scholarly journals Evaluating the Spectral Response and Yield of Soybean Following Exposure to Sublethal Rates of 2,4-D and Dicamba at Vegetative and Reproductive Growth Stages

2021 ◽  
Vol 13 (18) ◽  
pp. 3682
Author(s):  
Eric Oseland ◽  
Kent Shannon ◽  
Jianfeng Zhou ◽  
Felix Fritschi ◽  
Mandy D. Bish ◽  
...  
Keyword(s):  
Field Experiments ◽  
Yield Loss ◽  
Spectral Response ◽  
The United States ◽  
Growth Stages ◽  
Synthetic Auxin ◽  
Stage Separation ◽  
Loss Estimations ◽  
Vegetative Indices ◽  
Vegetative And Reproductive Growth

The commercialization of synthetic auxin-resistant crops and the commensurate increase in post-emergent auxin-mimic herbicide applications has resulted in millions of hectares of injury to sensitive soybeans in the United States since 2016. Visual yield loss estimations following auxin injury can be difficult. The goal of this research was to determine if spectral variations following auxin injury to soybean allow for more precise yield loss estimations. Identical field experiments were performed in 2018, 2019, and 2020 in Columbia, Missouri to compare the ability of established vegetative indices to differentiate between exposure levels of 2,4-D and dicamba in soybean and predict yield loss. Soybeans were planted at three timings for growth stage separation and were exposed to sublethal rates of 2,4-D and dicamba at the R2, R1, and V3 growth stages. A UAV-mounted multispectral sensor was flown over the trial 14 days after the herbicide treatments. The results of this research found that vegetative indices incorporating the red-edge wavelength were more consistent in estimating yield loss than indices comprised of only visible or NIR wavelengths. Yield loss estimations became difficult when soybean injury occurred during later reproductive stages when soybean biomass was increased. This research also determined that when injury occurs to soybean in vegetative growth stages late in the growing season there is a greater likelihood for yield loss to occur due to decreased time for recovery. The results of this research could provide direction for more objective and accurate evaluations of yield loss following synthetic auxin injury than what is currently available.

The critical weed-free period in glyphosate-resistant soybean in Ontario is similar to previous estimates using glyphosate-susceptible soybean

2019 ◽  
Vol 99 (4) ◽  
pp. 437-443
Author(s):  
Nader Soltani ◽  
Robert E. Nurse ◽  
Amit J. Jhala ◽  
Peter H. Sikkema
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Yield Loss ◽  
Growth Stages ◽  
Weed Species ◽  
Weed Biomass ◽  
Weed Density ◽  
Weed Interference ◽  
Beginning Of Flowering ◽  
Minimal Reduction

A study consisting of 13 field experiments was conducted during 2014–2016 in southwestern Ontario and southcentral Nebraska (Clay Center) to determine the effect of late-emerging weeds on the yield of glyphosate-resistant soybean. Soybean was maintained weed-free with glyphosate (900 g ae ha−1) up to the VC (cotyledon), V1 (first trifoliate), V2 (second trifoliate), V3 (third trifoliate), V4 (fourth trifoliate), and R1 (beginning of flowering) growth stages, after which weeds were allowed to naturally infest the soybean plots. The total weed density was reduced to 24%, 63%, 67%, 72%, 76%, and 92% in Environment 1 (Exeter, Harrow, and Ridgetown) when soybean was maintained weed-free up to the VC, V1, V2, V3, V4, and R1 soybean growth stages, respectively. The total weed biomass was reduced by 33%, 82%, 95%, 97%, 97%, and 100% in Environment 1 (Exeter, Harrow, and Ridgetown) and 28%, 100%, 100%, 100%, 100%, and 100% in Environment 2 (Clay Center) when soybean was maintained weed-free up to the VC, V1, V2, V3, V4, and R1 stages, respectively. The critical weed-free periods for a 2.5%, 5%, and 10% yield loss in soybean were the V1–V2, VC–V1, and VC–V1 soybean stages in Environment 1 (Exeter, Harrow, and Ridgetown) and V2–V3, V2–V3, and V1–V2 soybean stages in Environment 2 (Clay Center), respectively. For the weed species evaluated, there was a minimal reduction in weed biomass (5% or less) when soybean was maintained weed-free beyond the V3 soybean growth stage. These results shows that soybean must be maintained weed-free up to the V3 growth stage to minimize yield loss due to weed interference.

