scholarly journals Identification of Key Periods of Temperature Influence on ‘Sirora’ Pistachio Nut Quality

2021 ◽  
pp. 1-8
Author(s):  
Jianlu Zhang ◽  
Trevor Ranford

The methodology of r contour mapping was used in this study of ‘Sirora’ pistachio (Pistacia vera) to establish whether there are any significant relationships between fruit quality characteristics in commercial pistachio production and air temperature in the year before the harvest of the crop as measured at a nearby meteorological station. The work was done near Mildura in Australia. Blank nut percentages were found to be reduced by lower minimum temperatures in mid to late August (southern hemisphere). The percentage of narrow-split nuts was decreased by higher maximum temperatures across almost the whole growing season. Damaged-shell nuts were reduced by higher average daily minimum temperatures between 26 Nov. and 3 Feb. The technique of r contour mapping is shown to have potential as a way to provide early warning of possible quality problems before harvest and as a means of generating hypotheses for future physiological studies

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 509a-509
Author(s):  
C.E. Wieland ◽  
J.E. Barrett ◽  
D.G. Clark ◽  
G. J. Wilfret

Four poinsettia cultivars were grown in glass greenhouses in Gainesville, Fla., in the Fall 1997 to evaluate differences in floral initiation and subsequent development. Three means of regulating photoperiod were 1) natural days 2) long-day lighting to 6 Oct. and then natural days (lights out) 3) long-day lighting to 6 Oct., and then short-day conditions by black cloth for 15 h (black cloth). At 2-day intervals, sample meristems were collected and examined for initiation of reproductive development. Average minimum and maximum temperatures during the first two weeks of October were 22 and 29 °C, respectively, with an average temperature of 25.3 °C. The overall average temperature was 23.2 °C from planting to anthesis. Differences in anthesis dates among cultivars were primarily due to time to initiation vs. rate of development. Under natural days, `Lilo' initiated first on 8 Oct. and `Freedom', `Peterstar', and `Success', followed by 6, 8, and 18 days, respectively. Lights out resulted in `Lilo' initiating 17 Oct., followed by `Freedom', `Peterstar', and `Success' initiating 7, 12, and 15 days later, respectively. Differences between cultivars in time of initiation was reduced under black cloth, where `Lilo' initiated 14 Oct., followed by `Freedom' 2 days later, and `Peterstar' and `Success' 7 days afterward. Initiation was positively correlated to visible bud and anthesis. First color was positively correlated to initiation and visible bud, with the exception of `Lilo'. Growth room studies conducted using various high temperatures and photoperiods indicated similar trends.


2020 ◽  
pp. 5-18
Author(s):  
Yuliya A. Brovka ◽  
Ivan V. Buyakov

It is important to study the heat and moisture supply of the territory under climate warming conditions in Belarus since 1989, as well as changes in the occurrence frequency of extreme moisture conditions. The features of the spatial change in the averaged hydrothermal coefficient (HTC) for the period of climate warming (1989–2019) and the colder period preceding it (1960–1988) in the months of the growing season were revealed based on the maps constructed by interpolation. A decrease in the aridity of conditions in May and September in the southeast and east of the country, an increase in aridity in June and August (especially in the southern regions), an increase in the area with excessive moisture in July and its decrease in September were defined. The article shows the features of changes in the frequency of droughts (HTC ≤ 0,7), less arid conditions (HTC = 0,71–1,0) and excessive moisture (HTC > 1,6) from May to September in 1989–2019, according to compared with the period 1960–1988. It was found that during the period of climate warming from May to September, there is a significant increase in the droughts frequency at meteorological stations in various regions of Belarus. A decrease in the number of years with drought in May and June is observed at several eastern and southern meteorological stations, in August – at the Zhitkovichi meteorological station, in September – at the Kostyukovichi meteorological station. The frequency of arid conditions in May, July and September decreases at many meteorological stations, and its changes are characterized by territorial heterogeneity. An increase in the number of years with less arid conditions is observed in most of Belarus in June and August. A significant increase in the frequency of excessive moisture was noted in July in most of the territory of Belarus, in May – in some regions. A decrease in the frequency of excessive moisture is observed at many meteorological stations in June and August; the number of years with excessive moisture increases only in the northern region. Spatial heterogeneity and less pronounced changes in the frequency of excessive moisture are noted in September.


2013 ◽  
Vol 10 (7) ◽  
pp. 4465-4479 ◽  
Author(s):  
K. L. Hanis ◽  
M. Tenuta ◽  
B. D. Amiro ◽  
T. N. Papakyriakou

Abstract. Ecosystem-scale methane (CH4) flux (FCH4) over a subarctic fen at Churchill, Manitoba, Canada was measured to understand the magnitude of emissions during spring and fall shoulder seasons, and the growing season in relation to physical and biological conditions. FCH4 was measured using eddy covariance with a closed-path analyser in four years (2008–2011). Cumulative measured annual FCH4 (shoulder plus growing seasons) ranged from 3.0 to 9.6 g CH4 m−2 yr−1 among the four study years, with a mean of 6.5 to 7.1 g CH4 m−2 yr−1 depending upon gap-filling method. Soil temperatures to depths of 50 cm and air temperature were highly correlated with FCH4, with near-surface soil temperature at 5 cm most correlated across spring, fall, and the shoulder and growing seasons. The response of FCH4 to soil temperature at the 5 cm depth and air temperature was more than double in spring to that of fall. Emission episodes were generally not observed during spring thaw. Growing season emissions also depended upon soil and air temperatures but the water table also exerted influence, with FCH4 highest when water was 2–13 cm below and lowest when it was at or above the mean peat surface.


