Winter Growth Research Articles

Analysis on the Economic Feasibility of a Plant Factory Combined with Architectural Technology for Energy Performance Improvement

In this study, a comparative economic analysis was conducted for typical greenhouses, plant factories with natural and artificial light, and those with only artificial light, based on the insulation, artificial light, and photovoltaic (PV) installation costs. In addition, the results of research on primary energy consumption and greenhouse gas (GHG) emissions from the use of fossil fuels were presented. By comparing the case-wise annual energy consumption, when all energy sources were converted into primary energy consumption based on the applied coefficients for collection, transport, and processing, to unify calculations for different fossil fuel energy sources, the case of the installed PV systems exhibited large reductions, of 424% and 340%, in terms of primary energy consumption and GHG emissions, respectively. Furthermore, electric heating resulted in higher primary energy consumption and GHG emissions than oil. When the economic analysis included the plant factory installation cost used to maintain the temperature required for plant growth in winter, the PV installation exhibited the highest cost; additionally, all plant factories showed an investment payback period of seven to nine years, which is comparable to typical greenhouses. Based on these results, we aim to reduce the use of fossil fuels for sustainable energy by combining architectural technology for improved energy performance in the agricultural environment.

TX‐BHS berseem clover germplasm

AbstractTX‐BHS (Reg. no. GP‐312, PI 699627) is a germplasm line of berseem clover (Trifolium alexandrinum L.) selected for increased cold tolerance and hard seed production. This germplasm line was developed by Texas A&M AgriLife Research at Overton and is intended to extend the range and utility of this annual clover species. Berseem is well adapted to wet and waterlogged soils and has potential for expanded use in both pasture and cover crop systems. Improved hard seed production would allow expanded use of berseem in reseeding pasture and cropping systems. Three cycles of recurrent half‐sib selection and two cycles of recurrent phenotypic selection were applied to the variable base population (Mississippi Winter Hardy Berseem) at Overton, TX, from 1982 to 1988. Selection was successful in improving hard seed levels of TX‐BHS relative to ‘Bigbee’ berseem. Selection for winter survival and reduced cold damage caused a reduction in winter growth of TX‐BHS berseem relative to Bigbee berseem. This growth pattern shift was only observed in only one trial. The actual impact of selection on winter survival and cold tolerance of TX‐BHS berseem needs further study.

Soil nitrogen and water management by winter-killed catch crops

Abstract. Improving N cycling in agroecosystems is one of the key challenges in reducing the environmental footprint of agriculture. Further, uncertainty in precipitation makes crop water management relevant in regions where it has not been necessary thus far. Here, we focus on the potential of winter-killed catch crops (CCs) to reduce N leaching losses from N mineralization over the winter and from soil water management. We compared four single CCs (white mustard, phacelia, Egyptian clover and bristle oat) and two CC mixtures with 4 and 12 plant species (Mix4 and Mix12) with a fallow treatment. High-resolution soil mineral N (Nmin) monitoring in combination with the modelling of spatiotemporal dynamics served to assess N cycling under winter-killed CCs, while soil water was continuously monitored in the rooting zone. Catch crops depleted the residual Nmin pools by between 40 % and 72 % compared to the fallow. The amount of residual N uptake was lowest for clover and not significantly different among the other CCs. Catch crops that produce high N litter materials, such as clover and mustard leaves, showed an early N mineralization flush immediately after their termination and the highest leaching losses from litter mineralization over the winter. Except for clover, all CCs showed Nmin values between 18 % and 92 % higher on the sowing date of the following maize crop. However, only Mix12 was statistically significant. Catch crops depleted the soil water storage in the rooting zone during their growth in autumn and early winter, but preserved water later on when their residues covered the ground. The shallow incorporation of CC residues increased water storage capacity during the cropping season of the main crop even under reduced soil water availability. Hence, catch cropping is not just a simple plant cover for the winter but improves the growth conditions for the following crop with decreased N losses. Mixtures have been shown to compensate for the weaknesses of individual CC species in terms of nutrient capture, mineralization and transfer to the following main crop as well as for soil water management. Detailed knowledge about plant performance during growth and litter mineralization patterns is necessary to make optimal use of their potential.

