Dormancy and time of bud burst in the sultana vine

1966 ◽  
Vol 17 (1) ◽  
pp. 55 ◽  
Author(s):  
JG Baldwin
Keyword(s):  
Multiple Regression ◽  
Dry Weight ◽  
Field Trials ◽  
Bud Dormancy ◽  
Daily Maximum ◽  
Bud Burst ◽  
Daily Minimum ◽  
Maximum Temperatures

Time of bud burst for sultana vines at Merbein has been closely related to sums of daily temperatures at four periods during bud dormancy by a multiple regression covering 17 years, the result being supported by field trials of vine heating. Bud burst is delayed by higher daily maximum temperatures in May. Higher daily minimum temperatures in late June and in July, or higher daily maximum temperatures in August and until burst, are associated with earlier bud burst. Studies of bud dry weight and moisture have suggested that the change-over between the association of higher daily minimum temperatures and higher daily maximum temperatures with earlier bud burst occurs at a specified sum of degrees by which daily minimum temperatures fall below 50°F, giving dates ranging from July 5 to August 7 for the years of the regression. This appears to be the beginning of imposed dormancy. Use of the regression for predicting time of bud burst is discussed.

The relation between weather and fruitfulness of the sultana vine

1964 ◽  
Vol 15 (6) ◽  
pp. 920 ◽  
Author(s):  
JG Baldwin
Keyword(s):  
Daily Maximum ◽  
Bud Burst ◽  
Confidence Limits ◽  
Two Factors ◽  
The Hours ◽  
Maximum Temperatures

The percentage of fruitful buds on sultanas is shown to be closely related to the weather over 3 weeks in late November and early December mdash; that is, during the period when the inflorescence primordia are differentiated. The two factors concerned are the hours of bright sunshine and the sum of daily maximum temperatures from 82 to 90°F. An estimate of the start of the period for which these weather elements are effective can be made by summing mean temperatures from bud burst. The study covers 18 years, 1945 to 1962 inclusive. Fruitfulness was lower than expected in the first 9 years, and higher in the second 9 years, possibly because of the use of Bordeaux spray in the first period and its replacement by organic sprays in the second. Fruitfulness can be forecast within practical confidence limits from a regression developed for fruitfulness from 1954 to 1962 inclusive on sunshine and maximum temperatures.

scholarly journals Aircraft Takeoff Performance in a Changing Climate for Canadian Airports

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 418
Author(s):  
Yijie Zhao ◽  
Laxmi Sushama
Keyword(s):  
Climate Change ◽  
Climate Model ◽  
Regional Climate ◽  
Daily Maximum ◽  
Daily Minimum ◽  
Weight Restriction ◽  
South Central ◽  
Aircraft Performance ◽  
Maximum Temperatures ◽  
Projected Changes

Temperature and wind are major meteorological factors that affect the takeoff and landing performance of aircraft. Warmer temperatures and the associated decrease in air density in future climate, and changes to crosswind and tailwind, can potentially impact aircraft performance. This study evaluates projected changes to aircraft takeoff performance, in terms of weight restriction days and strong tailwind and crosswind occurrences, for 13 major airports across Canada, for three categories of aircraft used for long-, medium- and short-haul flights. To this end, two five-member ensembles of transient climate change simulations performed with a regional climate model, for Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios, respectively, are analyzed. Results suggest that the projected increases in weight restriction days associated with the increases in daily maximum temperatures vary with aircraft category and airfield location, with larger increases noted for airfields in the south central regions of Canada. Although avoiding takeoff during the warmest period of the day could be a potential solution, analysis focused on the warmest and coolest periods of the day suggests more weight restriction hours even during the coolest period of the day, for these airfields. Though RCP8.5 in general suggests larger changes to weight restriction hours compared to RCP4.5, the differences between the two scenarios are more prominent for the coolest part of the day, as projected changes to daily minimum temperatures occur at a much faster rate for RCP8.5 compared to RCP4.5, and also due to the higher increases in daily minimum temperatures compared to maximum temperatures. Both increases and decreases to crosswind and tailwind are projected, which suggest the need for detailed case studies, especially for those airfields that suggest increases. This study provides useful preliminary insights related to aircraft performance in a warmer climate, which will be beneficial to the aviation sector in developing additional analysis and to support climate change adaptation-related decision-making.

