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

HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 611-614 ◽  
Author(s):  
Gaétan Bourgeois ◽  
Sylvie Jenni ◽  
Hélène Laurence ◽  
Nicolas Tremblay
Keyword(s):  
Current Model ◽  
Climatic Conditions ◽  
Developmental Period ◽  
Temperature Data ◽  
Growing Degree Days ◽  
Base Temperature ◽  
Degree Days ◽  
Planting Dates ◽  
Average Temperature ◽  
Unit System

The heat-unit system, involving the sum of daily mean temperatures above a given base temperature, is used with processing pea (Pisum sativum L.) to predict relative maturity during the growing season and to schedule planting dates based on average temperature data. The Quebec pea processing industry uses a base temperature of 5 °C to compute growing-degree days (GDD) between sowing and maturity. This study was initiated to verify if the current model, which uses a base temperature of 5 °C, can be improved to predict maturity in Quebec. Four pea cultivars, `Bolero', `Rally', `Flair', and `Kriter', were grown between 1985 and 1997 on an experimental farm in Quebec. For all cultivars, when using a limited number of years, a base temperature between 0.0 and 0.8 °C reduced the coefficient of variation (cv) as compared with 5.0 °C, indicating that the base temperature used commercially is probably not the most appropriate for Quebec climatic conditions. The division of the developmental period into different stages (sowing until emergence, emergence until flowering, and flowering until maturity) was also investigated for some years. Use of base temperatures specific for each crop phase did not improve the prediction of maturity when compared with the use of an overall base temperature. All years for a given cultivar were then used to determine the base temperature with the lowest cv for predicting the time from sowing to maturity. A base temperature from 0 to 5 °C was generally adequate for all cultivars, and a common base temperature of 3.0 °C was selected for all cultivars. For the years and cultivars used in this study, the computation of GDD with a base temperature of 3 °C gave an overall prediction of maturity of 2.0, 2.4, 2.2, and 2.5 days based on the average of the absolute values of the differences for the cultivars Bolero, Rally, Flair, and Kriter, respectively.

scholarly journals Phenology, reproductive biology and growing degree days of the grapevine ‘Isabel’ (Vitis labrusca, Vitaceae) cultivated in northeastern Brazil

2016 ◽  
Vol 76 (4) ◽  
pp. 975-982 ◽  
Author(s):  
N. A. S. Nunes ◽  
A. V. Leite ◽  
C. C. Castro
Keyword(s):  
Reproductive Biology ◽  
Pollen Viability ◽  
Floral Biology ◽  
Climatic Conditions ◽  
Northeastern Brazil ◽  
Growing Degree Days ◽  
Base Temperature ◽  
Vitis Labrusca ◽  
Degree Days ◽  
Inflorescence Development

Abstract Phenology and reproductive biology of cultivated species are important for the comprehension of the requirements for fruit and seed production and the management of pollinators. This study aimed to characterise the phenology, reproductive biology and growing degree days of the grapevine ‘Isabel’ (Vitis labrusca) in northeastern Brazil during January 2011 (P1), Augst 2011 (P2), April 2012 (P3) and August 2012 (P4). We recorded the duration (days) of the phenological stages, pruning (P), woolly bud (W), budburst (B), inflorescence development (ID), flowering (F), ripening (R) and harvest (H). We analysed the floral biology, the sexual system and the breeding system. We measured the growing degree days (GDD) required to reach the subperiods P-B, B-F and F-H. The periods P1, P2, P3 and P4 lasted for 116, 125, 117 and 130 days, respectively. The number of days of harvest were similar in the same dry (P1 and P3) and rainy (P2 and P4) periods. All the periods that we recorded were shorter than those observed in other regions of Brazil, which may be attributable to the mean temperature and carbohydrate metabolism. The flowers are green, hermaphroditic, with an odour of mignonette, low pollen viability and autogamous. The base temperature of 10°C was considered the most adequate for the subperiods as has been documented for other grape varieties in Brazil. Thus, temperature was also the most adequate for the cycles, presenting a smaller standard deviation (0.119, 0.147, 0.156 and 0.153 to P1, P2, P3 and P4, respectively) when compared to a base temperature of 12°C (0.122, 0.158, 0.165 and 0.160 to P1, P2, P3 and P4, respectively). The higher and the lower observed GDD were 1972.17 and 1870.05, respectively, both above the values recorded in other parts of Brazil for same variety. The phonological results, including knowledge of growing degree days, are important to the planning of cultures at the study site and in other regions that have similar climatic conditions and make it possible to pre-determine the harvest.

