Photothermal Environment Research Articles

Mesorhizobia strain and chickpea variety drive phenotypic plasticity of plant growth and nodulation

Chickpea (Cicer arietinum) establishes symbiotic relationships with several Mesorhizobium species and the three-way interaction between chickpea variety, Mesorhizobium strain, and environment, drives plant growth and nitrogen fixation. Here we quantified the phenotypic plasticity for shoot dry weight, nodule dry weight, nodules per plant, nodule colour, symbiotic effectiveness, and nitrogen cost in a factorial experiment combining five chickpea varieties, seven Mesorhizobium strains and three photothermal regimes. Plant growth and nitrogen fixation traits varied with variety, Mesorhizobium strain, photothermal environment and their interaction. Phenotypic plasticity was larger for nodules per plant (7.3-fold) than for shoot dry weight (2.7-fold), verifying a hierarchy of plasticities between these traits. Strain-driven plasticity of plant growth and nitrogen fixation traits was larger than variety-driven plasticity for our combination of varieties, strains, and photothermal environments, with strain-driven phenotypic plasticity being 2.7-fold vs 1.4-fold for shoot dry matter, 2.5-fold vs 1.7-fold for nodule dry weight, 7.3-fold vs 2.1-fold for nodules per plant, 3.7-fold vs 1.7-fold for nodule color, 2.9-fold vs 1.6-fold for symbiotic effectiveness, and 2.3-fold vs 1.6-fold for nitrogen cost. Our study provides insights on the phenotypic plasticity of the legume-rhizobia interaction by considering the plants as part of the rhizobia environment and vice-versa.

Photo-responsive platelet vesicles-iron oxide nanoparticles-bioglass composite for orthopedic bioengineering

In our study, we present an innovative approach to precisely modulate cellular activity and facilitate bone regeneration through non-invasive, remote stimuli application. Our methodology involves the creation of a composite material, namely platelet vesicles, iron oxide nanoparticles, and 45 s5 Bioglass (PLTV-IO NPs/BG), designed to establish a photoelectric and photothermal (PET/PTT) environment around an implant. Under near-infrared (NIR) light, the PLTV-IO NPs/BG composite demonstrates mild-hyperthermic and photoelectric responsive effects. Notably, this application enhances the mechanical strength of the hydrogel F127 and encourages sequential cell management. These observed effects collectively indicate the material’s potential in tissue engineering, specifically for bone regeneration. Our research introduces a biological therapeutic strategy that achieves remote and non-invasive regulation of cellular progression behaviors within phototherapeutic microenvironments, effectively harnessing the power of NIR light. This multidimensional approach holds promise for advancing the field of biomedical research and therapeutic applications.

Performance of Striped Bass reared at mid‐Atlantic and Gulf coast photothermal regimes

AbstractObjectiveInvestigate Striped Bass Morone saxatilis growth in different photothermal environments and generate an interest in strain‐specific broodstock development for marine net‐pen culture.MethodsIn this effort, Striped Bass strains from Atlantic (Delaware, Virginia, and Maryland) and Gulf Coast (Florida and Texas) states were cultured in recirculating aquaculture systems, simulating a full‐production cycle to early market size in each respective region's photothermal environment. The Atlantic and Gulf strains were initially maintained in recirculating aquaculture systems “nurseries” until 400 and 160 days postspawn, respectively, when offshore conditions (temperature) were conducive for stocking juvenile fish. Individuals from all strains were implanted with PIT tags and stocked (“common garden design”) into a pair of identical recirculating systems (three 5000‐L tanks/system). One system received 48 Atlantic fish/tank (16 fish/strain; Delaware, Virginia, and Maryland), and the second system received 48 Gulf fish/tank (24 fish/strain; Florida and Texas). Salinity was maintained at 30‰, and photothermal regimes corresponded with ambient ocean conditions at selected locations off the mid‐Atlantic and Gulf coasts. Studies were conducted for up to 2 years, and production parameters (feed conversion, absolute growth rate, survival) were compared.ResultThe final weights of ungraded fish in both simulated locations averaged approximately 900 g by 600 days postspawn and early market size (~1.3 kg) by 800 days postspawn.ConclusionGrowth rates differed by strain in both nursery and grow‐out phases, but the results indicate high potential for production of Striped Bass in U.S. coastal waters.