Prediction of temperatures in cattle dung for estimating development times of coprophilous organisms

1988 ◽  
Vol 78 (2) ◽  
pp. 235-240 ◽  
Author(s):  
J. N. Matthiessen ◽  
M. J. Palmer
Keyword(s):  
Air Temperature ◽  
Meteorological Data ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Threshold Temperature ◽  
Cattle Dung ◽  
Daily Maximum ◽  
Daily Minimum ◽  
Maximum Temperatures ◽  
Minimum Air Temperature

AbstractIn studies in Western Australia, temperatures in air and one- and two-litre pads of cattle dung set out weekly and ranging from one to 20 days old were measured hourly for 438 days over all seasons, producing 1437 day x dung-pad observations. Daily maximum temperatures (and hence thermal accumulation) in cattle dung pads could not be accurately predicted using meteorological data alone. An accurate predictor of daily maximum dung temperature, using multiple regression analysis, required measurement of the following factors: maximum air temperature, hours of sunshine, rainfall, a seasonal factor (the day number derived from a linear interpolation of day number from day 0 at the winter solstice to day 182 at the preceding and following summer solstices) and a dung-pad age-specific intercept term, giving an equation that explained a 91·4% of the variation in maximum dung temperature. Daily maximum temperature in two-litre dung pads was 0·6°C cooler than in one-litre pads. Daily minimum dung temperature equalled minimum air temperature, and daily minimum dung temperatures occurred at 05.00 h and maximum temperatures at 14.00 h for one-litre and 14.30 h for two-litre pads. Thus, thermal summation in a dung pad above any threshold temperature can be computed using a skewed sine curve fitted to daily minimum air temperature and the calculated maximum dung temperature.

scholarly journals Association of mortality and warmer weather below heatwave thresholds, in Berlin, Germany, between 2013 and 2015: a retrospective study

2019 ◽  
Vol 69 (suppl 1) ◽  
pp. bjgp19X703661
Author(s):  
Heinz Tilenius
Keyword(s):  
Effect Size ◽  
Secondary Data ◽  
Mortality Rates ◽  
Daily Maximum ◽  
Daily Minimum ◽  
Mortality Effect ◽  
Incidence Risk ◽  
Temperature Ranges ◽  
Maximum Temperatures ◽  
Rate Ratios

BackgroundWhile an association between increased mortality and heatwaves is well known, less is known about higher temperatures ranges below heatwaves and mortality, in urban settings.AimTo establish if there was an association between mortality rates within the population of Berlin, during defined risk periods of daily warmer temperatures between 2013 and 2015.MethodA retrospective secondary data analysis of death counts, population, and temperature data from Berlin. A defined risk periods model of specified temperature ranges of daily minimum and daily maximum temperatures investigated May to September, from 2013 to 2015. A Poisson regression model established incidence rate ratios (IRRs) for mortality. Effect size was estimated in ‘lives lost’.ResultsMortality rates were noticeably increased during defined risk periods for all people aged ≥65 years during daily temperatures of ≥18 to ≤29°C. In people aged ≥75–84 years, during risk period ≥18°C to ≤29°C, incidence risk ratio (IRR) was 1.22 (95% confidence interval [CI] = 1.07 to 1.40, P = 0.004). For females aged 65–74 years, during ≥18°C to ≤29°C, a higher mortality rate was found, compared to males (females: IRR 1.28, 95% CI = 1.15 to 1.42, P<0.001; males: IRR 0.93, 95% CI = 0.78 to 1.10, P = 0.390). Effect size calculation estimated an additional 252 deaths in Berlin, between 2013 and 2015, with 133 deaths in the ≥85-year group.ConclusionAs mortality of older people increased during defined warmer weather, temperatures below heatwave ranges need acknowledgement as a risk factor for health. Policies and health warning systems should include daily minimum temperatures.

scholarly journals Evaluation of Infilling Methods for Time Series of Daily Temperature Data: Case Study of Limpopo Province, South Africa

Climate ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 86 ◽  
Author(s):  
Zakhele Phumlani Shabalala ◽  
Mokhele Edmond Moeletsi ◽  
Mphethe Isaac Tongwane ◽  
Sabelo Marvin Mazibuko
Keyword(s):  
South Africa ◽  
Multiple Regression ◽  
Limpopo Province ◽  
Maximum Temperature ◽  
Mean Bias Error ◽  
Climate Data ◽  
Daily Minimum ◽  
Normal Ratio ◽  
Maximum Temperatures ◽  
Inverse Distance