scholarly journals Use of Belowground Growing Degree Days to Predict Rooting of Dormant Hardwood Cuttings of Populus

2004 ◽  
Vol 53 (1-6) ◽  
pp. 154-160 ◽  
Author(s):  
R. S. Zalesny ◽  
E. O. Bauer ◽  
D. E. Riemenschneider
Keyword(s):  
Populus Deltoides ◽  
Dry Weight ◽  
Growing Degree Days ◽  
Base Temperature ◽  
Degree Days ◽  
Planting Dates ◽  
Growing Period ◽  
Period 2 ◽  
Soil Temperatures ◽  
Total Dry Weight

Abstract Planting Populus cuttings based on calendar days neglects soil temperature extremes and does not promote rooting based on specific genotypes. Our objectives were to: 1) test the biological efficacy of a thermal index based on belowground growing degree days (GDD) across the growing period, 2) test for interactions between belowground GDD and clones, and 3) identify beneficial planting windows based on combinations of genotypes and belowground GDD. We tested two clones of Populus deltoides Bartr. ex Marsh (D133, D134) and four hybrid clones of P. deltoides × P. maximowiczii A. Henry (DM101, DM105, NC14105, NC14107). Cuttings, 20 cm long, were planted in randomized complete blocks at 15- × 15-cm spacing across three planting dates during 1999 at Alexandria, Minnesota, USA (45.9°N, 95.4°W) and Fertile, Minnesota, USA (47.3°N, 96.2°W). Temperatures at 20 cm belowground were converted to GDD with a base temperature of 10°C. We measured root, top, and total dry weight, along with number of roots after 14 d of growth. Relatively warmer and cooler soil temperatures promoted rooting for the cottonwoods and hybrids, respectively. We recommend planting after reaching a threshold of 163 belowground GDD for P. deltoides clones and planting before reaching a threshold of 173 belowground GDD for P. deltoides × P. maximowiczii clones.

Effects of thermal model and base temperature on estimates of thermal time to bud break in white spruce seedlings

2010 ◽  
Vol 40 (9) ◽  
pp. 1815-1820 ◽  
Author(s):  
Rongzhou Man ◽  
Pengxin Lu
Keyword(s):  
White Spruce ◽  
Climatic Conditions ◽  
Thermal Time ◽  
Growing Degree Days ◽  
Base Temperature ◽  
Bud Break ◽  
Bud Burst ◽  
Degree Days ◽  
Growing Degree Hours ◽  
Time Requirements

To improve the predictability of bud burst and growth of boreal trees under varying climate, the thermal time for bud break in white spruce ( Picea glauca (Moench) Voss) seedlings was evaluated under a range of temperature conditions in controlled environment chambers. Thermal time requirements were calculated as the sum of growing degree days or growing degree hours above base temperatures ranging from –1 to 5 °C. The results indicated that the common modeling approach, which uses a high base temperature of 5 °C and growing degree days, may not be appropriate for future climatic conditions. Estimates of thermal time requirements using a base temperature of 5 °C varied considerably among temperature treatments and thus would reduce the predictability of bud burst under changing climate. In contrast, estimates of thermal time requirements with lower temperatures closer to 1 °C were relatively consistent among treatments. Growing degree hour models were less sensitive to base temperature than degree day models. These results should help in the selection of appropriate base temperatures and thermal time models in quantification of thermal time for bud burst modeling in other boreal trees.

scholarly journals Spatial Soil Temperature and Moisture Monitoring Across the Transylvanian Plain in Romania