Evaluating the effect of seasonal conditions on metabolism and photosynthetic performance of Picochlorum sp. and its influence on biomass productivity

Microalgae productivity is majorly influenced by changing seasonal conditions affecting its micromorphology, physiology and metabolic activity. In this study, microalga belonging to the Picochlorum sp. isolated from tropical habitat was found to be better adapted and twice as productive in the summer tropical simulations compared to winter. Reduced growth in winter was metabolically corroborated by an increase in carbon squandering pathways in winter simulating conditions through the upregulation of photorespiratory pathway and 2-fold increase in biomass accumulation in summer simulation through the upregulation of carbon conserving pathways. Ultrastructural studies revealed increased thylakoid membrane space in winter simulation compared to summer simulating conditions affecting diffusion and metabolite distribution. Furthermore, reduction in photosystem II electron transport rate with nearly half the performance index was observed in winter. This study narrows down the possible metabolic, physiological, and ultrastructural changes at seasonal abiotic variations critically affecting the microalgae carbon fixation and productivity.

An Air Convection Wall with a Hollow Structure in Chinese Solar Greenhouses: Thermal Performance and Effects on Microclimate

A Chinese solar greenhouse (CSG) is a horticultural facility that uses solar energy to promote a growth environment for crops and provides high-efficiency thermal storage performance to meet the demand of vegetables’ growth in winter. Besides being an important load-bearing structure in CSGs, the north wall is a heat sink, storing during the day in order to act as a heat source during the night. At times, the night temperature is lower than the minimum growth temperature requirement of vegetables, and the additional heating is needed. Therefore, optimizing the heat storage and release performance of the north wall in a CSG is an important approach for improving growth environment and reducing consumption of fossil fuel. This study proposes a heat storage north wall with a hollow layer on the basis of air convection, aiming to optimize the utilization of solar energy in CSGs. By the air convection effects, the hollow layer collects and stores surplus solar energy in the air during the day and transfers it to the cultivation space for heating at night. Additionally, field tests were conducted to compare the natural and forced convection strategies via airflow and heat transfer efficiency. The final effect on the indoor temperature ensured that the lowest temperatures at night were above 5 °C under both the natural and forced convection strategies during the winter in the Beijing suburbs where the average minimum temperature is below −10.8 °C during the experimental period. The hollow structure improves the utilization efficiency of solar energy in CSGs and ensures winter production efficiency in northern China.

A short survey of key silage-making practices on Northern Ireland dairy farms, and farmer perceptions of factors influencing silage quality

AbstractNorthern Ireland dairy farmers (n = 174) were surveyed to identify key silage-making practices, and factors perceived to influence the quality of grass silage made on their farms. The majority of farmers (65%) harvested grass for silage three times/year: 62% normally used a contractor, while 47% routinely used a silage additive. Delays to mowing and delays to harvesting due to adverse weather or poor ground conditions were perceived to have a large or very large impact on silage quality (68% and 53% of farmers, respectively). Inadequate wilting, poor-quality swards on owned land, on rented land and “contamination” of first-cut grass with autumn or winter growth herbage were all perceived as having a large or very large impact on silage quality (32%, 27%, 40%, 30% of farmers, respectively). Over the previous decade, 11%, 41% and 37% of farmers claimed a small, moderate or large improvement in silage quality, mainly due to earlier cutting of grass and ensiling better quality swards.

Quantitative Analysis of Winter Wheat Growth and Yields Responding to Climate Change in Xinjiang, China

The knowledge of climate change effects on variations of winter wheat yields are crucial for productions. Our objectives were to investigate the relationship between yield-related indices of winter wheat and the related climatic variables (selected using variance inflation factors) at the 20 sites of Xinjiang, China over 1981–2017. The background of climate and yield changes was analyzed from temporal and spatial respects. The number of independent climatic variables was selected with the variance inflation factor method to remove the multicollinear feature. The Pearson correlation was conducted between the first difference values of climatic variables and yield-related indices of winter wheat (namely plant height, growth period duration, 1000-kernel weight, kernel number per ear, biomass and yield) to find the key climatic variables that impacted winter wheat growth and yields. The multi-variate linear and nonlinear functions were established step by step using the selected key climatic variables. The best function was determined for each site (significant for p < 0.05). From the results, there were general wetter and warmer trends of the climatic variables. Correspondingly, shortened winter wheat phenology and increased growth and yields were observed for most sites. Still, the climatic trends had mixed effects on winter wheat yields. The effects of precipitation, mean air temperature and relative humidity on plant height and growth period duration agreed well. Different sites had different major climatic drivers for winter wheat growth or yields, and the best functions of growth and yields could be linearly or nonlinearly, mostly described by multi-variate functions. The winter wheat growth or yield indices were also found to be closely connected with the soil water content status at the eight sites. The relationship between winter wheat growth or yield and climate provided useful references for forecasting crop production and for projecting the impact of future climate changes.