The Influence of Photovoltaic Light and Heat Environment of Ceramic Studio on Making Technology and Human Health

To study the influence of the Photovoltaic light and heat environment of the ceramic studio on human health and ceramic production technology, we take the ceramic studio of a university in Wuhan as the research object. And we use data processing and fitting algorithm to build the model. This paper provides a basis for improving the photothermal environment of ceramic studios in Wuhan. The results show that the indoor illumination of a one-sided window studio in the daytime is significantly lower than that of a two-sided window studio. The studio with one side window had about 80 Lx (unit of illuminance) less daytime interior illumination than the studio with two sides. In terms of illumination, the illumination of the studio with single-side Windows is about 100 Lx in the daytime, and that of the studio with double-side Windows is about 180 Lx.

Open-Field Agrivoltaic System Impacts on Photothermal Environment and Light Environment Simulation Analysis in Eastern China

In order to clarify the temporal and spatial changes in the internal photothermal environment in an open-field agrivoltaic system (OAVS), this paper took the OAVS in eastern China as the research object and divided the internal area into the southern area, middle area and northern area, according to the spatial structure. Further, a photothermal environment test was conducted in the above three areas in the summer and winter. The results showed that the summer average daylight rate (Rm-avg) in the middle area was 66.6%, while the Rm-avg in the other two areas was about 20%, with no significant difference. In the winter, the light environment in the southern area was slightly better, and the Rm-avg in the above three areas was 26.4%, 24.7% and 19.7%, respectively. On the whole, the relationship between the thermal environmental factors and the solar radiation intensity was consistent. Further, a 3D model of an OAVS was established using Autodesk Ecotect Analysis 2011, and the internal light environment was simulated. Compared with the measured values, the relative error was less than 10%, which verified the reliability of the OAVS model. Then, the model was used to reveal the temporal and spatial changes in the light environment of the OAVS. The simulation results showed that the daylighting rate in the summer from the ground to the height of the fig canopy inside the system was 20.7% to 61.5%. In the winter, the daylighting rate from the ground to the height of the fig canopy inside the system was 17.7% to 36.4%. The effectiveness of the OAVS in reducing the level of solar radiation intensity depended on the time of day and the angle of the sun. At the spatial scale, due to the strong consumption of light by photovoltaic panels, there was a strong horizontal and vertical light environment gradient inside the system. In conclusion, the photothermal environment research of an OAVS based on Autodesk Ecotect Analysis 2011 can not only provide a basis for agricultural production and structural design such as span, height and the laying density of PV panels, but also expand its application to regions with different latitudes and longitudes and specific climates.

Indoor photothermal environment in traditional Miao dwellings in western Hunan province: Field measurements, data simulation, and mitigation strategies

Rapid urbanization and population growth have escalated demands on the built environment, quality of life, and energy consumption. Consequently, the academic community has delved into the exploration of design methods, construction techniques, building materials, and other climate adaptation strategies, particularly focusing on traditional houses. This study examines the indoor photothermal environment and energy consumption of traditional Miao dwellings in Xiangxi Tujia and Miao Autonomous Prefecture, Hunan Province, China. Through monitoring and simulation, the paper investigates the compatibility between the dwellings and their surrounding environment, shedding light on the efficacy of traditional Miao houses in adapting to local climatic conditions. The findings reveal notable improvements in indoor temperature and humidity levels within typical Miao dwellings, showcasing enhanced climate adaptability compared to the outdoor environment. Nonetheless, the study highlights inadequacies in the indoor natural light environment of these dwellings, necessitating the introduction of light wells to meet contemporary standards. By summarizing the strengths and weaknesses of the indoor photothermal environment in traditional Miao houses in western Hunan Province, this research further evaluates the adaptability of local houses to the regional geographic climate. Additionally, the study offers targeted recommendations to address the identified weaknesses.

Promotion of dual-reaction pathway in CO2 reduction over Pt0/SrTiO3–δ: Experimental and theoretical verification

The H2 evolution is generally considered a competing reaction in photocatalytic CO2 reduction reaction (CO2RR) using H2O as the proton source. However, the reducing gas H2 generated from H2O splitting can be the proton source in CO2RR under the enhanced dynamic role of the thermal effect. The reverse water gas shift (RWGS) reaction, a CO2 hydrogenation reaction, should occur in photothermal environment owing to thermodynamically and kinetically favorable. Herein, nanostructured metal-semiconductor contact consisting of Pt nanoparticles (NPs) supported on SrTiO3–δ nanosheets with rich oxygen vacancies (Pt-OVs-STO) was constructed for investigating its feasibility and efficiency in the RWGS reaction under photothermal effect. Our experimental results substantiate that the H2 generated by H2O splitting effectively contributes to the RWGS reaction over Pt-OVs-STO system. The Pt0 NPs not only efficiently facilitate surface charge transfer, but also lower the energy barrier of the O–H bond breaking, H2 releasing, and RWGS reaction, thereby showing an outstanding CO2RR performance. The strong interaction between the Pt0 NPs and SrTiO3–δ has been extensively demonstrated by a series of experimental characterizations and density functional theory calculations. This work elucidates the relation between H2 evolution and RWGS reaction over Pt0/SrTiO3–δ structure in photothermal catalytic CO2RR using H2O as the proton source and provides new perspectives for subsequent CO2RR.