2010 ◽  
Vol 67 (1) ◽  
Author(s):  
Beatrix HAGGARD ◽  
Teodor RUSU ◽  
David WEINDORF ◽  
Horea CACOVEAN ◽  
Paula MORARU ◽  
...  
Keyword(s):  
Best Management Practices ◽  
Management Practices ◽  
Spline Interpolation ◽  
Planting Date ◽  
Growing Degree Days ◽  
Base Temperature ◽  
Degree Days ◽  
Corn Hybrids ◽  
Important Region ◽  
Soil Temperatures

The Transylvanian Plain, Romania is an important region for agronomic productivity. However, limited soils data and adoption of best management practices hinder land productivity. Soil temperatures of the Transylvanian Plain were evaluated using a set of twenty datalogging stations positioned throughout the plain. Soil temperatures were monitored at the surface and at 10, 30, and 50 cm depths, and soil moisture was monitored at 10 cm. Preliminary results indicate that most soils of the Transylvanian Plain will have a mesic temperature regime. However, differences in seasonal warming and cooling trends across the plain were noted. These have important implications for planting recommendations. Growing degree days (GDDs) are preferred over maturity ratings, because they can account for temperature anomalies. The crop being considered for this study was corn. The base temperature (BT) was set at 10oC, and the upper threshold was 30oC. Two methods were used to calculate GDDs; 1) minimum and maximum daily temperatures, and 2) 24 h of averaged temperature data. Growing degree days were run from 110-199 day of year (DOY) to represent approximate planting date to tasseling. The DOY that 694 accumulated growing degree days (AGDDs) was reached at each site was then analyzed to identify differences across the TP. Three sites failed to reach 694 AGDDs by DOY 199, and were excluded from comparisons to other results. Averaged values were used to create spline interpolation maps with ArcMap 9.2 (ESRI, Redlands, CA, USA). The southeastern portion of the TP was found to tassel a month earlier assuming a planting date of 109 DOY. Four DeKalb® corn hybrids were then selected based on GDDs to tasseling, drydown, drought tolerance, and insect resistance. With a better understanding of the GDD trends across the TP, more effective planting and harvesting could be accomplished by Romanian farmers to maximize agronomic production.

Studies on Determination of Critical Growing Degree Days, Base Temperature (Tb) and Response of Temperature Variations on Flowering and Yield per se in Cowpea [Vigna unguiculata (L.) Walp.]

2020 ◽  
Author(s):  
Venkatesh Bondade ◽  
Sanjeev K Deshpande
Keyword(s):  
Dry Matter ◽  
Significant Negative Correlation ◽  
Growing Degree Days ◽  
Base Temperature ◽  
Degree Days ◽  
Temperature Variations ◽  
Days To Flowering ◽  
Matter Production ◽  
Flowering Initiation

Growing degree days (GDD) or heat units accumulation is the major factor that affects the dry matter production in the plants. In the present investigation eleven genotypes were used to screen for temperature insensitivity through staggered plantings across the seasons in a year. Days to flowering initiation was recorded and base temperature (Tb) was determined using mean daily air temperature (MAT). GDD of individual genotypes was estimated using base temperatures of particular genotypes. It was observed that the GDD, days to flowering initiation and yield were exhibited high variation across the seasons, the flowering time from days to planting (FTDAP) registered significant negative correlation with GDD and MAT and positively correlated with yield. Whereas GDD is positively correlated with MAT and negatively correlated with yield. Here three genotypes namely, IC202926, IC198326 and IC257428 were identified as temperature insensitive genotypes as their performances were comparable across the seasons without much fluctuations.

scholarly journals BASE GROWTH TEMPERATURE AND PHYLLOCHRON FOR KIKUYU GRASS (Cenchrus clandestinus; Poaceae)

2021 ◽  
Vol 26 (2) ◽  
pp. 160-169
Author(s):  
Ruth Amanda Acero Camelo ◽  
Manuel Ricardo Esteban Molina ◽  
Alfonso Parra Coronado ◽  
Gerhard Fischer ◽  
Juan Evangelista Carulla Fornaguera
Keyword(s):  
Cross Validation ◽  
Growth Models ◽  
Variation Method ◽  
Growing Degree Days ◽  
Base Temperature ◽  
Degree Days ◽  
Leaf Stage ◽  
Kikuyu Grass ◽  
Predicted Values ◽  
Made In