Field Pea and Lentil Tolerance to Interrow Cultivation

2017 ◽  
Vol 32 (2) ◽  
pp. 205-210 ◽  
Author(s):  
Katherine A. Stanley ◽  
Steven J. Shirtliffe ◽  
Dilshan Benaragama ◽  
Lena D. Syrovy ◽  
Hema S. N. Duddu
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Yield Loss ◽  
Growing Season ◽  
Field Pea ◽  
Crop Damage ◽  
Growth Stages ◽  
Row Crops ◽  
Narrow Row ◽  
Mechanical Weed Control

AbstractInterrow cultivation is a selective, in-crop mechanical weed control tool that has the potential to control weeds later in the growing season with less crop damage compared with other in-crop mechanical weed control tools. To our knowledge, no previous research has been conducted on the tolerance of narrow-row crops to interrow cultivation. The objective of this experiment was to determine the tolerance of field pea and lentil to interrow cultivation. Replicated field experiments were conducted in Saskatchewan, Canada, in 2014 and 2015. Weekly cultivation treatments began at the 4-node stage of each crop, continuing for 6 wk. Field pea and lentil yield linearly declined with later crop stages of cultivation. Cultivating multiple times throughout the growing season reduced yield by 15% to 30% in both crops. Minimal yield loss occurred when interrow cultivation was conducted once at early growth stages of field pea and lentil; however, yield loss increased with delayed and more frequent cultivation events.

Cotton Growth and Yield Response to Simulated 2,4-D and Dicamba Drift

2009 ◽  
Vol 23 (4) ◽  
pp. 503-506 ◽  
Author(s):  
John D. Everitt ◽  
J. Wayne Keeling
Keyword(s):  
Good Predictor ◽  
Field Experiments ◽  
Yield Loss ◽  
Lint Yield ◽  
Growth And Yield ◽  
Yield Response ◽  
Growth Stages ◽  
Cotton Lint ◽  
Late Season ◽  
Crop Injury

Field experiments were conducted in Hale Co., TX, in 2005 and 2006 to determine the effects of 2,4-D amine and dicamba applied at varying rates and growth stages on cotton growth and yield, and to correlate cotton injury levels and lint yield reductions. Dicamba or 2,4-D amine was applied at four growth stages including cotyledon to two-leaf, four- to five-leaf, pinhead square, and early bloom. Dicamba and 2,4-D amine were applied at 1/2, 1/20, 1/200, and 1/2000 of the recommended use rate. Crop injury was recorded at 14 days after treatments and late-season, and cotton lint yields were determined. Across all growth stages, 2,4-D caused more crop injury and yield loss than dicamba. Cotton lint was reduced more by later applications (especially pinhead square) and injury underestimated yield loss with 2,4-D. Visual estimates of injury overestimated yield loss when 2,4-D or dicamba was applied early (cotyledon to two leaf) and was not a good predictor of yield loss.

Tolerance and Selectivity of Cereal Species and Cultivars to Postemergence Weed Harrowing

Weed Science ◽  
2009 ◽  
Vol 57 (3) ◽  
pp. 338-345 ◽  
Author(s):  
Jesper Rasmussen ◽  
Helle H. Nielsen ◽  
Hanne Gundersen
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Field Experiments ◽  
Yield Loss ◽  
Soil Cover ◽  
Crop Damage ◽  
Growth Stages ◽  
Crop Tolerance ◽  
Barley Cultivars ◽  
Cereal Species

