An analysis of yearly trends in growing degree days and the relationship between growing degree day values and reference evapotranspiration in Turpan area, China

2012 ◽  
Vol 113 (3-4) ◽  
pp. 711-724 ◽  
Author(s):  
Lijun Su ◽  
Quanjiu Wang ◽  
Yungang Bai
Keyword(s):  
Reference Evapotranspiration ◽  
Growing Degree Days ◽  
Degree Days ◽  
Degree Day ◽  
The Relationship

Effect of weather station logging interval on the precision of degree-day estimates

1995 ◽  
Vol 35 (6) ◽  
pp. 795 ◽  
Author(s):  
DM Watson ◽  
GAC Beattie
Keyword(s):  
Weather Station ◽  
Data Logging ◽  
Degree Days ◽  
Degree Day ◽  
The Relationship

The relationship between data-logging intervals and degree-day estimates was examined to determine the longest interval giving equivalent information to estimates based on 12-min intervals and, so, the most efficient interval for estimation of degree-days

Relationships among growing degree-days, tenderness, other harvest attributes and market value of processing pea (Pisum sativum L.) cultivars grown in Quebec

2006 ◽  
Vol 86 (2) ◽  
pp. 525-537 ◽  
Author(s):  
Edith Fallon, Nicolas Tremblay ◽  
Yves Desjardins
Keyword(s):  
Moisture Content ◽  
Size Distribution ◽  
Seed Size ◽  
Growing Degree Days ◽  
Harvest Time ◽  
Degree Days ◽  
Fresh Matter ◽  
Yield And Quality ◽  
Grain Moisture ◽  
The Relationship

In Quebec, grower income from processing peas is a function of yield and tenderometer reading. If peas are harvested early, the yield is poor, but the overall quality is superior, as indicated by lower tenderometer readings. Later harvests result in g reater yields but reduced quality (higher tenderometer readings). A better understanding of the relationship between harvest time, yield and quality is needed. In this study, the relationships between yield, tenderometer readings, size distribution and grain moisture content were examined as a function of growing degree-days (GDD) and production year for pea cultivars of different seed size categories. Yield and harvest attributes (tenderometer readings, seed size distribution and moisture content) were highly season dependent and their rates of change over the course of the harvest period also varied with the cultivar and year. Quality declined rapidly once the crop reached optimal maturity, while yield increased in a less predictable manner. Consequently, it was difficult to identify a harvest time that would consistently maximize grower returns. The highest income was generally not obtained at the optimal tenderometer readings presently used by the industry. Key words: Maturity, harvest date, climate, fresh matter yield, tenderometer, pea size

scholarly journals Effect of cumulative growing degree day on accumulation of alfalfa (Medicago sativa L.) root reserve saccharides

2008 ◽  
Vol 56 (2) ◽  
pp. 81-86
Author(s):  
Josef Hakl ◽  
Jaromír Šantrůček ◽  
Pavel Fuksa ◽  
Josef Kalista
Keyword(s):  
Medicago Sativa ◽  
Starch Content ◽  
Life Sciences ◽  
Vegetation Period ◽  
Water Soluble ◽  
Research Station ◽  
Growing Degree Days ◽  
Degree Days ◽  
Degree Day ◽  
Medicago Sativa L

The aim of this study was to investigate the relation between growing degree day method and accumulation of root reserve saccharides before over wintering by alfalfa (Medicago sativa L.) in the condition of Czech Republic. In 2002–2004, the field experiment was conducted at the Research station of the Czech University of Life Sciences in central Bohemia. The interval between summer and last autumn harvest was 40–50 days or 60–70 days, respectively. These intervals were expressed as cumulative growing degree-days (GDD) for each year. The plants were sampled in each autumn with four replicates for each variant; the average depth of sampling was 150 mm. The weight of roots, amount of starch, and water soluble saccharides (WSC) per m2 was determined. The total accumulation of root reserve saccharides was determined mainly by conditions during all vegetation period. The length of the interval or cumulative GDD influenced only variation of this basic amount. The GDD was corresponded better with starch content whilst WSC was more related to length of the interval. In central Bohemia condition, the GDD 600–700 °C was preliminary determined for maximal accumulation of root reserve saccharides. The GDD above this level did not significantly increase the root reserve accumulation. For exact verify of this model, other experiments in more sites are needed.

scholarly journals Improving the Prediction of Processing Bean Maturity Based on the Growing-degree Day Approach