Elevated root-zone temperature promotes the growth and alleviates the photosynthetic acclimation of cucumber plants exposed to elevated [CO2

Greenhouse cultivation forms a relatively closed environment for heat preservation in winter, which inevitably leads to a lack of atmospheric CO2 concentration ([CO2]), and thus low [CO2] level has become a limiting factor for the photosynthesis and growth of greenhouse vegetables. Most cucurbits and solanaceous vegetables are sensitive to low temperature, but it is difficult to keep the optimum root-zone temperature (RZT) for them in greenhouse soil cultivation in winter. Therefore, low RZT is another limiting factor for greenhouse vegetables growth in winter. This study investigated the effects of [CO2], RZT, and their interactions on cucumber yield, growth, photosynthesis, and photosynthate allocation in four open-top chambers for a growth period of 73 days after transplanting. We found elevated RZT increased yield and total dry weight of cucumber plants to a greater extent than elevated [CO2]. We also observed long-term elevated [CO2] limited the increase of net photosynthetic rate (Pn) and decreased the stomatal conductance (Gs) and transpiration rate (Tr) of cucumber plants at ambient RZT, resulted in the photosynthetic acclimation, as illustrated by the significant reduction of nitrogen concentration and the increased concentrations of soluble sugar and starch in leaves. In comparison, the combination of elevated [CO2] and RZT decreased the concentrations of soluble sugar and starch and maintained the nitrogen concentration in leaves, which caused a higher Pn, Gs and Tr. Meanwhile, more soluble sugar and starch were allocated from leaves to roots due to the higher root respiratory under elevated [CO2] and RZT treatment. Moreover, elevated RZT could facilitate the mineral nutrients absorption by roots and the upward transportation because of the larger root system and higher Tr. Therefore, elevated RZT could offset the decrease in Pn and improve Gs and Tr under elevated [CO2], which indicated an alleviation of the photosynthetic acclimation of cucumber plants exposed to long-term elevated [CO2].

267 Effect of Hay Type on the Winter Growth of Bos Grunniens Raised in Eastern Kentucky

Abstract Bos grunniens (yak) have been utilized as a source of fiber, milk, dung, meat and transportation in the high-altitude regions of Asia for centuries. Limited research has been conducted on the species in North America. The objective of this on-farm research was to evaluate the effect of hay type on growth rate of growing yaks. Forages evaluated included alfalfa (A), orchardgrass-red clover (O) and a cool-season pasture grass species mixture (P). The experimental design was a partially balanced 3x3 Latin square with an extra pen. Yaks were stratified to pens by age and sex resulting in a pen of mixed sex (3 males/2 females) recently weaned calves, a pen of five yearling females, and two pens of five yearling males. Each period lasted for 45 days and animal weights were collected at the beginning and end to assess weight change and daily gain. Hay offered was weighed and feeding losses were visually estimated to determine hay DM disappearance. Forage samples were collected and analyzed for nutrient content. Data were analyzed using the PROC GLM procedure of SAS. No carryover effects were noted and means were separated using Tukey’s multiple comparison test where α=0.10. Forage type had a significant impact on period weight change of growing yaks during the winter with O having greater weight gain (9.5 kg) than P (-4.7 kg) with A being intermediate (8.5 kg). Forage DM disappearance when expressed as percent of body weight was greater for A (2.70) compared to P (2.25) while O (2.28) was not different from either. Forage type and quality can impact weight gain and forage disappearance during the winter months for growing yaks with higher quality forage providing greater weight gain.

