Glyphosate influence on sugarbeet production and control of Abutilon theophrasti, Chenopodium album, and Amaranthus species using weed growth stage and growing degree days.

2009 ◽  
Author(s):  
Mark W. Bredehoeft ◽  
Mark W. Bloomquist ◽  
Chris C. Dunsmore ◽  
Cody W. Bakker
Keyword(s):  
Growth Stage ◽  
Chenopodium Album ◽  
Abutilon Theophrasti ◽  
Growing Degree Days ◽  
Degree Days ◽  
Weed Growth ◽  
And Control

scholarly journals Sensitivity of Chenopodium album and Abutilon theophrasti to mesotrione depending on the growth stage

2016 ◽  
Vol 25 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Filip Vranješ ◽  
Nikola Arsenijević ◽  
Dragana Božić
Keyword(s):  
Growth Stage ◽  
Chenopodium Album ◽  
Abutilon Theophrasti

Hophornbeam Copperleaf (Acalypha ostryifolia) Biology and Control

1998 ◽  
Vol 12 (3) ◽  
pp. 515-521 ◽  
Author(s):  
Michael J. Horak ◽  
Zhuping Gao ◽  
Dallas E. Peterson ◽  
Larry D. Maddux
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Dry Matter ◽  
Growing Degree Days ◽  
Dry Matter Accumulation ◽  
Cold Stratification ◽  
Degree Days ◽  
And Control

Little is known about the biology and control of hophornbeam copperleaf, a weed of increasing importance in the Midwest. More than 2 wk of cold stratification and a 0.2% KNO3solution increased germination of hophornbeam copperleaf. Germination at constant 30 C was 47% and alternating 30/20 C was 65%. Scarification did not increase hophornbeam copperleaf germination. Within the first 600 growing degree days after soybean planting, plant height, leaf area, and dry matter accumulation of hophornbeam copperleaf grown in soybean and alone were similar. Subsequently, leaf area and dry matter accumulation of hophornbeam copperleaf grown alone were greater than of those grown in soybean. In contrast, plant height of hophornbeam copperleaf grown in soybean was greater than when grown alone. Hophornbeam copperleaf grown alone produced up to 12 510 seeds/plant, whereas hophornbeam copperleaf grown with soybean produced 980 seeds/plant. Of 13 postemergent herbicides evaluated on hophornbeam copperleaf in soybean, only lactofen, acifluorfen, and fomesafen controlled 80% or more. Lactofen at 210 g ai/ha consistently controlled more than 95% of the hophornbeam copperleaf.

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 Sunflower seed germination and storability response to chemical desiccation

2020 ◽  
Vol 26 (2) ◽  
pp. 53-60
Author(s):  
Petar Čanak ◽  
Milan Jocković ◽  
Bojana Vujošević ◽  
Milosav Babić ◽  
Bojan Mitrović ◽  
...  
Keyword(s):  
Seed Germination ◽  
Significant Loss ◽  
Growing Degree Days ◽  
Degree Days ◽  
Performance Time ◽  
Seed Moisture ◽  
Negative Effect ◽  
High Level ◽  
Harvest Maturity ◽  
And Control

The objective was to assess the effect of chemical desiccation on seed germination and storability in three sunflower female inbred lines and to point at possible indicators for optimal performance time. Desiccation was performed with Diquat (2 l ha-1) applied at 7-day intervals from the end of flowering to harvest maturity. There were 6 treatments and control (untreated). Germination was tested 2 and 21 months after harvest. The highest germination was recorded when the desiccation was performed 35 days after flowering. Results showed that optimal moment for applying chemical desiccation when there is no negative effect on the seed germination is specific for each sunflower genotype. Seeds with a high level of germination (>90%) can be stored for 19 months without significant loss in germination, namely, it was not negatively affected by chemical desiccation. Seed moisture and growing degree-days can be used as reliable indicators for optimal desiccation time.

scholarly journals The role of the growth stage of weeds in their response to reduced herbicide doses

2012 ◽  
Vol 64 (4) ◽  
pp. 259-266 ◽  
Author(s):  
Renata Kieloch ◽  
Krzysztof Domaradzki
Keyword(s):  
Growth Stage ◽  
Chenopodium Album ◽  
Growth Stages ◽  
Weed Species ◽  
Stellaria Media ◽  
State Research Institute ◽  
Plant Cultivation ◽  
Weed Growth ◽  
Herbicide Effects ◽  
Anthemis Arvensis

The influence of weed growth stage on the efficacy of selected herbicides applied at reduced doses was investigated under pot experiments at the Institute of Soil Science and Plant Cultivation - State Research Institute in Wrocław. Three weed species were used as tested plants: <i>Anthemis arvensis</i> L., <i>Chenopodium album</i> L. and <i>Stellaria media</i> L., which were sprayed at different growth stages: 2-4, 6-8, and 10-12 leaves. The experiment included the following herbicides: tribenuron-methyl, iodosulfuron methyl sodium + amidosulfuron, and metribuzin + amidosulfuron, used at full doses and reduced by 25 and 50%. Three weeks after treatment, fresh weight of weeds was determined. Weed control was significantly related to weed species, growth stage, type of herbicide and its dose. Among the tested weed species, <i>S. media</i> showed the weakest reaction to the herbicides used and it was only slightly affected by herbicide rate and growth stage. Later herbicide treatments, when the weeds reached the stage of 6-8 and 10-12 leaves, resulted in diversification at the level of herbicide effects and doses.

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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