice varieties needs to be bred with short growth period and high tolerance to both high and low temperatures. Bangladesh J. Bot. 52(2): 639-647, 2023 (June) Special

Changes and relationship of climate and late-rice yield in chenzhou city of south hunan province of CHINA

The changes and relationship of climate parameters and late-rice yield per unit area during the growth periods of late-rice from 2010 to 2019 were quantitatively analyzed in order to provide scientific guidance for countermeasures against climate change and sustainable production of late-rice. The climate parameters include cumulative daily sunshine hours (S), mean daily temperature (T), cumulative daily precipitation (P), mean daily relative humidity (H), daily highest and lowest temperatures (Th and Tl), days of high temperatures (DT ≥ 30℃ and DTh ≥ 35℃) and low temperature (DTl &lt; 15℃). Results showed that: (i) Late-rice yield was significantly increased quadratically from 5621.33 kg hm2 in 2010 to 6333.65 kg hm2 in 2019 with a mean of 5959.2 kg hm2. (ii ) According to the suitable climate conditions for growth of late-rice, T and P were low but H was suitable in the whole field growth period of late-rice, T was suitable in the transplanting-tillering stage, but was low in the booting-heading and milk ripening-mature stage. DT ≥ 30℃, DTh ≥ 35℃ and DTl &lt; 15℃ was meanly 7.7, 7.5 and 6.4 d, respectively, which showed possible occurrence of the damages to late-rice due to high and low temperatures. iii) Only T, Th and Tl in the booting-heading stage showed significant positive correlation with year, and the optimal regression models were in quadratic and exponential types. The climate parameters of S, T and Th in the boot-heading stage were significantly positively correlated with late-rice yield, and the optimal regression models were all in quadratic types. Daily highest temperature (Th) affected late-rice yield most (61.04%), followed by T (36.50%), and S affected least (2.46%). Considering the current conflict in the field planting periods between tobacco and late-rice, late rice varieties needs to be bred with short growth period and high tolerance to both high and low temperatures. Bangladesh J. Bot. 52(2): 639-647, 2023 (June) Special