Moisture and nutrient management strategies influence the photo-thermal environment in cotton-wheat cropping system

Moisture and nutrient management strategies influence the photo-thermal environment in cotton-wheat cropping system

Photothermal Environment Strongly Affects Maize Kernel Weight

Photothermal Environment Strongly Affects Maize Kernel Weight

Kernel weight responses to the photothermal environment in maize dent × flint and flint × flint hybrids

AbstractMaize (Zea mays L.) grain yield is assumed to be source limited during the flowering period but sink limited during grain growth; however, environmental restrictions during active grain filling may strongly affect final kernel weight (KW). In this study, we evaluated the effect of natural changes in photothermal conditions during lag phase (LP) and effective grain‐filling period (EGFP) on KW, its physiological determinants, and the post‐flowering source–sink relationships of flint and semident germplasm. F1 hybrids of flint × flint and dent × flint background were tested during four seasons (Y1, Y2, Y3, and Y4). Across years, the highest KW (286 mg) was obtained under the maximum photothermal quotients during LP (PTQLP = 1.18 MJ m−2 °C−1) and EGFP (PTQEGFP = 1.07 MJ m−2 °C−1) of Y2, whereas the smallest KW (252 mg) and source–sink ratio during grain filling was obtained under the lowest PTQEGFP (.79 MJ m−2 °C−1) of Y3. Supra‐optimum temperatures during LP of Y3 negatively affected potential KW determination, and hence kernel growth rate (P < .001) as a result of reduced assimilate availability per kernel. Hybrids dent × flint exhibited higher grain yield, kernel number, and plant growth around flowering than flint × flint throughout evaluated seasons but had reduced source–sink relationship during grain filling (P < .05) and increased KW sensitivity (P < .001) to changes in the photothermal conditions. Results emphasized the importance of the photothermal environment during grain filling on KW determination (particularly for seasons with great photothermal imbalance between filling subphases) as well as the dependency of KW responses on the genetic background.

Does the photo-thermal environment limit post-flowering maize growth?

After canopy closure and in the absence of limitations by water or nutrient availability, crop growth rate (CGR) of maize (Zea mays L.) is ultimately constrained by the daily incident radiation and temperature of the environment. Sustaining maximal canopy photosynthetic capacity after-flowering is, then, a necessary but not a sufficient condition to increase maize dry-matter production. The aim of the present study was to determine the extent of the photo-thermal environment limitation to CGR during the post-flowering period in current maize crops. Dynamic of CGR was studied in two well-irrigated and nourished maize field experiments (Exp. 1 and Exp. 2 for 2010−11 and 2011−12 cropping seasons, respectively) on conventional crops (i.e. full-season hybrid planted early in the season) at Balcarce, Argentina (37° 45’ S, 58° 18’ W; 130 m a.s.l.). Two independent methods were performed to benchmark the CGR of these conventional crops during the post-flowering period: i) empirical CGR values obtained under the same weather conditions from younger maize crops, and ii) theoretically estimated potential CGR, obtained as a function of daily incident radiation and potential radiation use-efficiency (RUE). Conventional crops reached the maximal CGR near flowering in mid-January, being 51.2 g m−2 d−1 and 58.8 g m−2 d−1 in Exp. 1 and Exp. 2, respectively. Afterwards, CGR decreased progressively towards crops maturity late in March. Estimates, from either the empirical or the theoretical method, indicated that although attainable-CGR decreases progressively towards the end of the cropping season, it sustains higher values than those achieved by conventional crops after flowering. Differences in attainable vs. actual-CGR was almost exclusively attributable to RUE, which, in turn, could not be explained solely by the post-flowering foliar nitrogen withdrawal. Differences between actual (1987 g m−2 in Exp. 1 and 1614 g m−2 in Exp. 2) and potential post-flowering dry-matter production defined gaps that were in the range 18.2%–47.8%. From these results, it can be concluded that the photo-thermal environment is not, at least so far, the limiting factor to the post-flowering maize growth. Further research is needed, however, to analyze the viability of increasing potential yield of maize through the closure of these estimated gaps.

