9,026 research outputs found
Effect of frost on cereal grain crops
Loss of wheat production due to frost damage is not common in Victoria. However, while the total loss is rarely great, individual growers can suffer heavy losses in some years. The factors exposing crops to loss are discussed along with tips to minimise the potential for frost damage to occur
Analysis of different frost indexes and their potential to assess frost based on HAM simulations
To reach the climate goals of 2020 our buildings have to become a lot more energy-efficient. This challenge rests mainly on the shoulders of the renovation sector because new buildings are only a small part of our building stock. Old buildings mainly cannot get insulated on the outside because the facade is historically valuable or because of urban planning restrictions. In those cases interior insulation or - if possible - cavity insulation are the only options. However, these renovation strategies may induce severe risks for the existing structure. One of the main risks is frost damage: the interior insulation lowers the temperature of the exterior facade and decreases the drying potential to the inside which leads to an increased risk of frost damage. Most of the studies that assess the risk of frost damage struggle with the dependency of the highly variable material properties of the façade
Frost and flowers: Predicting the effects of climate change on spring frost damage using a large pollen count dataset
Background/Question/Methods 
Climate change is resulting in warmer average temperatures in much of North America, leading to earlier flowering dates for most tree genera. However, earlier flowering dates can increase the chance of frost damage which may in turn reduce or eliminate seed and fruit production. This has important implications for both forest regeneration and the organisms which depend on these resources.
Although specific examples, such as the “Easter frost” of 2007, show that frost damage can have extreme short term impacts on tree reproduction, we lack a general understanding of the frequency and importance of these events in non-agricultural contexts. Moreover, the magnitude by which climate change could increase these events is unknown.
In this study we address the following questions: 1) How good of a predictor are environmental variables (such as temperature) for pollen release date and duration across multiple genera of North American trees? 2) How frequently and to what extent has frost damage affected pollen production over the last decade? 3) Based on temporal and spatial variation in environmental factors and tree pollen phenology, what can we predict for future decades? 
To investigate these questions we make use of a large pollen count dataset, derived from asthma related data collection efforts. This dataset consists of 55 urban sites across North America, and contains six years of data. Pollen was collected daily and identified to the genus level. We also make use of nearby municipal weather stations for detailed daily weather data.
Results/Conclusions 
Certain genera, such as Acer, Alnus, Populus, and Quercus had relatively earlier pollen production times, putting them at higher risk of frost damage. Within each genus there was high variation in when the day of peak pollen counts occurred; for example Quercus peak days ranged from February 28th to June 7th. This variation was largely explained by environmental variables and site specific effects. 
We found many examples of days which had minimum temperatures sufficiently low to damage plant tissue but where pollen was still collected. For example, in the Quercus genus 223 out of 7417 pollen count observations fit these criteria, suggesting the importance of frost damage to this genus. Next, by comparing pollen count distributions between years, we show the extent to which frost damage has limited pollen production for multiple genera. Finally, we use hierarchical models to show how climate change may affect the impact of frost damage in the future.

Frost damage
Temperatures this morning (May 3) reached 25 degrees with many corn and soybean fields getting close to emerge. In a few fields, crops have just started to emerge and with the low temperatures many may wonder if replanting now is needed
FEM Analysis of Structural Behaviour of Reinforced Concrete Beam under the Effect of Frost Damage
Minimizing frost damage is one of the important durability issues for concrete structures in cold and wet areas. This paper performed a Finite Element Model (FEM) analysis on the structural behavior of reinforced concrete beam under the effect of frost damage. The frost damage was considered as degradations in two constituents: concrete material and bond between concrete and reinforcement. The constitutive models of deteriorated concrete material were proposed using a mesoscale simulation approach (Rigid Body Spring Model). DIANA FEA program was adopted for the structural analysis and experiments were also conducted for the verification. It was clarified that the structural performance of reinforced concrete beam under frost damage could be well evaluated by the FEM analysis. The assessment of the structural behavior of concrete members with frost damage would be achieved with this method
Factors Influencing Variation in Susceptibility of Prairie Plants to an Early Summer Frost in East-Central Minnesota