POST weed harrowing and other cultivation methods to control weeds in early crop growth stages may result in crop damage due to low selectivity between crop and weeds. Crop tolerance to cultivation plays an important role but it has not been clearly defined and analyzed. We introduce a procedure for analyzing crop tolerance on the basis of digital image analysis. Crop tolerance is defined as the ability of the crop to avoid yield loss from cultivation in the absence of weeds, and it has two components: resistance and recovery. Resistance is the ability of the crop to resist soil covering and recovery is the ability to recover from it. Soil covering is the percentage of the crop that has been buried because of cultivation. We analyzed data from six field experiments, four experiments with species of small grains, barley, oat, wheat, and triticale, and two experiments with barley cultivars with different abilities to suppress weeds. The order of species' tolerance to weed harrowing was triticale > wheat > barley > oat and the differences were mainly caused by different abilities to recover from soil covering. At 25% soil covering, grain yield loss in triticale was 0.5%, in wheat 2.5%, in barley 3.7%, and in oat 6.5%. Tolerance, resistance, and recovery, however, were influenced by year, especially for oat and barley. There was no evidence of differences between barley cultivars in terms of tolerance indicating that differences among species are more important than differences among cultivars. Selectivity analysis made it possible to calculate the crop yield loss due to crop damage associated with a certain percentage of weed control. In triticale, 80% weed control was associated with 22% crop soil cover on average, which reduced grain yield 0.4% on average in the absence of weeds. Corresponding values for wheat, barley, and oat were 23, 21, and 20% crop soil cover and 2.3, 3.6, and 5.1% grain yield loss.

Relationship between scald (Rhynchosporium secalis) and losses in grain yield of barley in Western Australia

1985 ◽  
Vol 36 (5) ◽  
pp. 655 ◽  
Author(s):  
TN Khan ◽  
MF D'Antuono
Keyword(s):  
Grain Yield ◽  
Critical Point ◽  
Western Australia ◽  
Field Experiments ◽  
Yield Loss ◽  
Growth Stages ◽  
Point Model ◽  
Percentage Yield ◽  
The Mean ◽  
Ripe Stage

The three commonly used techniques, viz. critical point model, area under the curve and multiple linear regression, were applied to study the relationship between scald infection and grain yield in field experiments conducted during 1979-1983 in Western Australia. In the preliminary analysis leaf three from the top and the mean of the top three leaves were found to be best correlated with yield. The three models did not dilfer greatly, presumably owing to the high correlations between scald at the milky ripe stage and at the earlier growth stages. The critical point model was chosen because of its simplicity. Percentage yield loss in combined data from all experiments showed a significant correlation (P < 0.001) with scald at the milky ripe stage and defined percentage yield loss in cultivars Clipper and Stirling to be about one-third of the mean scald damage on leaves 1 (flag), 2 and 3 at g.s. 75. Due to the range of trials in this analysis, it was suggested that this relationship may be applied to estimate yield loss from survey data in other parts of southern Australia, where scald is endemic.

scholarly journals Warm and Wet Autumns Favour Yield Losses of Oilseed Rape Caused by Phoma Stem Canker

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1171
Author(s):  
Andrzej Brachaczek ◽  
Joanna Kaczmarek ◽  
Malgorzata Jedryczka
Keyword(s):  
Oilseed Rape ◽  
Seed Yield ◽  
Field Experiments ◽  
Yield Loss ◽  
Stem Canker ◽  
Fungal Species ◽  
Growth Stages ◽  
Brassica Napus L ◽  
Phoma Stem Canker ◽  
Plant Growth Stages

Winter oilseed rape (Brassica napus L.) is the main source of domestic oil in central and northern Europe, bringing profits to farmers, but the plants are often damaged by stem canker, caused by two fungal species belonging to the genus Leptosphaeria. Due to environmental concerns, the benefits of fungicide applications must outweigh disadvantages. The aim of this work was to determine the effect of stem canker on seed yield and its quality and find out the best timing of fungicide application. The multi-year field experiments were done at two sites in south-west Poland, where the disease is regarded as a serious problem. The fungicide treatments with the azole-containing preparation followed the same scheme each year; a single application was made at one-week intervals, starting in late September through mid-November for a total of eight treatments. Seed yield, oil and protein content, mass of thousand seeds as well as indole-and alkenyl-glucosinolate contents in seeds were statistically unrelated with the incidence and severity of phoma leaf spotting and stem canker symptoms. The significant decrease of the seed yield was observed in three (site × year combinations) of eight, in which phoma leaf spotting and stem canker were severe. Yield loss was noted only in years with warm and wet autumns, when cumulative mean temperatures between BBCH14 and BBCH19 plant growth stages exceeded 60 °C and precipitation in this period exceeded 110 mm of rain. Under these conditions, fungicide treatments were highly effective when they were done between BBCH15–BBC16 growth stages (5–6 true leaves).