Experimental testing of density- and season-dependent growth in vegetative Fucus aquaculture and modelling of growth over one year for different cultivation scenarios

In the Kiel Fjord, western Baltic Sea, an experimental culture of Fucus vesiculosus and Fucus serratus has been established in order to develop a sustainable method for biomass production of these species. The cultivation method includes the unattached rearing of fronds in drifting baskets and their vegetative reproduction by cutting of small vegetative apices. In this study, we performed culture experiments to measure growth rates with this method at different initial stocking densities (1–5 kg m−2) and during different seasons of the year. Using the results, we modelled growth over 1 year for different cultivation scenarios (different initial stocking densities (1–4.75 kg m−2) and harvest densities (1.25–5 kg m−2)) in order to identify optimal scenarios and estimate annual yields and the number of necessary harvests in these scenarios. Fucus vesiculosus showed a parabolic yield–density relationship with decreasing yields at high initial stocking densities (> 2.5 kg m−2). In contrast, F. serratus showed an asymptotic yield–density relationship with rather constant yields at high initial stocking densities. Both species showed a typical seasonal growth pattern with low growth rates during winter and high growth rates during summer; however, F. serratus seemed to be growth limited during summer which was not observed for F. vesiculosus. The modelling results reflected the results of the Density experiment: for F. vesiculosus, optimal cultivation scenarios were found for intermediate cultivation densities (initial stocking densities, 1.75–2.25 kg m−2; harvest densities, 3–4 kg m−2); for F. serratus, optimal cultivation scenarios included higher densities (initial stocking densities, 2.5–4 kg m−2; harvest density, 5 kg m−2). The model scenarios predicted maximal annual yields of 6.65–6.76 kg m−2 for F. vesiculosus and 6.88–6.99 kg m−2 for F. serratus. For both species, the number of harvests necessary to achieve these yields varied depending on the cultivation scenario from 2 to 6. Scenarios with only 1 harvest per year yielded slightly lower annual yields. We conclude that the modelling results offer a valid and helpful orientation for future efforts to produce Fucus species in commercial culture.

Crop Cycle and Tillage Role in the Outbreak of Late Wilt Disease of Maize Caused by Magnaporthiopsis maydis.

The destructive maize late wilt disease (LWD) has heavy economic implications in highly infected areas such as Israel, Egypt, and Spain. The disease outbreaks occur near the harvest, leading to total yield loss in severe cases. Crop rotation has long been known as an effective means to reduce plant diseases. Indeed, agricultural soil conservation practices that can promote beneficial soil and root fungi have become increasingly important. Such methods may have a bioprotective effect against Magnaporthiopsis maydis, the LWD causal agent. In this two-year study, we tested the role of crop rotation of maize with either wheat or clover and the influence of minimum tillage in restricting LWD. In the first experiment, wheat and clover were grown in pots with LWD infected soil in a greenhouse over a full winter growth period. These cultivations were harvested in the spring, and each pot’s group was split into two subgroups that underwent different land processing practices. The pots were sown with LWD-sensitive maize cultivar and tested over a whole growth period against control soils without crop rotation or soil with commercial mycorrhizal preparation. The maize crop rotation with wheat without tillage achieved prominent higher growth indices than the control and the clover crop cycle. Statistically significant improvement was measured in the non-tillage wheat soil pots in sprout height 22 days after sowing, in the healthy plants at the season’s end (day 77), and in shoot and cob wet weight (compared to the control). This growth promotion was accompanied by a 5.8-fold decrease in pathogen DNA in the plant stems. The tillage in the wheat-maize growth sequence resulted in similar results with improved shoot wet-weight throughout the season. In contrast, when maize was grown after clover, the tillage reduced this parameter. The addition of commercial mycorrhizal preparation to the soil resulted in higher growth measures than the control but was less efficient than the wheat crop cycle. These results were supported by a subsequent similar experiment that relied on soil taken from commercial wheat or clover fields. Here too, the wheat-maize growth cycle (without permanent effect for the tillage) achieved the best results and improved the plants’ growth parameters and immunity against LWD and lowered pathogen levels. In conclusion, the results of this study suggest that wheat and perhaps other crops yet to be inspected, together with the adjusted tillage system, may provide plants with better defense against the LWD pathogen.

