Floral ontogeny of Swainsona formosa (Fabaceae: Faboideae: Galegeae)

2007 ◽  
Vol 55 (6) ◽  
pp. 643 ◽  
Author(s):  
T. Tapingkae ◽  
A. Taji ◽  
P. Kristiansen
Keyword(s):  
Floral Development ◽  
Floral Organ ◽  
Growth Stages ◽  
Growing Degree Days ◽  
Cut Flowers ◽  
Degree Days ◽  
Accurate Identification ◽  
Floral Ontogeny ◽  
Central Stem ◽  
Axillary Branches

Swainsona formosa (G.Don) J.Thompson (Sturt’s desert pea) is used in commercial floriculture for cut flowers and ornamental pot plants; however, accurate identification of the growth stages is critically important in making management decisions in floricultural crops. This plant was investigated by stereomicroscopy and scanning electron microscopy (SEM) to identify flowering time and stages of floral development. This is the first work to describe the complete floral ontogeny in a member of tribe Galegeae. Conversion from vegetative to reproductive stages began within 40–46 days after seed germination for axillary branches and within 46–52 days for central stems. Plants required 807.5 days °C growing degree-days for axillary branches and 921.5 days °C for central stems to reach 50% flowering. The central stem grew more nodes (11.1 ± 0.97 nodes) before the initiation of the first flower than did the axillary branches (7.2 ± 0.93 nodes). The order of floral organ initiation within each whorl is unidirectional, except for the petal whorl, which is simultaneous; the flower is organised into five whorls and shows a pentamerous arrangement of sepals and petals, 10 stamens in two whorls and a central carpel.

scholarly journals GROWTH STUDIES WITH SNAP BEANS TO PREDICT HARVEST

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1140e-1140
Author(s):  
Entin Daningsih ◽  
D. L. Coffey ◽  
J. Logan ◽  
C. A. Mullins
Keyword(s):  
Developmental Stages ◽  
Radiant Energy ◽  
Planting Date ◽  
Growth Stages ◽  
Growing Degree Days ◽  
Phaseolus Vulgaris L ◽  
Degree Days ◽  
Snap Beans ◽  
Growing Degree Hours ◽  
Harvest Maturity

Studies were initiated in 1989 to characterize phonological events with corresponding growth and development phenomena of `Eagle' and `Provider' snap beans (Phaseolus vulgaris L.) Ten plantings at approximately 15 day intervals were made at Knoxville, TN from April 17 through July 27. Days to reach growth stages V0 thru R7 were recorded for each cultivar for each planting date. Air temperature, total radiant energy, wind speed and relative humidity were recorded hourly throughout the 171 day test period. Growing degree days (GDD) computed by 8 methods and growing degree hours (GDH) computed by 2 methods were regressed against plant developmental stages. GDD and GDH, along with pod size and pod fiber content, will be discussed as possible indices for predicting harvest maturity. With the methods used to calculate heat summation in this study, GDD and GDH from planting to pod maturity ranged from approximately 550 to 975 and 9,700 to 20,000, respectively.

scholarly journals Production and Commercialization of Helianthus annuus L. for Cut Flowers in Texcoco, Mexico

2021 ◽  
Vol 14 (05) ◽  
Author(s):  
V. García-Reyes ◽  
J. Silvano-Sánchez ◽  
J. Zavala-Ruiz ◽  
L. Meraz-Huescas ◽  
Obdulia Baltazar-Bernal
Keyword(s):  
Helianthus Annuus ◽  
Cost Benefit ◽  
Sowing Date ◽  
Added Value ◽  
Growing Degree Days ◽  
Cut Flowers ◽  
Degree Days ◽  
Helianthus Annuus L ◽  
Flower Diameter ◽  
Cutting Point

Objective: To evaluate the process of sunflower production (Helianthus annuus L.) for fresh cutting flowers, considering two sowing dates, growing degree-days, and commercialization. Design/Methodology/Approach: A completely randomized experimental design with subsampling was used, with five repetitions per treatment (sowing date), in order to analyze the variables: number of leaves, height, and flower diameter. Vincent Choice Dark Eye Ball™ sunflowers were sown in black plastic boxes with 8 cm of soil on January 31 and February 11, 2020, at 153 plants per m-2 in a greenhouse. Later, the seedlings were grown in the open field until harvesting, after which they were given added value and then locally traded. In addition, the growing degree-days (GDD) were calculated. Results: The sunflowers registered a height of 55 cm, 13 leaves per stalk, and a flower diameter of 6.88 cm. Late sowing favored the height and diameter of the flower. The sunflower hybrid required more GDD to reach commercial flower maturity in the first sowing date. The cost-benefit ratio was 1.38. Study Limitations/Implications: Seeds were sown on only two dates. Findings/Conclusions: The production process involved planning, management, and commercialization. The sunflower hybrid required on average 499 GDD to reach the cutting point. The added value increased the price fivefold.

scholarly journals Effect of soybean growth stage on sensitivity to sublethal rates of dicamba and 2,4-D

2019 ◽  
Vol 33 (04) ◽  
pp. 555-561 ◽  
Author(s):  
Alanna B. Scholtes ◽  
Benjamin P. Sperry ◽  
Daniel B. Reynolds ◽  
J. Trenton Irby ◽  
Thomas W. Eubank ◽  
...  
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Yield Loss ◽  
Specific Growth ◽  
Growth Stages ◽  
Growing Degree Days ◽  
Multiple Exposure ◽  
Degree Days ◽  
Target Movement ◽  
Visible Injury