scholarly journals Yield Loss and Economic Threshold Level of Soybean due to Leaf Roller (Apoderus cyaneus Hope) in Nepal

1970 ◽  
Vol 6 ◽  
pp. 73-77
Author(s):  
Bishnu K Gyawali
Keyword(s):  
Population Density ◽  
Field Experiments ◽  
Yield Loss ◽  
Threshold Level ◽  
Growth Stages ◽  
Yield Losses ◽  
Adult Beetle ◽  
Economic Threshold ◽  
Leaf Roller ◽  
Research Journal

Yield loss in soybean due to leaf roller (Apoderus cyaneus Hope) was studied at Khumaltarduring 1985 and 1986 seasons. Field experiments were conducted during vegetative as well asreproductive stages of soybean. Rolled leaves of soybean with eggs, grubs and pupae werecollected from the field and reared in the laboratory for adults. Adults were introduced intonylon cages installed at the central rows of each plot just after germination of soybean. Insectswere maintained at population density of 25, 50 and 100 per m2density, the potential grain yield loss of cultivar, Ransom soybean in its vegetative andreproductive stages were 103 and 48 mg per day respectively from each adult of A. cyaneus.Percentages of yield losses were 36.2, 45.2, and 58.0 during vegetative and 37.5, 48.5 and 66.0during reproductive stages from the insect population of 25, 50 and 100, respectively which, wasnot in accordance with the level of two and four fold increased population density of insect.Yield reduction was higher (260 and 108 mg per day) from each adult beetle at lower populationlevel (25) in both vegetative and reproductive stages of soybean.Key words: Economic threshold level; leaf roller; physiological growth stages; yield lossDOI: 10.3126/narj.v6i0.3367Nepal Agriculture Research Journal Vol.6 2005 pp.73-77

EVALUATION OF VELVETLEAF INTERFERENCE WITH MAIZE HYBRIDS AS INFLUENCED BY RELATIVE TIME OF EMERGENCE

2011 ◽  
Vol 48 (1) ◽  
pp. 127-137 ◽  
Author(s):  
ILIAS S. TRAVLOS ◽  
PANAGIOTIS J. KANATAS ◽  
GARIFALIA ECONOMOU ◽  
VASILIS E. KOTOULAS ◽  
DIMOSTHENIS CHACHALIS ◽  
...  
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Yield Loss ◽  
Integrated Weed Management ◽  
Growth Stages ◽  
Arid Environments ◽  
Initial Growth ◽  
Maize Hybrids ◽  
Canopy Area ◽  
Semi Arid

SUMMARYThe presence of velvetleaf (Abutilon theophrasti) in crops is increasing in arid and semi-arid environments. Field experiments were conducted in Greece in 2009 and 2010 to determine the influence of velvetleaf emergence time and maize (Zea mays) hybrids with different growth rates on maize yield and velvetleaf growth and fecundity. Velvetleaf was uniformly seeded in order to emerge at the 1, 3, 5 and 7-leaf stage of maize (V1, V3, V5 and V7 growth stages, respectively). Velvetleaf biomass, canopy area and seed production were significantly affected by the date of velvetleaf emergence. Velvetleaf plants emerging just after maize (V1) produced 7–17 times lower seed number, compared with the V5 growth stage. Maximum maize grain yield loss ranged from 26 to 37% for early emerging velvetleaf, and less than 6% yield loss occurred from velvetleaf seedlings emerging at V7 growth stage. Maize hybrids with high initial growth rate seem to be more competitive than the other hybrids. The results of this study are essential in the development of an integrated weed management strategy for maize in semi-arid environments, since they highlight the importance of the careful selection of a competitive maize hybrid and avoidance of early velvetleaf emergence.