HortScience ◽  
2000 ◽  
Vol 35 (7) ◽  
pp. 1234-1237 ◽  
Author(s):  
Sylvie Jenni ◽  
Gaétan Bourgeois ◽  
Hélène Laurence ◽  
Geneviève Roy ◽  
Nicolas Tremblay
Keyword(s):  
Phaseolus Vulgaris ◽  
Prediction Model ◽  
Coefficient Of Variation ◽  
Developmental Stages ◽  
Growing Degree Days ◽  
Base Temperature ◽  
Degree Days ◽  
Snap Bean ◽  
Degree Day ◽  
Common Base

Four snap bean (Phaseolus vulgaris L.) cultivars, Goldrush, Teseo, Labrador, and Flevoro, were grown in irrigated fields of southern Quebec between 1985 and 1998. Data on phenology collected from these fields were used to determine which base temperature would best predict time from sowing to maturity. The optimal base temperature was 0 °C for `Goldrush', `Teseo', and `Labrador' and 6.7 °C for `Flevoro'. Adjusting different base temperatures for intermediate developmental stages (emergence, flowering) did not improve the prediction model. All years for a given cultivar were then used to determine the base temperature with the lowest coefficient of variation (CV) for predicting the time from sowing to maturity. A common base temperature of 0 °C was selected for all cultivars, since `Flevoro' was not very sensitive to changes in base temperature. This method improved the prediction of maturity compared with the conventional computation growing-degree days (GDD) with a base of 10 °C. For the years and cultivars used in this study, calculating GDD with a base of 0 °C gave an overall prediction of maturity of 1.7, 1.5, 2.0, and 1.4 days based on average absolute differences, for `Flevoro', `Goldrush', `Teseo', and `Labrador', respectively.

scholarly journals Growing Degree-day Requirements for Scheduling Flowering of Scadoxus multiflorus subsp. katharinae (Baker) Friis & Nordal

HortScience ◽  
2008 ◽  
Vol 43 (1) ◽  
pp. 166-169 ◽  
Author(s):  
Keith A. Funnell
Keyword(s):  
Cold Storage ◽  
Growing Degree Days ◽  
Base Temperature ◽  
Leaf Lamina ◽  
Degree Days ◽  
Vegetative Shoot ◽  
Degree Day

Containerized plants of Scadoxus multiflorus subsp. katharinae (Baker) Friis & Nordal were forced to anthesis under three environments of contrasting temperature. Flowering performance, growing degree-days (GDD) requirements for timing of anthesis, and the influence of cold storage (12 °C for 4 weeks) before forcing were evaluated. Total forcing time from the beginning of the experiment until anthesis decreased with warmer forcing environment, ranging between 129 and 86 days. Across all forcing environments, use of GDD was readily able to explain differences in time to anthesis resulting from both cold storage and forcing. Using a base temperature of 5 °C, GDD requirements between beginning of the experiment and anthesis was 1166 ± 124 GDD, emergence of the vegetative shoot and anthesis 1075 ± 118 GDD, and appearance of the tips of the leaf lamina and anthesis 883 ± 91 GDD. Using a base temperature of 11.5 °C, GDD requirements between appearance of tip of the involucre and anthesis was 180 ± 44 GDD, and the whole involucre being visible and anthesis 144 ± 42 GDD. In the next year, validation of the GDD requirements was achieved by subsequently forcing a second population of plants to anthesis for a specific date.

Predicting Yellow Nutsedge (Cyperus esculentus) Emergence Using Degree-day Models

Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 821-829 ◽  
Author(s):  
Cheryl A. Wilen ◽  
Jodie S. Holt ◽  
William B. McCloskey
Keyword(s):  
United States ◽  
Predictive Models ◽  
Field Experiments ◽  
Temperature Data ◽  
Cyperus Esculentus ◽  
Degree Days ◽  
Model Accuracy ◽  
Yellow Nutsedge ◽  
Degree Day ◽  
The Relationship

We examined the relationship between temperature and emergence of yellow nutsedge tubers to generate predictive models for the arid southwestern United States. Field experiments were conducted in California and Arizona to obtain phenological and temperature data needed to generate degree-day models. The effect of air temperature on emergence was tested with available programs using four methods to calculate degree-days (single sine, double sine, single triangle, and double triangle). Separate models were tested for each genotype examined (Arizona source and California source) as no one model was a good predictor of emergence when data were pooled. Results indicate that there is year to year variation in model accuracy but predictions of date of emergence can be made to within 2 d of actual emergence. This information can be used to schedule cultivations to reduce early yellow nutsedge competition in the field.