Nitrogen utilization efficiency in maize as affected by hybrid and N rate in late-sown crops

After the introduction of Bt-maize, late sowing is becoming an important strategy to stabilize yields in many areas of the Argentine Pampas. Increased nitrogen (N) availability and sharp reduction in radiation and temperature during grain filling period are dominant features of late-sown maize. Deployment of late sowing therefore requires a better understanding of the nitrogen economy of the crop in a deteriorating photothermal environment. Our aims were to: (i) evaluate the effect of late sowing on the components of maize nitrogen utilization efficiency, i.e. grain yield per unit of N uptake, (ii) assess the interactions among sowing date, hybrid and N rate on N economy, (iii) study the links between biomass and N accumulation and partitioning involved in nitrogen utilization efficiency in late sown maize. Two irrigated experiments were conducted in Paraná, Argentina (−31°50; −60°31; 110m.a.s.l) during two consecutive seasons. Treatments included the factorial combination of two hybrids with low (DK752MG) and high (DK682MG) harvest index (HI), two rates of N fertilization (0 and 200kgNha−1) and two contrasting sowing dates (September and December). Grain yield, shoot biomass, N concentration in grain, stover and biomass were measured. From these measurements we calculated N uptake, N accumulated in stover and grain and, N utilization efficiency for yield (NutEY) and biomass (NutEB) production as the ratio between yield or biomass and N uptake. A nitrogen nutrition index (NNI) was calculated to compare treatments at a similar N status. Late sowing increased soil N availability, hence reducing the response to N fertilization in comparison to traditional sowing, i.e. there were significant interactions between sowing date and N rate for most traits. The NNI accounting for the allometry of nitrogen and biomass proved to be an effective procedure in interpreting these interactions. The increase in N status reduced the NutEB, although at an equivalent NNI it was higher in traditional than in late sowing, which reflects the lower crop ability to use nitrogen in producing biomass when constrained by late growth. The hybrid DK682MG, showed more ability than DK752MG to allocate both biomass and N to grain in late sowing, as reflected by the higher HI and NHI as well as the lower amount of N accumulated in stover. Overall, our results support adaptive practices for late-sown maize in the Northern Pampas, including the use of hybrids with high partitioning of N and biomass to grain as well as the use of more conservative N fertilizer rates.

Phenology, latent heat flux and evaporative fraction in sunflower under different photo-thermal environments

Sunflower was grown in four different sowing dates with 3 irrigation regimes to create different photo-thermal environments. Duration of important phenological stages and productivity were found to be higher in winter sown crop which might be attributed to optimum photo-thermal environment. Crop duration and productivity were reduced when temperature increased during summer and rainy seasons. The day length was found to be influential at vegetative stage but no role was found in reproductive phase of the crop. The latent heat flux varied with the crop growth stage and moisture availability ranged between 8.55 to 19.11 MJ m-2 day-1 in different years and cropping season. During pick growth stage (47-97 DAS), ET consumed most of the energy, as a result evaporation fraction (EF) was higher during those days which ranged between 80-93% under different sowing dates in the first year and between 70-95% in different growth stages of second year.

Static component of photothermal response in non-transparent samples

The paper presents the analysis of the static component of temperature distribution in non-transparent samples during photothermal measurements. Analytical expressions for static part of temperature distribution in the irradiated sample and in its surroundings are determined using one dimensional model of heat transfer in a typical photothermal environment. It is established that the dominant factors that influence the shape and the mean value of the temperature distribution are optical absorption coefficient and thermal conductances of the sample and the surroundings. Important special cases are described and analytical expressions for temperatures of the front and the back side of the sample are derived.

