scholarly journals Applied use of growing degree days to refine optimum times for nitrogen stress sensing in winter wheat

2020 ◽  
Vol 112 (1) ◽  
pp. 537-549 ◽  
Author(s):  
Jagmandeep S. Dhillon ◽  
Bruno M. Figueiredo ◽  
Elizabeth M. Eickhoff ◽  
William R. Raun
Keyword(s):  
Winter Wheat ◽  
Nitrogen Stress ◽  
Growing Degree Days ◽  
Degree Days ◽  
Stress Sensing

scholarly journals Projecting Future Change in Growing Degree Days for Winter Wheat

Agriculture ◽  
2016 ◽  
Vol 6 (3) ◽  
pp. 47 ◽  
Author(s):  
Natalie Ruiz Castillo ◽  
Carlos Gaitán Ospina
Keyword(s):  
Winter Wheat ◽  
Growing Degree Days ◽  
Degree Days ◽  
Future Change

Availability of late-season heat and water resources for relay and double cropping with winter wheat in prairie Canada

2001 ◽  
Vol 81 (2) ◽  
pp. 273-276 ◽  
Author(s):  
Joanne R. Thiessen Martens ◽  
Martin H. Entz
Keyword(s):  
Water Resources ◽  
Winter Wheat ◽  
Cropping System ◽  
Weather Data ◽  
Growing Degree Days ◽  
Degree Days ◽  
Late Season ◽  
Double Cropping ◽  
No Till

Long-term weather data for 21 sites across Manitoba, Saskatchewan and Alberta were analyzed to evaluate the availability of late-season heat and water resources between time of winter wheat maturity and freeze-up. Thermal time during this period ranged from 159 to 754 growing degree days; precipitation ranged from 42 to 152 mm. Southern Manitoba appears to be best suited to relay and double cropping. Southern Saskatchewan receives significant thermal energy; however, lack of precipitation may limit late season plant growth. Key words: Legumes, no-till, cropping system intensity

DISTRIBUTION AND SEASONAL ABUNDANCE OF SITODIPLOSIS MOSELLANA (DIPTERA: CECIDOMYIIDAE) IN SPRING WHEAT

1999 ◽  
Vol 131 (3) ◽  
pp. 387-397 ◽  
Author(s):  
R.J. Lamb ◽  
I.L. Wise ◽  
O.O. Olfert ◽  
J. Gavloski ◽  
P.S. Barker
Keyword(s):  
Winter Wheat ◽  
Spring Wheat ◽  
Seasonal Abundance ◽  
Wheat Crop ◽  
Growing Degree Days ◽  
Degree Days ◽  
Peak Period ◽  
Sitodiplosis Mosellana ◽  
Wheat Midge ◽  
Heading Stage

AbstractThe wheat midge Sitodiplosis mosellana (Géhin) occurred in all wheat-growing areas of Manitoba during 1993–1997, with 95% of spring wheat fields having some seeds infested by larvae. The level of infestation varied, but each year in excess of 20% of seeds were infested in some fields. Infestation levels in adjacent fields were more similar than in fields separated by a few kilometres. Within fields, the infestation was similar at the edge and near the centre. Wheat midge larvae also overwintered in, and adults emerged from, fields in all wheat-growing areas of Manitoba. Adults emerged from the end of June to the end of July most years, and the peak period for adult flight was mid-July, about 1 month later than in parts of Europe where winter wheat predominates. The timing of the emergence was similar from place to place and year to year. Females constituted 95% of insects caught in a flight trap. The first 10% and 50% of the flight occurred on 9 and 16 July, respectively, and the timing of the flight was not related to growing degree-days. In early August, mature larvae began dropping from wheat heads. The timing of infestation of spring wheat was variable among years because of differences in timing between midge flights and the susceptible heading stage of the crop. Nevertheless, the wheat midge flight usually coincided with the susceptible stage of the spring wheat crop.

