scholarly journals Assessing the response of maize phenology under elevated temperature scenarios

2012 ◽  
Vol 27 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Nereu Augusto Streck ◽  
Stefanía Dalmolin da Silva ◽  
Josana Andreia Langner
Keyword(s):  
Elevated Temperature ◽  
Air Temperature ◽  
Developmental Cycle ◽  
Emergence Time ◽  
Genotype X Environment ◽  
Sowing Dates ◽  
Maximum Temperatures ◽  
Synthetic Time Series ◽  
Santa Maria ◽  
Subtropical Environment

The objective of this study was to simulate the development of maize in elevated temperature scenarios at Santa Maria, RS, Brazil. The developmental cycle of maize was simulated with the Wang and Engel (WE) model with genotype-dependent coefficients for the cultivar BRS Missões. The developmental cycle was divided into vegetative phase (from emergence to silking), and reproductive phase (from silking to physiological maturity). Twelve sowing dates throughout the year were considered, resulting in emergences on the day 15 of each month all year round. Climate scenarios used were synthetic time series of 100 years of current climate and with increase in mean air temperature of +1, +2, +3, +4, and +5, with symmetric and asymmetric increases in daily minimum and maximum temperatures. As temperature increased, the number of years in which crop was killed by frost decreased, indicating that if global warming will confirm, the growing season for maize grown in subtropical environment will be longer by the end of this century. Maize vegetative and reproductive development was delayed or hastened depending upon the emergence time of the year, and if the increase in air temperature is symmetric or asymmetric, indicating complex Genotype x Environment interactions and high vulnerability of maize development to climate change.

scholarly journals Numerical Climatic Analysis of Soybean Development in Sowing Dates in Humid Subtropical Climate

2021 ◽  
Author(s):  
Mateus Possebon Bortoluzzi ◽  
Arno Bernardo Heldwein ◽  
Roberto Trentin ◽  
Ivan Carlos Maldaner ◽  
Jocélia Rosa da Silva ◽  
...  
Keyword(s):  
Meteorological Data ◽  
Sowing Date ◽  
Cycle Duration ◽  
Subtropical Climate ◽  
Climate Conditions ◽  
Development Cycle ◽  
Sowing Dates ◽  
Climatological Station ◽  
The Mean ◽  
Santa Maria

Abstract The objective of this study was to determine the mean duration and the interannual variability of phenological subperiods and total soybean development cycle for 11 sowing dates in the humid subtropical climate conditions of the state of Rio Grande do Sul. Daily meteorological data were used from 1971 to 2017 obtained from the Pelotas agroclimatological station and from 1968 to 2017 from the main climatological station of Santa Maria. The soybean development simulation was performed considering three sets of cultivars of relative maturity groups between 5.9-6.8, 6.9-7.3 and 7.4-8.0, with intervals between the sowing dates of approximately 10 days, comprising September, 21 to December, 31. The data of phenological subperiods duration and total development cycle were subjected to the exploratory analysis BoxPlot, analysis of variance and mean comparison by the Scott-Knott test, with 5% of probability. The development cycle duration is greater in Pelotas than in Santa Maria. There was a decrease in soybean cycle duration from the first to the last sowing date for both locations. The R1-R5 subperiod duration is decreasing from October to December due to photoperiod reduction.

scholarly journals Estudo de Frequência da Ocorrência de Rajada de Vento e seu Papel na Segurança das Operações Aéreas no Aeródromo Internacional de Belém-PA (Wind Occurrence Frequency Study and Its Importance in Air Operations Security on Belém's International Aerodrome)

2015 ◽  
Vol 7 (6) ◽  
pp. 1110
Author(s):  
Ingrid Monteiro Peixoto de Souza ◽  
Thiago Melo Souza ◽  
José Danilo Costa Souza Filho ◽  
Maria do Carmo Felipe de Oliveira ◽  
Dimitrie Nechet
Keyword(s):  
Air Temperature ◽  
Atmospheric Pressure ◽  
Occurrence Frequency ◽  
Equatorial Atlantic ◽  
Flight Operations ◽  
Equatorial Atlantic Ocean ◽  
Meteorological Observations ◽  
Maximum Temperatures ◽  
Meteorological Elements ◽  
Wind Intensity