In order to estimate the base temperature (Bt) of growth through the appearance of leaves and calculate the phyllochron for kikuyu grass, three plots were established on three farms in the Provincia of Ubaté (Cundinamarca, Colombia) located at different altitudes (2560, 2640, 3143 m. a. s. l.). Measurements were made in four cycles in a period of eight months. The Bt was estimated by the least coefficient of variation method using a second order regression model and the model obtained was validated by the cross-validation method. The Bt values for the first, second, third and fourth leaf were 4.02, 3.68, 3.93, and 3.62 ° C, respectively. For the appearance of the first leaf, the kikuyu required more thermal time (TT) (97.5 accumulated growing degree days (AGDD)) than for the second (74.2 AGDD), third (73.8 AGDD) and fourth leaf (76.0 AGDD) (p<0.05). There were no differences in TT among farms (p> 0.05). There was a tendency to a greater number of days required to reach each leaf stage in the farm located at higher altitude and with lower mean temperature. The validation showed an adequate adjustment (r2 = 0.94) and a substantial concordance (CCC = 0.97) between the observed values and the predicted values for the estimated TT with the Bt value obtained for each leaf stage. The results of Bt for kikuyu grass obtained, will allow to make more precise predictions about the phyllochron and generate growth models close to reality.

scholarly journals Selection of high-yielding varieties and hybrids of pan patty squash, determining their most favorable planting dates

2021 ◽  
Vol 258 ◽  
pp. 04024
Author(s):  
Shavkat Durkhodjaev ◽  
Sohibjon Islamov ◽  
Tulganoy Kenjaeva ◽  
Abdulaziz Tojiboyev
Keyword(s):  
Seed Germination ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
High Yield ◽  
Planting Dates ◽  
Average Temperature ◽  
The Family ◽  
High Yielding Varieties ◽  
One Year ◽  
The Impact

In this article, the results of research on the cultivation of patty pan squash in the climatic conditions of Uzbekistan, Planting for different periods and its growth, development, yield, as well as the impact of weather conditions were presented. Squash is a one-year plant of the family of zucchini, mainly shrub, rarely found in the form of a whip. The results showed that average yield of “White-13” control was 16 tons/ha, and it was 17 tons/ha in “Solnyshko”. Furthermore, “NLO White” and “Umberall” had a high yield compared to the other varieties and hybrids, accounted for 15 tons/ha and 15.1 tons/ha, respectively. The highest average temperature during seed germination was found in 16 august, which was 30.3°C, whereas the lowest average temperature was 18.6°C in 1st April. The results showed that 4 days were required to reach 10% of seed germination in the period April 16 and May 1, however, 10% of seed germination in July 1 and 16th took 6 days. Furthermore, the least days for 75% of seed, germination was observed in the period of May 1, accounted for 8 days, and the rest of the period was the same.

scholarly journals Analysis of viticulture region climate structure and suitability in New Zealand

OENO One ◽  
2012 ◽  
Vol 46 (3) ◽  
pp. 149 ◽  
Author(s):  
Jon D. Anderson ◽  
Gregory V. Jones ◽  
Andrew Tait ◽  
Andrew Hall ◽  
Michael C.T. Trought
Keyword(s):  
New Zealand ◽  
Growing Season ◽  
Climate Indices ◽  
Growing Degree Days ◽  
Methodological Issues ◽  
Warm Climate ◽  
Degree Days ◽  
Average Temperature ◽  
Climate Suitability ◽  
Two Indices

