Relationship between relative time of emergence of Tartary buckwheat (Fagopyrum tataricum) and yield loss of barley

2002 ◽  
Vol 82 (4) ◽  
pp. 861-863 ◽  
Author(s):  
J. T. O’Donovan ◽  
A. S. McClay
Keyword(s):  
Decision Support ◽  
Hordeum Vulgare ◽  
Regression Model ◽  
Nonlinear Regression ◽  
Yield Loss ◽  
Tartary Buckwheat ◽  
Nonlinear Regression Model ◽  
Fagopyrum Tataricum ◽  
Hordeum Vulgare L ◽  
Relative Time

A nonlinear regression model was used to describe the relationship between Tartary buckwheat [Fagopyrum tataricum (L.) Gaertn.] density and relative time of emergence, and yield of barley (Hordeum vulgare L.). Yield loss increased the earlier the weed emerged relative to the crop. The model is being used in computerized decision support systems for weed management in western Canada. Key words: Fagopyrum tataricum, Hordeum vulgare, nonlinear regression model, relative time of emergence, decision support system

Influence of Tartary Buckwheat (Fagopyrum tataricum) Density on Yield Loss of Barley (Hordeum vulgare) and wheat (Triticum aestivum)

Weed Science ◽  
1985 ◽  
Vol 33 (4) ◽  
pp. 521-523 ◽  
Author(s):  
E. Ann de St. Remy ◽  
John T. O'Donovan ◽  
Alan K. W. Tong ◽  
P. Ashley O'Sullivan ◽  
M. Paul Sharma ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Hordeum Vulgare ◽  
Yield Loss ◽  
Plant Density ◽  
Wheat Yield ◽  
Tartary Buckwheat ◽  
Yield Reduction ◽  
Regression Equations ◽  
Fagopyrum Tataricum ◽  
The Relationship

The relationship between Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn. ♯ FAGTA) plant density (x) and percent yield loss (ŷ) was expressed by the following linear regression equations for barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.), respectively; ŷ = 0.63 + 2.75 √x and ŷ = 5.04 + 3.05 √x. Tartary buckwheat causes serious yield reduction in barley and wheat. A Tartary buckwheat density at 30 plants/m2 at emergence reduced barley yield by 16% and wheat yield by 22%.

scholarly journals Dimension Analysis-Based Model for Prediction of Shale Compressive Strength

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Xiangyu Fan ◽  
Fenglin Xu ◽  
Lin Chen ◽  
Qiao Chen ◽  
Zhiwei Liu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Regression Model ◽  
Nonlinear Regression ◽  
Prediction Error ◽  
Diameter Ratio ◽  
Nonlinear Regression Model ◽  
Average Prediction Error ◽  
Model Average ◽  
Dimension Analysis ◽  
Longmaxi Shale

The compressive strength of shale is a comprehensive index for evaluating the shale strength, which is linked to shale well borehole stability. Based on correlation analysis between factors (confining stress, height/diameter ratio, bedding angle, and porosity) and shale compressive strength (Longmaxi Shale in Sichuan Basin, China), we develop a dimension analysis-based model for prediction of shale compressive strength. A nonlinear-regression model is used for comparison. A multitraining method is used to achieve reliability of model prediction. The results show that, compared to a multi-nonlinear-regression model (average prediction error = 19.5%), the average prediction error of the dimension analysis-based model is 19.2%. More importantly, our dimension analysis-based model needs to determine only one parameter, whereas the multi-nonlinear-regression model needs to determine five. In addition, sensitivity analysis shows that height/diameter ratio has greater sensitivity to compressive strength than other factors.

Dicamba Uptake, Translocation, Metabolism, and Selectivity

Weed Science ◽  
1971 ◽  
Vol 19 (1) ◽  
pp. 113-117 ◽  
Author(s):  
F. Y. Chang ◽  
W. H. Vanden Born
Keyword(s):  
Hordeum Vulgare ◽  
Root Uptake ◽  
Tartary Buckwheat ◽  
Fagopyrum Tataricum ◽  
Sinapis Arvensis ◽  
Triticum Vulgare ◽  
Wild Mustard ◽  
Minor Metabolite ◽  
Anisic Acid ◽  
A Minor

Greenhouse studies indicated that 3,6-dichloro-o-anisic acid (dicamba) or its metabolic derivative was strongly accumulated in meristematic tissues of Tartary buckwheat (Fagopyrum tataricum(L.) Gaertn.) and wild mustard (Sinapis arvensisL.) following both foliar and root uptake. In barley (Hordeum vulgareL.) and wheat (Triticum vulgareL.), it was distributed throughout the plants. Detoxification of dicamba occurred in all four species though not at equal rates, and a common major metabolite was identified chromatographically as 5-hydroxy-3,6-dichloro-o-anisic acid. A minor metabolite, 3,6-dichlorosalicylic acid, was found in barley and wheat but not in Tartary buckwheat or wild mustard. The four species tolerated dicamba treatment in the order of wheat, barley, wild mustard, and Tartary buckwheat. This ranking corresponds with the ability of the plants to detoxify dicamba and is inversely related to the extent of dicamba absorption and translocation in them.

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