Leaf appearance rate of summer rape

1991 ◽  
Vol 71 (2) ◽  
pp. 405-412 ◽  
Author(s):  
M. J. Morrison ◽  
P. B. E. McVetty
Keyword(s):  
Leaf Number ◽  
Growing Degree Days ◽  
Linear Regression Equation ◽  
Degree Days ◽  
Mean Temperature ◽  
Appearance Rate ◽  
Leaf Appearance Rate ◽  
Number Of Leaves ◽  
Leaf Appearance ◽  
The Relationship

Leaf appearance rate (LAR) is defined as the slope of the regression of leaf number on time of appearance. LARs were calculated for summer rape using both calendar days (CD) and growing degree days (GDD) as measurements of time. The relationship between the number of leaves and GDD or CD was linear. LARs after emergence were 0.022 leaves GDD−1 or 0.247 leaves d−1. Summer rape was grown in growth cabinets set at different mean temperatures to study the effect of air temperature on LAR. The relationship between leaf number and time was linear. When CD were used as a measure of time, LAR increased as mean temperature increased, while the reverse was true when GDD were used to measure time. Cabinet and field LARs were compared at a field mean temperature of 16.5 °C. Cabinet LARs were 0.021 leaves GDD−1 or 0.22 leaves CD−1 which were similar to those calculated in the field. The linear regression equation describing the relationship between LAR (leaves GDD−1) and mean cabinet temperature was used with field-measured daily mean temperatures and GDD to predict the number of leaves for field conditions. When observed number of leaves were plotted against predicted number of leaves, the resulting slope was not significantly different from one, indicating that the model developed in the growth cabinet can be used to predict LAR in the field. Key words: Leaf appearance rate, Brassica napus, phyllochron

scholarly journals Analysis of multi peril crop insurance loss ratiosAnalysis of multi peril crop insurance loss ratios

2010 ◽  
Vol 51 ◽  
Author(s):  
Lina Žalgirytė ◽  
Gediminas Račkauskas
Keyword(s):  
Pareto Distribution ◽  
Crop Insurance ◽  
Weather Conditions ◽  
Growing Degree Days ◽  
Monthly Precipitation ◽  
Degree Days ◽  
The Relationship

In the first part of this paper, the distribution of loss ratios for five crops was analyzed. The results show that the truncated shifted Pareto distribution can be used for crop insurance loss ratios approximation. In the second part, the relationship between weather conditions and crop insurance loss ratios was tested. Results suggest that this dependency is weak. It shows that crop insurance loss ratios are affected not only by weather conditions – monthly growing degree days and monthly precipitation – but also by other factors.

scholarly journals Relationship between agro-ecological resources of vineyards and the anthocyanins complex in berries

2021 ◽  
Vol 247 ◽  
pp. 01013
Author(s):  
Elena Ostroukhova ◽  
Evgeniy Rybalko ◽  
Svetlana Levchenko ◽  
Vladimir Boyko ◽  
Dmitriy Belash ◽  
...  
Keyword(s):  
Inverse Correlation ◽  
Cabernet Sauvignon ◽  
Growing Degree Days ◽  
Red Wines ◽  
Degree Days ◽  
Natural Region ◽  
Ecological Resources ◽  
Heat And Moisture ◽  
The Relationship ◽  
Western Foothill

This article is aimed at identifying the relationship between the territories agro-ecological conditions and the anthocyanins complex formation of grapes, which determines the quality and biological value of red wines. Using HPLC, the anthocyanins complex of 'Cabernet Sauvignon' cultivar from 6 industrial vineyards, located in three natural regions of Crimea, was studied. The agro-climatic resources of vineyards were assessed using the methods of geoinformation and mathematical modeling. It was detected that according to parameters of heat and moisture supply vineyards discriminated with Wilks L. = 0.007; α<0.00001. The direct correlation (r = 0.88-0.95) was identified between growing degree days above 10 °C, growing degree days above 20 °C, Winkler index, average growing season temperature and the rate of monoglucosides of malvidin and its derivatives in anthocyanins complex of berries; the inverse correlation – between the same agroecological indexes and the rate of cyanidin, petunidin and their derivatives. The similarity (Ed = 2.79-2.98) of anthocyanins complex of grapes from Villino v., Uglovoe v. and Yalta t. located in the western foothill-coastal and south coast regions was discovered. The highest content of anthocyanins was found in grapes from Privetnoe v. (5487 ± 384 mg kg-1), the smallest - from Solnechnaya Dolina v. (2154 ± 129 mg kg-1) located in the same natural region. The results obtained indicate the need for a "point" assessment of the agro-ecological resources for creation of industrial vineyards.

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