Incomplete climate records pose a major challenge to decision makers that utilize climate data as one of their main inputs. In this study, different climate data infilling methods (arithmetic averaging, inverse distance weighting, UK traditional, normal ratio and multiple regression) were evaluated against measured daily minimum and maximum temperatures. Eight target stations that are evenly distributed in Limpopo province, South Africa, were used. The objective was to recommend the best approach that results in lowest errors. The optimum number of buddy/neighboring weather stations required for best estimate for each of the approaches was determined. The evaluation indices employed in this study were the correlation coefficient (r), mean absolute error (MAE), root mean square error (RMSE), accuracy rate (AR) and mean bias error (MBE). The results showed high correlation (r > 0.92) for all the stations, different methods and varying number of neighboring stations utilised. The MAE [RMSE] for the best performing methods (multiple regression and UK traditional) of estimating daily minimum temperature and maximum temperature was less than 1.8 °C [2.3 °C] and 1.0 °C [1.6 °C], respectively. The AR technique showed the MR method as the best approach of estimating daily minimum and maximum temperatures. The other recommended methods are the UK traditional and normal ratio. The MBEs for the arithmetic averaging and inverse-distance weighing techniques are large, indicating either over- or underestimating of the air temperature in the province. Based on the low values for the error estimating statistics, these data infilling methods for daily minimum and maximum air temperatures using neighboring stations data can be utilised to complete the datasets that are used in various applications.

scholarly journals Impact of Aligning Climatological Day on Gridding Daily Maximum–Minimum Temperature and Precipitation over Canada

2011 ◽  
Vol 50 (8) ◽  
pp. 1654-1665 ◽  
Author(s):  
Ron F. Hopkinson ◽  
Daniel W. McKenney ◽  
Ewa J. Milewska ◽  
Michael F. Hutchinson ◽  
Pia Papadopol ◽  
...  
Keyword(s):  
Minimum Temperature ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Daily Minimum ◽  
Temperature And Precipitation ◽  
Daily Data ◽  
National University ◽  
Maximum Temperatures

AbstractOn 1 July 1961, the climatological day was redefined to end at 0600 UTC at all principal climate stations in Canada. Prior to that, the climatological day at principal stations ended at 1200 UTC for maximum temperature and precipitation and 0000 UTC for minimum temperature and was similar to the climatological day at ordinary stations. Hutchinson et al. reported occasional larger-than-expected residuals at 50 withheld stations when the Australian National University Spline (ANUSPLIN) interpolation scheme was applied to daily data for 1961–2003, and it was suggested that these larger residuals were in part due to the existence of different climatological days. In this study, daily minimum and maximum temperatures at principal stations were estimated using hourly temperatures for the same climatological day as local ordinary climate stations for the period 1953–2007. Daily precipitation was estimated at principal stations using synoptic precipitation data for the climatological day ending at 1200 UTC, which, for much of the country, was close to the time of the morning observation at ordinary climate stations. At withheld principal stations, the climatological-day adjustments led to the virtual elimination of large residuals in maximum and minimum temperature and a marked reduction in precipitation residuals. Across all 50 withheld stations the climatological day adjustments led to significant reductions, by around 12% for daily maximum temperature, 15% for daily minimum temperature, and 22% for precipitation, in the residuals reported by Hutchinson et al.

scholarly journals Bias in Minimum Temperature Introduced by a Redefinition of the Climatological Day at the Canadian Synoptic Stations

2009 ◽  
Vol 48 (10) ◽  
pp. 2160-2168 ◽  
Author(s):  
Lucie A. Vincent ◽  
Ewa J. Milewska ◽  
Ron Hopkinson ◽  
Leslie Malone
Keyword(s):  
Spatial Variation ◽  
Minimum Temperature ◽  
Universal Time ◽  
Maximum Temperature ◽  
Daily Maximum ◽  
Cold Bias ◽  
The West ◽  
Daily Minimum ◽  
Maximum Temperatures ◽  
The Impact