Quinoa for the Brazilian Cerrado: Agronomic Characteristics of Elite Genotypes under Different Water Regimes

Quinoa stands out as an excellent crop in the Cerrado region for cultivation in the off-season or irrigated winter season. Here, we tested the effects of different water regimes on the agronomic characteristics, physiology, and grain quality of different elite quinoa genotypes under field conditions. The experiment was conducted under field conditions at Embrapa Cerrados (Planaltina, DF, Brazil). The experimental design was in randomized blocks, in a split-plot scheme, with four replications. The plots were composed of 18 quinoa genotypes and modified BRS Piabiru (the currently used genotype), and the split-plots were divided into 4 different water regimes. The following variables were evaluated: productivity and productivity per unit of applied water (PUAA), plant height, flavonoids, anthocyanins, gas exchange, chlorophyll, leaf proline, and relative water content. Our results showed that water regimes between 309 and 389 mm can be recommended for quinoa in the Cerrado region. CPAC6 and CPAC13 presented the highest yield and PUAA under high and intermediate WRs, and hence were the most suitable for winter growth under irrigation. CPAC17 is most suitable for off-season growth under rainfed conditions, as it presented the highest PUAA under the low WRs (247 and 150). CPAC9 stood out in terms of accumulation of flavonoids and anthocyanins in all WRs. Physiological analyses revealed different responses of the genotypes to water restriction, together with symptoms of stress under lower water regimes. Our study reinforces the importance of detailed analyses of the relationship between productivity, physiology, and water use when choosing genotypes for planting and harvest in different seasons.

Reducing competition in forage maize intercropped with tall fescue through herbicides, plant types, and sowing density

Forage maize is the predominant crop in the intensive dairy farming regions of Europe. This crop, however, is associated with considerable nitrate leaching and decreasing soil organic matter concentrations. Catch crops installed after maize harvest can usually only be sown late in the growing season in North-West Europe to tackle these problems efficiently. Intercropping maize with grass species such as tall fescue has the potential to result in a timely developed grass sward before the winter, capable of assimilating important quantities of carbon and soil residual nitrogen and to buildup soil organic matter. Yet, the intercropped grass might compete with the maize for water and nutrients. Here, we report, for the first time, the effect of (i) herbicide combinations, (ii) tall fescue sowing density and method, (iii) tall fescue morphotype, and (iv) the maize maturity group on the functioning of forage maize intercropped with tall fescue. We assessed maize and intercropped tall fescue yields and studied the N uptake and the effect on soil residual nitrate of the intercropped grass. We found that every kg dry matter ha−1 of tall fescue aboveground dry matter, present at the end of the autumn, came at a cost of 1.4 kg dry matter ha−1 of maize dry matter yield. Herbicide treatments can regulate grass-maize competition, whereas lower sowing densities of the intercropped grass or different sowing methods of the intercropped grass had no effects. Despite the superior winter growth of the Mediterranean tall fescue morphotype compared to the continental tall fescue, the reduction in soil residual nitrate was similar for both morphotypes. We demonstrate that tall fescue intercropped in maize can be an alternative to cover crops installed after the harvest of maize, to reduce nitrate leaching, and to compensate for the soil organic matter losses associated with forage maize production.

Spatiotemporal patterns of phenology of the alien Phaeophyceae Sargassum muticum on the Atlantic coast of Morocco

The present study focused on the dynamics of the phenology and life cycle of the Phaeophyceae invader Sargassum muticum at three sites on the Atlantic coast of Morocco over a period of two years (2013 and 2014). The results showed that S. muticum has two distinct growth phases; one with slower growth in winter followed by one with faster growth in spring-early summer, when the species exhibited high elongation and branching activities with thalli length ranging from 1 to more than 5 m depending on the study site. The site S1, with a rocky substratum covered by submerged sands, promotes thalli elongation, with maximum lengths of 643.33 11.10 cm recorded in July. At the rocky sites (S2 and S3), the maximum length of the seaweed depends on the pools’ depth. Although the elongation of thalli is enhanced by the water body depth, the settlements’ density (5-48 ind. m–2) seems to be mainly related to the nature of the substrate. The maturity index progressively increases from spring to early summer, when it reaches the highest values. S. muticum seems to be more abundant and more easily acclimated in shallow rockpools (sufficiently lighted and semi-exposed to wave action at the mid and lower tidal levels) than in protected sandy bottom sites with low hydrodynamic forces.