Este trabalho teve como objetivo estudar a freqüência de ocorrência de rajada de vento e sua importância na segurança das operações aéreas, uma vez que estas apresentam significativas variações de intensidade do vento, podendo ocasionar, inúmeros riscos para a aviação, desde desconforto durante o voo, até perdas de vidas humanas. Os dados foram obtidos no Aeródromo Internacional de Belém do Pará, no período de 2009 a 2012, onde foram realizadas análises estatísticas, bem como, estudos das correlações dos percentuais de ocorrências com os elementos meteorológicas de superfície (temperatura do ar e pressão atmosférica), extraídas de observações meteorológicas horárias da localidade em estudo. Os resultados mostram, que nos últimos anos, a ocorrência de rajada de vento no aeródromo de Belém-Pa, vem aumentando, onde o maior registro dessa ocorrência dentro do período foi no ano de 2012. A maior frequência de eventos de rajada por intervalos de velocidade foi de 21 a 30 KT. A maior distribuição sazonal do registro de rajadas de vento ocorreu no período mais chuvoso da região, dezembro a maio, influenciadas pela nebulosidade, formada no Oceano Atlântico Equatorial, devido a atuação da ZCIT. As maiores quantidades de registros de rajadas de ventos correspondem ao período de máximas temperaturas, sugerindo uma correlação entre o aquecimento e a ocorrência de rajadas próximas a superfície terrestre. A distribuição de rajada de vento, de acordo com a orientação do vento indica predominância dos ventos de leste, de 60º a 120º.  ABSTRACT This paper aimed to study the wind occurrence frequency and its importance on the safety of flight operations, since these are significant variations in wind intensity, causing many risks to aviation, from discomfort during flight to even loss of lifes. The data were obtained from the International Aerodrome of Belém do Pará, in the period from 2009 to 2012, where statistical analyzes were performed, as well as studies of correlations of the percentage of occurrences with surface meteorological elements (air temperature and atmospheric pressure), extracted from hourly meteorological observations from the study site. The results show that in recent years, the occurrence of gust of wind at the airfield of Belém-Pa, is increasing, where the highest record of this occurrence within the period was in 2012. The higher frequency of events per burst speed intervals was 21-30 KT. The largest seasonal distribution record wind gusts occurred in the rainy season in the region, from December to May, influenced by clouds formed in the Equatorial Atlantic Ocean, due to tripping of the ITCZ​. The largest amounts of records gusty winds correspond to the period of maximum temperatures, suggesting a correlation between warming and the occurrence of near Earth's surface bursts. The distribution of wind, according to the orientation of the wind indicates predominance of winds east 60 º to 120 º.   Keywords: Wind direction, air temperature, atmospheric pressure.  

scholarly journals Winter Protection of Tree Ferns at the Royal Botanic Garden Edinburgh

2007 ◽  
pp. 141-154
Author(s):  
Andrew Ensoll ◽  
Louise Galloway ◽  
Alastair Wardlaw
Keyword(s):  
Air Temperature ◽  
Royal Botanic Garden ◽  
Botanic Garden ◽  
Tree Fern ◽  
Additional Specimen ◽  
Air Temperatures ◽  
Tree Ferns ◽  
Insulation Effect ◽  
Maximum Temperatures ◽  
Heated Glass

Ten plants of six species of tree fern were trialled for frost hardiness during the winter of 2005/06 when they were planted outdoors in the ground of an interior courtyard at the Royal Botanic Garden Edinburgh. The species were Culcita macrocarpa, Cyathea dealbata, Cyathea dregei,Cyathea smithii, Dicksonia antarctica and Thyrsopteris elegans. An additional specimen of C. dregei was planted in the main garden. The apex region of each tree fern was fitted with an electric thermometer probe to record weekly minimum and maximum temperatures. These were compared with the air temperatures of the courtyard. For thermal insulation, the trunks and crowns of the three Cyathea species were encased in straw. The prostrate rhizomes of C. macrocarpa and T. elegans were covered respectively with leaf litter, straw and a polystyrene tile. As comparators, three trunked specimens of D. antarctica were given no winter wrapping, since previous experience had shown it to be unnecessary. All ten plants survived the winter of 2005/06 which was colder than average, and put out new growth the following spring. Fronds of D. antarctica and C. macrocarpa stayed green; the fronds of the other species were withered by the coldest exposures when the air temperature reached 4.7°C.Compared with the main botanic garden, the courtyard provided a relatively mild microclimate. It was on average 2.5 °C warmer than the air temperature measured in the screen of the main garden weather station, and 7.7°C warmer than the ‘grass’ temperature in the main garden, which went down to –13°C at its lowest. All tree fern apices registered sub-zero temperatures, the range in different plants being from –0.3 to –3.4°C. The apex regions did not get as cold as the surrounding air temperature, which ranged between 0.5 and 2.3°C. The three D. antarctica (without added insulation) had minimum apical temperatures in the same range as the species that were wrapped for the winter. The insulation effect in the apex regions was also shown by the weekly maximum temperatures, which on average were lower than those of the courtyard air maxima.In conclusion, the combination of the locally favourable microclimate of the courtyard, plus appropriate trunk and crown insulation provided for some species, allowed the planting outdoors, of tree ferns normally grown in Edinburgh under heated glass.