Abstract On 1 July 1961, the climatological day was redefined to end at 0600 UTC (coordinated universal time) at all synoptic (airport) stations in Canada. Prior to that, the climatological day ended at 1200 UTC for maximum temperature and 0000 UTC for minimum temperature. This study shows that the redefinition of the climatological day in 1961 has created a cold bias in the annual and seasonal means of daily minimum temperatures across the country while the means of daily maximum temperatures were not affected. Hourly temperatures taken at 121 stations for 1953–2007 are used to determine the magnitude of the bias and its spatial variation. It was found that the bias is more pronounced in the eastern regions; its annual mean varies from −0.2° in the west to −0.8°C in the east. Not all days are affected by this change in observing time, and the annual percentage of affected days ranges from 15% for locations in the west to 38% for locations in the east. An approach based on hourly values is proposed for adjusting the affected daily minimum temperatures over 1961–2007. The adjustment on any individual day varies from 0.5° to 12.5°C. The impact of the adjustment is assessed by examining the trends in the annual mean of the daily minimum temperatures for 1950–2007. Overall, with the adjustment, the trends are becoming either more positive or are reversing from negative to positive, and they have changed by as much as 1°C in numerous locations in the eastern regions.

scholarly journals Temperature-related climate extremes in the Potsdam observation record

Geografie ◽  
2008 ◽  
Vol 113 (4) ◽  
pp. 372-382
Author(s):  
Zbigniew W. Kundzewicz ◽  
Damian Józefczyk
Keyword(s):  
Climate Extremes ◽  
Daily Temperature ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Maximum Daily Temperature ◽  
Daily Minimum ◽  
Maximum Temperatures ◽  
Minimum Daily Temperature

This paper examines temperature-related climate extremes in the unique long-term gapfree record at the Secular Meteorological Station in Potsdam. Increasing tendencies in daily minimum temperature in winter and daily maximum temperature in summer, as well as monthly means of daily minimum temperatures in winter months and of daily maximum temperatures in summer months are illustrated. Also the numbers of hot days and of summer days (with maximum daily temperature exceeding 30 °C and 25 °C, respectively) have been increasing. In agreement with warming of winter minimum temperatures, the numbers of frost days (with minimum daily temperature below 0 °C) and of ice days (with maximum daily temperature below 0 °C) have been decreasing. However, low correlation coefficient and huge scatter illustrate strong natural variability, so that the occurrence of extremes departs from the general underlying tendency.

Comparative Effect of Groundnut (Arachis hypogea l.) Genotypes on Yield and N Fixation in Sudan and Northern Guinea Savannahs of Nigeria

2019 ◽  
pp. 61-67
Keyword(s):  
Agricultural Research ◽  
Cropping Systems ◽  
Block Design ◽  
Dry Weight ◽  
Field Trials ◽  
Yield Potential ◽  
N Fixation ◽  
Maize Crop ◽  
Significant Interaction Effect ◽  
Pod Yield

Recognition of high yielding and nitrogen (N) fixing groundnut genotypes and desegregating them in the cereal-based cropping systems common in savannah regions will enhance food security and reduce the need for high N fertilizers hence, minimize the high cost and associated environmental consequences. Field trials were conducted during the 2015 growing season at the Research Farms of Bayero University Kano (BUK) and Institute for Agricultural Research (IAR), Ahmadu Bello University, Samaru-Zaria to assess the yield potential and Biolog- ical N fixation in 15 groundnut genotypes (ICG 4729, ICGV-IS 07823, ICGV-IS 07893, ICGV-IS 07908, ICGV- SM 07539, ICGV- SM 07599, ICGV-IS 09926, ICGV-IS 09932, ICGV-IS 09992, ICGV-IS 09994, SAMNUT-21, SAMNUT-22, SAMNUT-25, KAMPALA and KWANKWAS). The groundnut genotypes and reference Maize crop (SAMMAZ 29) were planted in a randomized complete block design in three replications. N difference method was used to estimate the amount of N fixed. The parameters determined were the number of nodules, nod- ule dry weight, shoot and root dry weights, pod, and haulm yield as well as N fixation. The nodule dry weight, BNF, haulm, and pod yield were statistically significant (P<0.01) concerning genotype and location. Similarly, their interac- tion effect was also highly significant. ICGV-IS 09926 recorded the highest nod- ule dry weight of 2.07mg /plant across the locations while ICGV-IS 09932 had the highest BNF value of 140.27Kg/ha. Additionally, KAMPALA had the high- est haulm yield, while ICGV-IS 07893 had the highest pod yield across the loca- tions with a significant interaction effect. The result shows that ICGV-IS 07893 and ICGV-IS 09932, as well as ICGV-IS 09994 and SAMNUT – 22, were the best genotypes concerning BNF, haulm and pod yield in the Northern Guinea and Sudan Savannahs of Nigeria respectively with the potential for a corresponding beneficial effect.

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