Cropping calendar options for rice–wheat production systems at high-altitudes

The onset of rains during dry to wet transition fallow periods in rice–wheat production systems in Nepal cause substantial losses of soil nitrogen if the system is improperly managed. To make use of available nutrients and water, this transition period can either be shortened by early rice planting, or be extended by late planting, allowing a third crop to be grown. Shifting planting dates would require rice genotypes adapted to the different environments. Crop duration is influenced by both vegetative and reproductive development, which in turn is influenced by the photo-thermal environment and genotypic responses to it. An experiment was conducted to derive genotypic photo-thermal constants from phenological observations on diverse rice cultivars, which were then applied to the concept of the phenological model RIDEV to design cropping calendar options. Environmental effects on variation of crop duration were determined by planting at different dates. The risk of yield losses to sterility caused by low temperatures was estimated by simulation. Thirty-one different genotypes of rice were planted at 8 dates in 15-day intervals starting 27 April 2004 at the experimental field of the Regional Agriculture Research Station, Lumle, Nepal. The shortest duration to flowering was observed for planting dates in late May and early June. Simulation of flowering dates with RIDEV yielded correct results only for the early planting dates. For later planting dates simulated flowering dates showed an increasing deviation from the observed. In most cultivars, minimum air temperature below 18 °C during booting to heading stages caused near-total spikelet sterility and a specific delay in flowering. However, the chilling tolerant cultivars Chomrong and Machhapuchre-3 cultivated at high altitude showed less than 30% spikelet sterility even at 15 °C. Simulating crop durations with the derived thermal constants allowed evaluating the different calendar options for high altitude systems.

Application of physiological understanding in soybean improvement. I. Understanding phenological constraints to adaptation and yield potential

The purpose of this paper and its companion1 is to describe how, in eastern Australia, soybean improvement, in terms of both breeding and agronomy, has been informed and influenced over the past four decades by physiological understanding of the environmental control of phenology. This first paper describes how initial attempts to grow soybean in eastern Australia, using varieties and production practices from the southern USA, met with limited success due to large variety × environment interaction effects on seed yield. In particular, there were large variety × location, variety × sowing date, and variety × sowing date × density effects. These various interaction effects were ultimately explained in terms of the effects of photo-thermal environment on the phenology of different varieties, and the consequences for radiation interception, dry matter production, harvest index, and seed yield. This knowledge enabled the formulation of agronomic practices to optimise sowing date and planting arrangement to suit particular varieties, and underpinned the establishment of commercial production in south-eastern Queensland in the early 1970s. It also influenced the establishment and operation over the next three decades of several separate breeding programs, each targeting phenological adaptation to specific latitudinal regions of eastern Australia. This paper also describes how physiological developments internationally, particularly the discovery of the long juvenile trait and to a lesser extent the semi-dwarf ideotype, subsequently enabled an approach to be conceived for broadening the phenological adaptation of soybeans across latitudes and sowing dates. The application of this approach, and its outcomes in terms of varietal improvement, agronomic management, and the structure of the breeding program, are described in the companion paper.

Persistence of a plasma melatonin rhythm in constant darkness and its inhibition by constant light in the sleepy lizard, Tiliqua rugosa

This study determined whether a blood plasma melatonin rhythm persists in constant photothermal environments in the sleepy lizard, Tiliqua rugosa. It builds upon an earlier investigation which provided equivocal results as to whether an in vivo melatonin rhythm persists in constant dark (DD) and light (LL) and temperature in this species. Using more frequent sampling points and new assay techniques, the present study showed that the melatonin rhythm persisted for at least 6 days at temperatures of 25 and 33 degrees C in constant dark (DD). The melatonin rhythm, however, was largely eliminated in constant light (LL) at 33 degrees C, thereby contradicting some previous findings in other species of reptiles where melatonin levels were apparently insensitive to an unexpected pulse of light at night. These results demonstrate that the sleepy lizard has a persistent, possibly circadian rhythm of melatonin in DD and constant temperature, and that the rhythm is inhibited by LL and constant temperature. Therefore, the sleepy lizard pineal gland may be an independent oscillator capable of driving the melatonin rhythm and be a transducer of the seasonally changing external photothermal environment.

Light and thermal environments as modified by a wheat crop: effects on weed seed germination