scholarly journals Estimating the development of landrace and improved maize cultivars as a function of air temperature

2016 ◽  
Vol 46 (10) ◽  
pp. 1737-1742
Author(s):  
Josana Andreia Langner ◽  
Nereu Augusto Streck ◽  
Genei Antonio Dalmago ◽  
Lia Rejane Silveira Reiniger ◽  
Angelica Durigon ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Block Design ◽  
Sowing Date ◽  
Maize Cultivars ◽  
Randomized Block Design ◽  
Sowing Dates ◽  
Developmental Rates ◽  
Cardinal Temperatures ◽  
Santa Maria ◽  
Emergence Phase

ABSTRACT: The objective of this study was to determine the maximum development rates for the phases of emergence, vegetative and reproductive, and to test the performance of the Wang and Engel (WE) model for simulating the development of landrace and improved maize cultivars sown on different dates. Model calibration was with data collected from a field experiment with a sowing date on December 13, 2014, and the model was tested with independent data from experiments with five sowing dates (August 20 and November 4, 2013, February 3 and August 15, 2014, and January 7, 2015) in Santa Maria, RS. The experiment was a complete randomized block design with four replicates. The dates of emergence (EM), silking (R1), and physiological maturity (R6) of two landraces ('Cinquentinha' and 'Bico de ouro') and two improved maize cultivars ('BRS Planalto' and 'AS 1573PRO') were recorded. Maximum daily developmental rates varied among cultivars from 0.2400 to 0.3411 d-1 for the emergence phase, from 0.0213 to 0.0234 d-1 for the vegetative phase, and from 0.0254 to 0.0298 d-1 for the reproductive phase. The WE model adequately estimated the developmental stages of landraces and improved maize cultivars with a mean error of 3.7 days. The cardinal temperatures used in the WE model were appropriate to estimate the developmental stages of landraces and improved maize cultivars.

Agronomic studies on Vigna spp. in south-eastern Queensland. I. Phenological response of cultivars to sowing date

1979 ◽  
Vol 30 (5) ◽  
pp. 855 ◽  
Author(s):  
RJ Lawn
Keyword(s):  
Sowing Date ◽  
Reproductive Period ◽  
Day Length ◽  
Rate Of Development ◽  
South Eastern ◽  
Vigna Species ◽  
Reproductive Phase ◽  
Temperature Regimes ◽  
Sowing Dates ◽  
Maximum Temperatures

Phenological development of 16 cultivars from four Vigna species (V. radiata, green gram; V. mungo, black gram; V. angularis, adzuki bean; V. umbellata, rice bean) was studied over a range of 17 weekly sowing dates at Lawes in south-eastern Queensland. Cultivar and sowing date effects on phenology were large. In all cultivars, the rate of development during pre-flowering was associated negatively with mean day length and positively with mean maximum and/or mean minimum temperature. Cultivars differed in sensitivity to both photoperiod and temperature. Genetic lateness of flowering among cultivars was associated positively with increasing sensitivity to day length and negatively with the latitude of cultivar source. In the grams, early-flowering cultivars showed response to maximum temperatures, while the later-flowering lines responded to minimum temperatures. Rate of development in all four species during the reproductive phase was largely independent of cultivar and sowing date, per se, but rather appeared to depend on the day length and temperature regimes prevailing subsequent to the onset of flowering. The reproductive period in all species was shortest for those cultivar x sowing date combinations which commenced flowering in early autumn. Where flowering occurred in midsummer, i.e. for early sowings and for early cultivars, the reproductive period was extended as a consequence of prolonged flowering in response to the longer prevailing day lengths. As the date of flowering was delayed into mid or late autumn, the reproductive phase was extended owing to slower pod maturation rates in response to cooler prevailing temperatures. The implications of these responses on adaptation and agronomic utilization of these species are discussed.