Registration of ‘SB255’ winter barley

Abstract‘SB255’ (Reg. no. CV‐373, PI 693987) is a six‐rowed hulled barley (Hordeum vulgare L.) cultivar with winter growth habit. The cultivar was released by the Virginia Agricultural Experiment Station in May 2019. SB255 is widely adapted, high yielding, high grain volume weight, and medium tall. It has good winterhardiness and good straw strength. The spikes of SB255 are strap and slightly waxy with no overlapping lateral kernels and with long awns. Prior to being named, SB255 was tested under the experimental designation VA11B‐141 (LA). It was derived from the cross Spont03‐44/VA01B‐44 and developed using a modified‐bulk breeding method. It was evaluated from 2013 to 2019 in the Virginia Official Variety Trials at five to six locations. SB255's average grain yield (5,214 kg ha–1) was similar to the check cultivars ‘Secretariat’ and ‘Thoroughbred’ but significantly (P ≤ .05) higher than ‘Atlantic’, ‘Price’, ‘Callao’, ‘Nomini’, and ‘Wysor’. Average grain volume weight of SB255 (60.8 kg hL–1) was similar to Secretariat and Price but exceeded (P ≤ 0.05) those of Thoroughbred, Atlantic, Callao, Nomini, and Wysor. Head emergence of SB255 was similar to Thoroughbred and 2–5 d later than winter feed barley cultivars Secretariat, Atlantic, Price, Callao, and Nomini. SB255 was developed primarily as a feed barley cultivar. It provides barley producers and end users in the eastern United States with a high‐grain‐yielding cultivar having good to moderate resistance to all diseases prevalent in the eastern United States, including Fusarium head blight (FHB), and also lower deoxynivalenol (DON) accumulation in the grain.

Juvenile Coho and Chinook Salmon Growth, Size, and Condition Linked To Watershed‐Scale Salmon Spawner Abundance

AbstractAnadromous Pacific salmon Oncorhynchus spp. are semelparous, and resource subsidies from spawning adult salmon (marine‐derived nutrients [MDN]) benefit juvenile salmonids while they rear in freshwater. However, it is unclear if juvenile salmon populations respond predictably to the abundance of spawning salmon at the watershed scale. To address whether hypothesized benefits to rearing juveniles scale up to population and watershed scales, we examined juvenile Coho Salmon Oncorhynchus kisutch and Chinook Salmon O. tshawytscha growth, fork length, condition, and abundance as a function of MDN assimilation throughout the Unalakleet and North rivers in western Alaska. Additionally, a mark–recapture experiment provided abundance estimates of Coho Salmon smolts emigrating from these two rivers. Prior to spawning, residual MDN from past years offered little advantage to juvenile salmon. However, after the arrival of spawning adults, juveniles demonstrated a positive relationship between MDN and fish size, growth, and condition in fall and winter. Out‐migrating smolts also benefitted from MDN resources via increased size and growth rates. Coho Salmon smolt abundance was unrelated to total spawner biomass, but a positive relationship between MDN assimilation and smolt abundance suggested a possible effect on overwinter survival. Furthermore, similar trends in spawner biomass and the abundance of age‐1 smolts suggested that age at smolting was influenced by MDN. These relationships support the hypothesis that salmon spawner abundance during Coho and Chinook Salmon rearing is an important factor in the juvenile productivity of these species.

Genome-wide identification and functional characterization of the PheE2F/DP gene family in Moso bamboo

BackgroundE2F/DP proteins have been shown to regulate genes implicated in cell cycle control and DNA repair. However, to date, research into the potential role of the Moso bamboo E2F/DP family has been limited.ResultsHere, we identified 23 E2F/DPs in the Moso bamboo genome, including nine E2F genes, six DP genes, eight DEL genes and one gene with a partial E2F domain. An estimation of the divergence time of the paralogous gene pairs suggested that the E2F/DP family expansion primarily occurred through a whole-genome duplication event. A regulatory element and coexpression network analysis indicated that E2F/DP regulated the expression of cell cycle-related genes. A yeast two-hybrid assay and expression analysis based on transcriptome data and in situ hybridization indicated that the PheE2F-PheDP complex played important roles in winter Moso bamboo shoot growth. The qRT-PCR results showed that the PheE2F/DPs exhibited diverse expression patterns in response to drought and salt treatment and diurnal cycles.ConclusionOur findings provide novel insights into the Moso bamboo E2F/DP family and partial experimental evidence for further functional verification of the PheE2F/DPs.