AbstractField experiments were conducted in 2012 and 2013 across four locations for a total of 6 site-years in the midsouthern United States to determine the effect of growth stage at exposure on soybean sensitivity to sublethal rates of dicamba (8.8 g ae ha−1) and 2,4-D (140 g ae ha−1). Regression analysis revealed that soybean was most susceptible to injury from 2,4-D when exposed between 413 and 1,391 accumulated growing degree days (GDD) from planting, approximately between V1 and R2 growth stages. In terms of terminal plant height, soybean was most susceptible to 2,4-D between 448 and 1,719 GDD, or from V1 to R4. However, maximum susceptibility to 2,4-D was only between 624 and 1,001 GDD or from V3 to V5 for yield loss. As expected, soybean was sensitive to dicamba for longer spans of time, ranging from 0 to 1,162 GDD for visible injury or from emergence to R2. Likewise, soybean height was most affected when dicamba exposure occurred between 847 and 1,276 GDD or from V4 to R2. Regarding grain yield, soybean was most susceptible to dicamba between 820 and 1,339 GDD or from V4 to R2. Consequently, these data indicate that soybean response to 2,4-D and dicamba can be variable within vegetative or reproductive growth stages; therefore, specific growth stage at the time of exposure should be considered when evaluating injury from off-target movement. In addition, application of dicamba near susceptible soybean within the V4 to R2 growth stages should be avoided because this is the time of maximum susceptibility. Research regarding soybean sensitivity to 2,4-D and dicamba should focus on multiple exposure times and also avoid generalizing growth stages to vegetative or reproductive.

scholarly journals A CASE STUDY OF MONITORING MAIZE DYNAMICS IN SERBIA BY UTILIZING SENTINEL-1 DATA AND GROWING DEGREE DAYS

2020 ◽  
Vol V-3-2020 ◽  
pp. 117-124
Author(s):  
M. Pandžić ◽  
N. Ljubičić ◽  
G. Mimić ◽  
J. Pandžić ◽  
B. Pejak ◽  
...  
Keyword(s):  
Climatic Conditions ◽  
Growth Stages ◽  
Growth Monitoring ◽  
Growing Degree Days ◽  
Degree Days ◽  
Radar Backscatter ◽  
Radar Images ◽  
Reliable Source ◽  
Final Yield

Abstract. Due to great significance of maize for Serbian agricultural production, maize growth monitoring during the season is highly important. Some of the growth stages have particular influence on the final yield and without optimal conditions at that point, yield losses may be substantial. Hence, it is crucial to be familiar with transition periods between the stages. Sentinel-1 Synthetic Aperture Radar (SAR) data is a reliable source of information for monitoring various crops in all climatic conditions. Dense time series of radar images offer a unique insight into vegetation dynamics during the season. By combining these with the Growing Degree Days (GDD) method that exploits temperature information in order to position different growth stages in time, more precise estimates of crucial periods in maize development can be made. An experiment was conducted for several maize fields in Serbia for 2017 and 2018 season. GDD estimates were constructed based on literature search and temperature information acquired from the Copernicus Climate Change Service. Despite seasonal weather differences, similar trends in radar backscatter were noticeable and existence of certain growth stages (such as emergence, tasselling, silking and physiological maturity) could be estimated. However, these estimates came up with an uncertainty caused most likely by rain and uneven development of maize that influence radar backscatter. The results were compared with estimates made by an agronomy expert that were not based on field inspection but solely on professional experience due to post-seasonal experiment design. The procedure proved to be practical and applicable all over the world.

Preemergence herbicide delays the critical time of weed removal in popcorn

2019 ◽  
Vol 33 (6) ◽  
pp. 785-793 ◽  
Author(s):  
Ethann R. Barnes ◽  
Stevan Z. Knezevic ◽  
Nevin C. Lawrence ◽  
Suat Irmak ◽  
Oscar Rodriguez ◽  
...  
Keyword(s):  
Growth Stage ◽  
Yield Loss ◽  
Critical Time ◽  
Yield Reduction ◽  
Growth Stages ◽  
Growing Degree Days ◽  
Degree Days ◽  
South Central ◽  
Main Plot ◽  
Weed Removal

AbstractUnderstanding the critical time of weed removal (CTWR) is necessary for designing effective weed management programs in popcorn production that do not result in yield reduction. The objective of this study was to determine the CTWR in popcorn with and without a premix of atrazine and S-metolachlor applied PRE. Field experiments were conducted at the University of Nebraska–Lincoln, South Central Agricultural Laboratory near Clay Center, NE in 2017 and 2018. The experiment was laid out in a split-plot design with PRE herbicide as the main plot and weed removal timing as the subplot. Main plots included no herbicide or atrazine/S-metolachlor applied PRE. Subplot treatments included a weed-free control, a non-treated control, and weed removal timing at V3, V6, V9, V15, and R1 popcorn growth stages and then kept weed free throughout the season. A four-parameter log-logistic function was fitted to percentage popcorn yield loss and growing degree days separately to each main plot. The number of growing degree days, when 5% yield loss was achieved, was extracted from the model and compared between main plots. The CTWR was from the V4 to V5 popcorn growth stage in absence of PRE herbicide. With atrazine/S-metolachlor applied PRE, the CTWR was delayed until V10 to V15. It is concluded that, to avoid yield loss, weeds must be controlled before the V4 popcorn growth stage when no PRE herbicide is applied, and PRE herbicide, such as atrazine/S-metolachlor in this study, can delay the CTWR until the V10 growth stage.

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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