<p style="text-align: justify;"><strong>Aims</strong>: This research analyzes four climate indices derived from gridded, interpolated data to assess New Zealand’s climate structure and variation among wine regions.</p><p style="text-align: justify;"><strong>Methods and results</strong>: High resolution gridded data based on 1971-2000 climate normals was used to characterize climate indices depicting viticultural suitability in a geographic information system. The statistical properties of each index were assessed over 21 New Zealand viticulture regions. The results show predominately cool to moderately warm climate suitability in New Zealand, comparable to many European and United States regions. While many viticulture regions have one primary class of suitability, variability of climate within regions can be significant, with some regions containing two to four climate classes, making them suitable for a greater range of cultivars.</p><p style="text-align: justify;"><strong>Conclusion</strong>: While the indices depict broad patterns expected over New Zealand, both within and between region variations can be substantial among the indices. However, two indices, Growing Season Average Temperature (GST) and Growing Degree-Days (GDD), are functionally identical, but GST is easier to calculate and overcomes many methodological issues in GDD.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: This research provides the basis for evaluating general suitability for viticulture in New Zealand, assists comparisons between viticulture regions in New Zealand and worldwide, and offers growers measures of assessing appropriate cultivars and sites.</p>

The effect of planting date on the yield and some fibre properties of cotton in the Namoi Valley

1976 ◽  
Vol 16 (79) ◽  
pp. 265 ◽  
Author(s):  
GA Constable ◽  
NV Harris ◽  
RE Paull
Keyword(s):  
Adverse Effect ◽  
Maximum Yield ◽  
Planting Date ◽  
Growing Degree Days ◽  
Degree Days ◽  
Planting Dates ◽  
Fibre Properties ◽  
Commercial Cultivar ◽  
Yield Variation ◽  
Early Maturing

The effect of planting dates between September 30 and November 30 on the yield and some fibre properties of two cotton cultivars has been studied over three seasons. The yield of the commercial cultivar (Deltapine Smoothleaf) fell by an average of 20 kg ha-1 day-1 delay in planting after October 20, earlier planting dates having equal yields, producing a plateau effect. The yield of an early maturing cultivar (Short Sympodial) fell linearly by 11 kg ha-1 day-1 delay in planting. Planting dates after mid-October had an adverse effect on micronaire in the commercial cultivar, but lint length and strength were not affected. Thus maximum yield and micronaire for plantings after mid-October came from the early cultivar. Tolerance to low temperature is an important factor in cultivar earliness, and accounts for the performance of Short Sympodial in these experiments. The number of days from first flower to first frost was as reliable as growing degree days in explaining yield variation within a cultivar

AN EVALUATION OF THE CORN HEAT UNIT SYSTEM FOR THE SHORT-SEASON GROWING REGIONS ACROSS CANADA

1983 ◽  
Vol 63 (1) ◽  
pp. 121-130 ◽  
Author(s):  
D. J. MAJOR ◽  
D. M. BROWN ◽  
A. BOOTSMA ◽  
G. DUPUIS ◽  
N. A. FAIREY ◽  
...  
Keyword(s):  
Temperature Adaptation ◽  
Genotypic Differences ◽  
Growing Degree Days ◽  
Thermal Unit ◽  
Degree Days ◽  
Weather Factors ◽  
Heat Unit ◽  
Corn Hybrids ◽  
Unit System ◽  
Different Climates

A study was conducted at 11 locations across Canada to determine if corn hybrids have different corn heat unit (CHU) requirements in different climates. The study included six hybrids, four each in the three years 1977–1979. Differences in the time between planting and emergence were attributable to slow emergence of two hybrids as well as management and weather factors at different locations. Genotypic differences were expressed mainly in the period between emergence and anthesis. At three locations, 198 CHU more were required than at other locations. In the period from anthesis to 45% ear moisture, two hybrids required more CHU than other hybrids. These extra CHU requirements were not related to hybrid rating, i.e., late-maturing hybrids did not require more CHU to complete the ripening phase. In a comparison of growing degree days (GDDi) with bases ranging from 5 to 15 °C, no one thermal unit had sufficient advantage over the CHU system to warrant its adoption in Canada. Further, calendar days were the best for predicting the duration of the period from planting to emergence. The period from emergence to 10% anthesis was least variable of all the stages and could be predicted accurately by any of the methods.Key words: Zea mays, temperature, adaptation, thermal units

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