scholarly journals Effect of temperature and carpel size during pre-anthesis on potential grain weight in wheat

1999 ◽  
Vol 132 (4) ◽  
pp. 453-459 ◽  
Author(s):  
D. F. CALDERINI ◽  
L. G. ABELEDO ◽  
R. SAVIN ◽  
G. A. SLAFER
Keyword(s):  
Heat Treatment ◽  
Environmental Conditions ◽  
Buenos Aires ◽  
Grain Weight ◽  
Effect Of Temperature ◽  
Sowing Dates ◽  
Short Period ◽  
Background Temperature ◽  
Higher Temperature ◽  
Maximum Temperatures

The effect of environmental conditions immediately before anthesis on potential grain weight was investigated in wheat at the experimental field of the Faculty of Agronomy (University of Buenos Aires, Argentina) during 1995 and 1996. Plants of two cultivars of wheat were grown in two environments (two contrasting sowing dates) to provide different background temperature conditions. In these environments, transparent boxes were installed covering the spikes in order to increase spike temperature for a short period (c. 6 days) immediately before anthesis, i.e. between ear emergence and anthesis. In both environments, transparent boxes increased mean temperatures by at least 3·8 °C. These increases were almost entirely due to the changes in maximum temperatures because minimum temperatures were little affected. Final grain weight was significantly reduced by higher temperature during the ear emergence–anthesis period. It is possible that this reduction could be mediated by the effect of the heat treatment on carpel weight at anthesis because a curvilinear association between final grain weight and carpel weight at anthesis was found. This curvilinear association may also indicate a threshold carpel weight for maximizing grain weight.

scholarly journals Sowing Dates and Soybean Cultivars Influence Seed Yield, Oil and Protein Contents in Subtropical Environment

2017 ◽  
Vol 9 (6) ◽  
pp. 188 ◽  
Author(s):  
Clovis Pierozan Junior ◽  
Jackson Kawakami ◽  
Kélin Schwarz ◽  
Renan Caldas Umburanas ◽  
Murilo Viotto Del Conte ◽  
...  
Keyword(s):  
Grain Yield ◽  
Protein Content ◽  
Management Practice ◽  
Plant Morphology ◽  
High Mass ◽  
Environment Interaction ◽  
Soybean Cultivars ◽  
Sowing Dates ◽  
Late Sowing ◽  
Subtropical Environment

The sowing date is the crop management practice with higher interference on soybean grain yield, although this interference is dependent on the genotype by environment interaction. This study was carried out to evaluate how soybean genotypes behave at different sowing times in a subtropical environment. We evaluated the grain yield, yield components, plant morphology and grain oil and protein content of four soybean cultivars (FPS Urano RR, BMX Apolo RR, BMX Energia RR and BRS 284) at three sowing dates (early, mid, and late sowing in 2010/2011 season) in Mid-South of Parana State, Brazil. Early cultivars at late sowing may have problems with mechanical harvest. The number of pods and grains differed among cultivars, and the cultivar “BRS 284” showed the best results. As an exception, the cultivar “BRS 284” showed yield stability among sowing dates. Higher amount of grain protein content occurs in middle and late sowing dates. The grain yield decreased with delay of sowing due to the reduction of the grains mass and in Southern Brazil is very important to assure high mass of seed to obtain high grain yields.

scholarly journals Non-climatic thermal adaptation: implications for species' responses to climate warming

2010 ◽  
Vol 6 (5) ◽  
pp. 669-673 ◽  
Author(s):  
David J. Marshall ◽  
Christopher D. McQuaid ◽  
Gray A. Williams
Keyword(s):  
Air Temperature ◽  
Climate Warming ◽  
Sea Water ◽  
Thermal Adaptation ◽  
Marine Species ◽  
Solar Heating ◽  
Heat Sources ◽  
Lethal Temperature ◽  
Maximum Temperatures ◽  
Rock Substratum