A Meta-Analysis on the Effects of 2,4-D and Dicamba Drift on Soybean and Cotton

Weed Science ◽  
2014 ◽  
Vol 62 (1) ◽  
pp. 193-206 ◽  
Author(s):  
J. Franklin Egan ◽  
Kathryn M. Barlow ◽  
David A. Mortensen
Keyword(s):  
Crop Yield ◽  
Dose Response ◽  
Yield Loss ◽  
Meta Analysis ◽  
Growth Stages ◽  
Response Curves ◽  
Synthetic Auxin ◽  
Final Yield ◽  
Dose Response Curves ◽  
Herbicide Drift

Commercial introduction of cultivars of soybean and cotton genetically modified with resistance to the synthetic auxin herbicides dicamba and 2,4-D will allow these compounds to be used with greater flexibility but may expose susceptible soybean and cotton cultivars to nontarget herbicide drift. From past experience, it is well known that soybean and cotton are both highly sensitive to low-dose exposures of dicamba and 2,4-D. In this study, a meta-analysis approach was used to synthesize data from over seven decades of simulated drift experiments in which investigators treated soybean and cotton with low doses of dicamba and 2,4-D and measured the resulting yields. These data were used to produce global dose–response curves for each crop and herbicide, with crop yield plotted against herbicide dose. The meta-analysis showed that soybean is more susceptible to dicamba in the flowering stage and relatively tolerant to 2,4-D at all growth stages. Conversely, cotton is tolerant to dicamba but extremely sensitive to 2,4-D, especially in the vegetative and preflowering squaring stages. Both crops are highly variable in their responses to synthetic auxin herbicide exposure, with soil moisture and air temperature at the time of exposure identified as key factors. Visual injury symptoms, especially during vegetative stages, are not predictive of final yield loss. Global dose–response curves generated by this meta-analysis can inform guidelines for herbicide applications and provide producers and agricultural professionals with a benchmark of the mean and range of crop yield loss that can be expected from drift or other nontarget exposures to 2,4-D or dicamba.

Refining crop and livestock management for dual-purpose spring canola (Brassica napus)

2012 ◽  
Vol 63 (5) ◽  
pp. 429 ◽  
Author(s):  
J. A. Kirkegaard ◽  
S. J. Sprague ◽  
P. J. Hamblin ◽  
J. M. Graham ◽  
J. M. Lilley
Keyword(s):  
Brassica Napus ◽  
Field Experiments ◽  
Yield Loss ◽  
Herbicide Tolerance ◽  
Growth Stages ◽  
Dual Purpose ◽  
Residual Biomass ◽  
Mixed Farming ◽  
Spring Canola ◽  
Yield Penalty

Dual-purpose canola (Brassica napus) describes the use of a canola crop for grazed winter forage before seed production, a practice that has only recently been developed in southern Australia. Long-season winter canola has been grazed without yield penalty in higher rainfall zones of Australia (>650 mm) and the USA, but the potential areas are small. The feasibility to graze spring canola varieties across wider areas of the medium-rainfall (450–650 mm), mixed-farming zone in Australia is therefore of interest. We conducted a series of six field experiments involving a range of canola cultivars and grazing management and agronomy systems from 2007 to 2009 at Young in southern New South Wales, Australia, to determine the feasibility of and refine the principles for grazing dual-purpose spring canola without significant yield penalty. Mid-season, Australian spring canola cultivars including conventional and hybrid varieties representing a range of herbicide tolerance (triazine-tolerant, Clearfield®, and Roundup Ready®) were sown from 16 April to 12 May and grazed with sheep at a range of growth stages from early vegetative (June) to mid-flowering (September). In general, early-sown crops (sown mid-April) provided significant grazing (~800 dry sheep equivalent grazing days/ha) in winter before bud elongation, and recovered with no impact on grain yield or oil content. As previously reported, yield was significantly reduced (by up to 1 t/ha) when grazing occurred after buds had elongated (late July), due to the delayed flowering associated with bud removal by sheep and insufficient time for biomass and yield recovery. However, yield was also reduced in crops grazed before bud elongation if insufficient residual biomass remained (<1.0 t/ha for late July lock-up) to facilitate crop recovery even when there was little delay in crop development. We suggest that refinements to the existing ‘phenology-based’ grazing recommendations would assist to avoid yield loss in grazed spring varieties, and propose three grazing stages (safe, sensitive, and unsafe) that integrate the impacts of time, crop growth stage, residual biomass, and seasonal conditions to avoid yield loss under different circumstances. Such refinements to reduce the likelihood of grazing-induced yield loss would provide more confidence for mixed farmers to maximise the benefits from dual-purpose canola in different environments. Based on the outcomes of these experiments, dual-purpose spring canola is likely to have significant potential for wider application in other mixed farming zones, with similar region-specific refinements based on the principles reported here.

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