This study was conducted to determine the factors affecting susceptibility of prairie plants to an early summer frost at Cedar Creek Natural History Area, in east-central Minnesota. Data were collected in a previously established experimental field after temperatures fell to 1.3 °C on 20 June 1992, and to 0.3 °c on 21 June 1992. The degree of frost damage to prairie plants was recorded using a scale of frost damage based on visual criteria, and possible causes of variation in frost susceptibility were examined. The degree of frost damage was independent of plant type (grass or forb), life cycle (annual, perennial, or biennial), successional status (early or late), and species origin (native or introduced). No significant correlations were noted between plant height and mean frost damage but there was a significant negative correlation between plant height and maximum frost damage. In addition, there were no significant correlations between frost damage and mean plant biomass allocated to leaves, stems, and roots, mean biomass allocations aboveground and below-ground, and total biomass. However, plants that allocated a greater proportion of biomass to leaves were more severely damaged than plants which allocated less biomass to leaves. The ratio of leaves to total biomass appears to be critical in relation to frosting events because leaves have a high surface area to volume ratio, which allows more surface area to be exposed to cold air masses, thus increasing the freezing rate
Basic Examination on Assessing Mechanical Properties of Concrete That Has Suffered Combined Deterioration from Fatigue and Frost Damage
An examination including an evaluation of mechanical properties of concrete that had suffered combined deterioration from fatigue and frost damage was done using cylindrical specimens. The order of deterioration and degree of deterioration of the specimens were used as variables. The examination clarified that certain mechanical properties of concrete that had undergone combined deterioration were able to be evaluated by measuring the propagation speed of ultrasonic waves. The decrease in the elastic modulus and the ultrasonic velocity that accompanies the increase in the number of freeze–thaw cycles was smaller in the specimens that experienced fatigue first and then frost damage than in the specimens that experienced frost damage only. The values for mechanical properties (e.g., compressive strength, elastic modulus, and shrinkage strain) of the specimen that experienced frost damage first and then fatigue had already greatly decreased after the application of freeze–thaw cycles. Therefore, the decrease in the mechanical properties was small even with increases in the number of loading cycles. The decrease in the fatigue life of the specimen in the fatigue test was proportional to the deterioration from the preceding frost damage
Methods for identifying frost injury in immature maize seed
Fall frost damage is a major threat to maize (Zea mays L.) seed production in the central United States. Frost events prior to harvest can cause various physical, mechanical, biochemical, and physiological changes to immature seed corn. These changes can lead to decreased germination and vigor. Early detection of frost damage could reduce the financial loss caused by poor emergence when these seed lots are planted. The central hypotheses of this dissertation are that the severity of a frost event can be quantified shortly after seed has been harvested and dried, and that the magnitude of the damage is associated with seed development and genetic background of the seed. This information can be used to predict field emergence of frosted seed lots. Many different aspects of frost damage have been explored in this project, which provides several methods for identifying frost damage in maize seed. This project advances our understanding of seed physiology as related to frost damage and changes in physiology during seed maturation. Chapter 2 is a practical application of the tetrazolium test for identifying frost damage in seed corn and relating these results to vigor. Chapter 3 discusses the influence of female parent and moisture content at harvest in frost tolerance or injury. Chapter 3 also provides a detailed analysis of seed quality tests and their usefulness in predicting field emergence of frost damaged seed. Chapter 4 establishes the use of RNA extraction and qRT-PCR as a valid method for evaluating gene expression in dry maize seed
ALTERNATIVE ESTIMATION TECHNIQUES FOR ASSESSING PROBABILITY OF FROST DAMAGE IN SUBALPINE FIR TREES
Subalpine fir (Abies lasiocarpa var. lasiocarpa) is commonly used for nursery stock and Christmas tree applications. Spring frost damage to new buds, however, can jeopardize the longterm investment of growers and reduce the quality of the resulting fir trees. Hence, it is important to evaluate the risk of frost damage when considering prospective growing sites. A prediction model for bud development based on heat units can be used in conjunction with historical climate data to assess the likelihood of frost damage. That is, given the probability of a frost event at a given location and time, and the corresponding probability of bud break at that time, the probability of frost damage can be estimated. Factors affecting estimation, such as multiple environments inherent in the data, as well as temporal variation, must also be considered. These issues will be explored using parametric, non-parametric, and computer intensive estimation techniques. Examples will be demonstrated using data collected from replicated bud break experiments conducted in northern Idaho
Pulse and canola frost identification:the back pocket guide
This field guide will help you identify the common symptoms of frost damage in pulse and canola crops. It also contains pictures of other plant symptoms often confused with frost damage in these crops.
Frost damage reduces crop yield and grain quality. Early identification of symptoms allows timely crop salvage decisions to be made.
Inspect pulse and canola crops between bud formation and during pod growth if right air temperature (recorded 1.2 m above ground) falls below 2 degrees celsius and there was a frost.
Check low lying, light coloured soil types and known frost prone areas first. Then check other areas.https://researchlibrary.agric.wa.gov.au/bulletins/1139/thumbnail.jp
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