There is considerable interest in understanding how ectothermic animals may physiologically and behaviourally buffer the effects of climate warming. Much less consideration is being given to how organisms might adapt to non-climatic heat sources in ways that could confound predictions for responses of species and communities to climate warming. Although adaptation to non-climatic heat sources (solar and geothermal) seems likely in some marine species, climate warming predictions for marine ectotherms are largely based on adaptation to climatically relevant heat sources (air or surface sea water temperature). Here, we show that non-climatic solar heating underlies thermal resistance adaptation in a rocky–eulittoral-fringe snail. Comparisons of the maximum temperatures of the air, the snail's body and the rock substratum with solar irradiance and physiological performance show that the highest body temperature is primarily controlled by solar heating and re-radiation, and that the snail's upper lethal temperature exceeds the highest climatically relevant regional air temperature by approximately 22°C. Non-climatic thermal adaptation probably features widely among marine and terrestrial ectotherms and because it could enable species to tolerate climatic rises in air temperature, it deserves more consideration in general and for inclusion into climate warming models.

scholarly journals Maize leaf development under climate change scenarios

2010 ◽  
Vol 45 (11) ◽  
pp. 1227-1236
Author(s):  
Nereu Augusto Streck ◽  
Josana Andréia Langner ◽  
Isabel Lago
Keyword(s):  
Climate Change ◽  
Elevated Temperature ◽  
Air Temperature ◽  
Leaf Development ◽  
Flag Leaf ◽  
Climate Change Scenarios ◽  
Crop Failure ◽  
Maize Leaf ◽  
Late Emergence ◽  
Leaf Appearance

The objective of this work was to simulate maize leaf development in climate change scenarios at Santa Maria, RS, Brazil, considering symmetric and asymmetric increases in air temperature. The model of Wang & Engel for leaf appearance rate (LAR), with genotype-specific coefficients for the maize variety BRS Missões, was used to simulate tip and expanded leaf accumulated number from emergence to flag leaf appearance and expansion, for nine emergence dates from August 15 to April 15. LAR model was run for each emergence date in 100-year climate scenarios: current climate, and +1, +2, +3, +4 and +5°C increase in mean air temperature, with symmetric and asymmetric increase in daily minimum and maximum air temperature. Maize crop failure due to frost decreased in elevated temperature scenarios, in the very early and very late emergence dates, indicating a lengthening in the maize growing season in warmer climates. The leaf development period in maize was shorter in elevated temperature scenarios, with greater shortening in asymmetric temperature increases, indicating that warmer nights accelerate vegetative development in maize.

scholarly journals Analyses of the Zagreb Grič observatory air temperatures indices for the period 1881 to 2017

2018 ◽  
pp. 67-85 ◽  
Author(s):  
Ognjen Bonacci ◽  
Tanja Roje Bonacci
Keyword(s):  
Time Series ◽  
Air Temperature ◽  
Partial Sums ◽  
Daily Maximum ◽  
Absolute Maximum ◽  
Absolute Minimum ◽  
Air Temperatures ◽  
Temperature Regimes ◽  
Urban Heat ◽  
Maximum Temperatures

The paper studies time series of characteristic (minimum, mean, and maximum) daily, monthly, and yearly air temperatures measured at the Zagreb Grič Observatory in the period from 1 Jan. 1881 to 31 Dec. 2017. The following five air temperatures indices (ATI) are analysed: (1) absolute minimum yearly, monthly, and daily; (2) mean yearly, monthly, and daily minimum; (3) average mean yearly, monthly, and daily; (4) mean yearly, monthly, and daily maximum; (5) absolute maximum yearly, monthly, and daily. Methods of Rescaled Adjusted Partial Sums (RAPS), regression and correlation analyses, F-tests, and t-tests are used in order to describe changes in air temperature regimes over 137 years. Using the RAPS method the five analysed yearly ATI time series durations of 137 years were divided into two sub-periods. The analyses made in this paper showed that warming of minimum air temperatures started in 1970, mean air temperatures in 1988, and maximum air temperatures in 1998. Results of t-tests show an extreme statistically significant jump in the average air-temperature values in the second (recent time) sub-periods. Results of the t-tests of monthly temperatures show statistically significant differences between practically all five pairs (except in two cases) of analysed monthly ATI subseries for the period from January to August. From September to December the differences for most of pairs (except in six cases) of the analysed monthly ATI subseries are not statistically significant. It can be concluded that the urban heat island influenced the increase in recent temperatures more strongly than global warming. It seems that urbanisation firstly and chiefly influenced the minimum temperatures, as well as that Zagreb’s urbanisation had a bigger impact on minimum temperatures than on maximums. Increasing trend in time series of maximum temperatures started 20 years later.

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