2016 ◽  
Vol 41 (2) ◽  
pp. e12817 ◽  
Author(s):  
Antia Orphanides ◽  
Vlasios Goulas ◽  
George Botsaris ◽  
Vassilis Gekas

2018 ◽  
Vol 42 (4) ◽  
pp. 1222-1232 ◽  
Author(s):  
Henri E. Cuny ◽  
Patrick Fonti ◽  
Cyrille B.K. Rathgeber ◽  
Georg Arx ◽  
Richard L. Peters ◽  
...  

2013 ◽  
Vol 10 (11) ◽  
pp. 7575-7597 ◽  
Author(s):  
K. A. Luus ◽  
Y. Gel ◽  
J. C. Lin ◽  
R. E. J. Kelly ◽  
C. R. Duguay

Abstract. Arctic field studies have indicated that the air temperature, soil moisture and vegetation at a site influence the quantity of snow accumulated, and that snow accumulation can alter growing-season soil moisture and vegetation. Climate change is predicted to bring about warmer air temperatures, greater snow accumulation and northward movements of the shrub and tree lines. Understanding the responses of northern environments to changes in snow and growing-season land surface characteristics requires: (1) insights into the present-day linkages between snow and growing-season land surface characteristics; and (2) the ability to continue to monitor these associations over time across the vast pan-Arctic. The objective of this study was therefore to examine the pan-Arctic (north of 60° N) linkages between two temporally distinct data products created from AMSR-E satellite passive microwave observations: GlobSnow snow water equivalent (SWE), and NTSG growing-season AMSR-E Land Parameters (air temperature, soil moisture and vegetation transmissivity). Due to the complex and interconnected nature of processes determining snow and growing-season land surface characteristics, these associations were analyzed using the modern nonparametric technique of alternating conditional expectations (ACE), as this approach does not impose a predefined analytic form. Findings indicate that regions with lower vegetation transmissivity (more biomass) at the start and end of the growing season tend to accumulate less snow at the start and end of the snow season, possibly due to interception and sublimation. Warmer air temperatures at the start and end of the growing season were associated with diminished snow accumulation at the start and end of the snow season. High latitude sites with warmer mean annual growing-season temperatures tended to accumulate more snow, probably due to the greater availability of water vapor for snow season precipitation at warmer locations. Regions with drier soils preceding snow onset tended to accumulate greater quantities of snow, likely because drier soils freeze faster and more thoroughly than wetter soils. Understanding and continuing to monitor these linkages at the regional scale using the ACE approach can allow insights to be gained into the complex response of Arctic ecosystems to climate-driven shifts in air temperature, vegetation, soil moisture and snow accumulation.


2015 ◽  
Vol 29 (2) ◽  
pp. 129-135 ◽  
Author(s):  
Alina Danielewska ◽  
Marek Urbaniak ◽  
Janusz Olejnik

Abstract The Scots pine is one of the most important species in European and Asian forests. Due to a widespread occurrence of pine forests, their significance in the energy and mass exchange between the Earth surface and the atmosphere is also important, particularly in the context of climate change and greenhouse gases balance. The aim of this work is to present the relationship between the average annual net ecosystem productivity and growing season length, latitude and air temperature (tay) over Europe. Therefore, CO2 flux measurement data from eight European pine dominated forests were used. The observations suggest that there is a correlation between the intensity of CO2 uptake or emission by a forest stand and the above mentioned parameters. Based on the obtained results, all of the selected pine forest stands were CO2 sinks, except a site in northern Finland. The carbon dioxide uptake increased proportionally with the increase of growing season length (9.212 g C m-2 y-1 per day of growing season, R2 = 0.53, p = 0.0399). This dependency showed stronger correlation and higher statistical significance than both relationships between annual net ecosystem productivity and air temperature (R2 = 0.39, p = 0.096) and annual net ecosystem productivity and latitude (R2 = 0.47, p = 0.058). The CO2 emission surpassed assimilation in winter, early spring and late autumn. Moreover, the appearance of late, cold spring and early winter, reduced annual net ecosystem productivity. Therefore, the growing season length can be considered as one of the main factor affecting the annual carbon budget of pine forests.


2012 ◽  
Vol 27 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Nereu Augusto Streck ◽  
Stefanía Dalmolin da Silva ◽  
Josana Andreia Langner

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.


2006 ◽  
Vol 55 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Ferenc Ács ◽  
H. Breuer

The climatology of soil respiration in Hungary is presented. Soil respiration is estimated by a Thornthwaite-based biogeochemical model using soil hydrophysical data and climatological fields of precipitation and air temperature. Soil respiration fields are analyzed for different soil textures (sand, sandy loam, loam, clay loam and clay) and time periods (year, growing season and months).  Strong linear relationships were found between soil respiration and the actual evapotranspiration for annual and growing season time periods. In winter months soil respiration is well correlated with air temperature, while in summer months there is a quite variable relationship with water balance components. The strength of linear relationship between soil respiration and climatic variables is much better for coarser than for finer soil texture.


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

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.  


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