Summary Knowledge of the regulatory effects of the crop canopy on weed seed germination is necessary to understand fully the behaviour of weed seed banks during a crop cycle. It is well known that canopy presence interferes with seed germination through modifications to the light and thermal environment, but the changing effect of a growing canopy has not been assessed, thus precluding the identification of shading‐intensity thresholds for triggering the different types of canopy‐detection mechanisms in different seed populations. Field experiments were performed with artificially modified thermal and light environments, using two types of seed banks (seeds buried or located at the soil surface). Conditions below a wheat canopy were modified to match light and thermal conditions prevailing on bare soil (i.e. soil without vegetation). Most weed emergence patterns during the early stages of crop establishment were not modified by the thermal regime produced by the incipient canopy compared with a bare soil control. However, the reduction of the red : far‐red ratio from the bare soil value of 1·2–0·9 below the wheat canopy reduced germination of some weed species located at the soil surface, and the effect could by reversed by far‐red filters. The weed Galinsoga parviflora developed two generations during the crop cycle. The modified light and thermal environments beneath an establishing wheat canopy was not sufficient to inhibit the germination of Galinsoga parviflora, even if seeds were located at the soil surface. Only for seeds of the second generation, dispersed from seeds of the first plant generation, was there sufficient modification of the photothermal environment below the wheat canopy to interfere with dormancy termination. Synthesis and applications. Understanding seed responses to modifications in the photothermal environment below a crop canopy (e.g. wheat crop) should allow us to improve weed management strategies by manipulating crop canopy attributes. This could be achieved by modification of sowing date, crop density, spatial arrangement and genotype. For example, increasing the crop plant density would diminish the number of weeds emerging during the first phase of crop establishment. This strategy would be appropriate where weed seeds are predominantly located at the soil surface, typically found in a no‐till cropping system.

Adaptive responses of wild mungbean (Vigna radiata ssp. sublobata) to photo-thermal environment. II. Growth, biomass, and seed yield

The leaf growth, dry matter production, and seed yield of 11 wild mungbean (Vigna radiata ssp. sublobata) accessions of diverse geographic origin were observed under natural and artificial photoperiod–temperature conditions, to determine the extent to which genotypic differences could be attributed to adaptive responses to photo-thermal environment. Environments included serial sowings in the field in SE Queensland, complemented by artificial photoperiod extension and controlled-environment growth rooms. Photo-thermal environment influenced leaf growth, total dry matter production (TDM), and seed yield directly, through effects of (mainly cool) temperature on growth, and indirectly, through effects on phenology. In terms of direct effects, leaf production, leaf expansion, and leaf area were all sensitive to temperature, with implied base temperatures higher than usually observed in cultivated mungbean (V. radiata ssp. radiata). Genotypic sensitivity to temperature varied systematically with accession provenance and appeared to be of adaptive significance. In terms of the indirect effects of photo-thermal environment, genotypic and environmental effects on TDM were positively related to changes in total growth duration, and harvest index was negatively related to the period from sowing to flowering, similar to cultivated mungbean. However, seed yield was positively related to the duration of reproductive growth, reflecting the indeterminate growth habit of the wild accessions. As a consequence, the wild accessions are more responsive to favourable environments than typically observed in cultivated mungbean, which is determinate in habit. It is suggested that the introduction of the indeterminate trait into mungbean from the wild subspecies would increase the responsiveness of mungbean to favourable environments, analogous to that of black gram (V. mungo). Although the wild subspecies appeared more sensitive to cool temperature than cultivated mungbean, it may provide a source of tolerance to the warmer temperatures experienced during the wet season in the tropics.

Adaptive responses of wild mungbean (Vigna radiata ssp. sublobata) to photo-thermal environment. I. Phenology

The phenology of 11 diverse accessions of wild mungbean was observed under natural and artificial photoperiod–temperature conditions, in order to examine whether genotypic differences might be attributed to adaptive responses to photo-thermal conditions. There was large variation in phenological response among accessions and across environments, much of which was due to differences in the duration of the pre-flowering phase. Accessions that flowered earlier tended to flower for longer, apart from 2 earlier flowering, inland Australian lines that were also earlier maturing. The patterns of response in time from sowing to flowering over environment were consistent with quantitative short-day photoperiodic adaptation, a conclusion supported by the effects of artificial day-length extension and by ‘goodness of fit’ of the observed responses to standard models relating rate of development to photoperiod and temperature. The fitted models indicated that rate of development towards flowering was hastened by warmer temperatures, and delayed by longer day lengths, with differential sensitivity between accessions to both factors. The models also suggested that photoperiod was more important for accessions collected closer to the equator, which were generally later flowering as a consequence. Conversely, temperature was relatively more important in lines from higher latitudes. Modelling also suggested that the period from first flowering to maturity was sensitive to photoperiod and temperature. Again, longer days appeared to prolong growth and delay maturity. However, cooler temperatures accelerated rather than slowed maturity, by suppressing further vegetative growth. The variation observed indicated that there is considerable scope for using the wild population to broaden the adaptation of cultivated mungbean. In particular, the unusual response of a late-flowering, photoperiod-insensitive accession warrants further study to establish whether the wild population contains a unique ‘long juvenile’ trait analogous to that being used for improving phenological adaptation in soybean.