Predicting timing of downy brome (Bromus tectorum) seed production using growing degree days

Weed Science ◽  
2004 ◽  
Vol 52 (4) ◽  
pp. 518-524 ◽  
Author(s):  
Daniel A. Ball ◽  
Sandra M. Frost ◽  
Alix I. Gitelman
Keyword(s):  
United States ◽  
Winter Wheat ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Growing Degree Days ◽  
Viable Seed ◽  
Downy Brome ◽  
Degree Days

Downy brome in dryland winter wheat presents a major constraint to the adoption of reduced tillage cropping systems in the Pacific Northwest of the United States. Effective suppression of downy brome during fallow periods depletes seed in the soil and reduces infestations in subsequent winter wheat crops. Delayed tillage operations or delayed herbicide applications in the spring increase the risk for production of viable downy brome seed during fallow periods. In a series of studies, downy brome panicles were sequentially sampled at Pendleton, OR, and Pullman, WA, in 1996 and 1997, and at nine locations around the winter wheat growing region of the western United States in 1999 and 2001. Cumulative growing degree days (GDD) were calculated using local, daily maximum, and minimum air temperature data. A simple GDD model based on the formula GDD = (daily maximum temperature [C] + daily minimum temperature [C])/2, with a base temperature of 0 C and a starting point of January 1, was used to calculate cumulative GDD values for panicle sampling dates. Number of seed germinating per collected panicle was recorded in greenhouse germination tests. Estimations of degree days required for production of viable downy brome seed were made using nonlinear regression of germination on GDD. The GDD value at which viable seed can be found on plants (i.e., when seed germination > 0) was of interest. Estimates of the GDD values at which viable seed could be found in the three studies ranged from 582 GDD at Bozeman, MT, to 1,287 GDD at Stillwater, OK, with a group of GDD values for Pendleton and Pullman around 1,000. Variation in seed-set GDD among locations may be attributed to differing climatic conditions that control vernalization at the various locations or to differences in vernalization requirements among downy brome biotypes (or both).

Evaluation of Finger Millet Varieties under Rainfed Condition of Eastern India

2017 ◽  
Vol 4 (03) ◽  
Author(s):  
M. K. Singh ◽  
VINOD KUMAR ◽  
SHAMBHU PRASAD
Keyword(s):  
Field Experiment ◽  
Finger Millet ◽  
Yield Potential ◽  
Growing Degree Days ◽  
Eastern India ◽  
Degree Days ◽  
Rainfed Condition ◽  
Net Returns ◽  
Humid Environment ◽  
Use Efficiency

A field experiment was carried out during the kharif of 2014 and 2015 to evaluate the yield potential, economics and thermal utilization in eleven finger millet varieties under the rainfed condition of the sub-humid environment of South Bihar of Eastern India. Results revealed that the significantly higher grain yield (20.41 q ha-1), net returns (Rs 25301) and B: C ratio (1.51) was with the finger millet variety ‘GPU 67’ but was being at par to ‘GPU28’and ‘RAU-8’, and significantly superior over remaining varieties. The highest heat units (1535.1oC day), helio-thermal units (7519.7oC day hours), phenothermal index (19.4 oC days day-1) were recorded with variety ‘GPU 67’ followed by ‘RAU 8’ and ‘GPU 28’ and lowest in ‘VL 149’ at 50 % anthesis stage. Similarly, the highest growing degree days (2100 oC day), helio-thermal units (11035.8 oC day hours) were noted with ‘GPU 67’ followed by ‘RAU 8’ and ‘GPU 28’ at maturity. The highest heat use efficiency (0.97 kg ha-1 oC day) and helio-thermal use efficiency (0.19 kg ha-1 oC day hour) were in ‘GPU 67’ followed by ‘VL 315’.

scholarly journals Determining the critical period for weed control in high-yielding cotton using common sunflower as a mimic weed

2019 ◽  
Vol 33 (6) ◽  
pp. 800-807 ◽  
Author(s):  
Graham W. Charles ◽  
Brian M. Sindel ◽  
Annette L. Cowie ◽  
Oliver G. G. Knox
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Yield Loss ◽  
Field Studies ◽  
Growing Degree Days ◽  
Degree Days ◽  
Weed Density ◽  
High Level ◽  
The Cost ◽  
Planting Season

AbstractField studies were conducted over six seasons to determine the critical period for weed control (CPWC) in high-yielding cotton, using common sunflower as a mimic weed. Common sunflower was planted with or after cotton emergence at densities of 1, 2, 5, 10, 20, and 50 plants m−2. Common sunflower was added and removed at approximately 0, 150, 300, 450, 600, 750, and 900 growing degree days (GDD) after planting. Season-long interference resulted in no harvestable cotton at densities of five or more common sunflower plants m−2. High levels of intraspecific and interspecific competition occurred at the highest weed densities, with increases in weed biomass and reductions in crop yield not proportional to the changes in weed density. Using a 5% yield-loss threshold, the CPWC extended from 43 to 615 GDD, and 20 to 1,512 GDD for one and 50 common sunflower plants m−2, respectively. These results highlight the high level of weed control required in high-yielding cotton to ensure crop losses do not exceed the cost of control.

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