To grow or survive: Which are the strategies of a perennial grass to face severe seasonal stress?

Abstract More severe seasonal stresses resulting from climate change affect the survival of perennial plant species. The growth–survival trade‐off exemplified in dormant species is a key issue to understand adaptation. As the validity of this trade‐off has yet to be tested in non‐dormant species, it was assessed by exploring the intraspecific variability of strategies to face drought and frost within perennial ryegrass. Three common gardens compared 385 European perennial ryegrass populations along a latitudinal environmental gradient over 3‐years. Persistence, productivity and physiological traits were recorded under contrasting seasonal environments. Decoupling plant responses, that is, growth under favourable summers/winters and plant survival under harsh summers/winters, showed a general trade‐off between growth potential and dehydration survival. Three groups of perennial ryegrass populations were identified according to their contrasting strategies: (a) year‐round productive but stress sensitive populations from wet areas; (b) drought‐tolerant populations with low summer growth potential from drought‐prone areas and (c) frost‐tolerant populations with low winter growth potential from frost‐prone areas. Overall, the populations surviving drought best were more resource conservative, whereas populations of the other groups were more resource acquisitive. However, such overall functional patterns were less meaningful than seasonal variations of resource acquisition potentials. The predicted potential biogeographical distribution of these groups suggests shifts of areas of suitability under climate change over the next decades in Europe. Dehydration escape and dehydration tolerance through reduction of growth potential in summer may become the strategies best adapted to an increasingly large area of Europe. The large intraspecific variability of phenological adaptations within perennial ryegrass reveals that the seasonal modulation of growth potential is crucial to plant adaptation under severe chronic abiotic stresses. The global plant economics spectrum cannot account for contrasting seasonal trade‐offs, which points out the importance of integrating phenological traits as key components of plant strategies. The identification of the trade‐off between growth potential and frost or drought stress survival in this non‐dormant species provides key knowledge to understand the future regional distribution of this major species for grassland ecosystem services. A free Plain Language Summary can be found within the Supporting Information of this article.

Food and initial size influence overwinter survival and condition of a juvenile marine fish (age-0 Atlantic cod)

In subarctic Newfoundland, age-0 Atlantic cod (Gadus morhua) settle into coastal habitats in several summer–autumn pulses, resulting in broad length-frequency distributions before winter. Low winter temperatures and potential decreases in food availability pose challenges for young-of-year fish. To examine how size variation affects overwintering success under contrasting food scenarios, we conducted 114-day laboratory feeding trials at ambient overwinter sea temperatures, using demersal age-0 cod collected from Newman Sound, Newfoundland. We reared two size classes of juvenile cod under four daily ration levels (starvation, low, medium, high). We used Fulton’s K condition factor to interpret effects of food availability and fish size on survival over winter. We showed that small amounts of consumed food (<1% BW·day−1) maximized winter growth and condition potential of juvenile cod in Newfoundland waters. With no food, survival of small cod dropped below 80% on Day 47, whereas survival of large juveniles remained >80% until Day 74. Therefore, we expect higher survival of earlier settlers and increased size-selective mortality in age-0 cod during either unproductive or protracted winters, when food abundance is often low.

Frost Stress Tolerances and Cut Roses: A Review

In order to meet the challenges of providing food to the ever increasing population of the world, there is an insistent need to boost crop yield. Unfortunately, the production of agriculture decreasing due to various environmental factors including frost and cold are very important, especially in winter. Indeed, frost is the most important abiotic problem and one of the doctrine limiting factors affecting plant growth and development in winter. Despite various obvious symptoms under frost stress, the yellowing of leaves, weak germination, curling of leaves, decreased rate of cell swelling and wilting, reduced flower opening, curling of petals leads to the cells death. This severe damage is largely due to the sensitive drying associated with freezing during frost. In addition, signal transduction is to switch on frost response genes and transcription factors to mediating stress tolerance, thus underline mechanism of frost stress and genes involve in the frost/cold stress signal network is very important for plant growth and development. In present review, plant significances in daily life and issues related to abiotic stresses such as frost and cold tolerance mechanisms are discussed.