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SAIN Invasive Plant Pests Resource Collection for Veronica hederaefolia
Common name: Speedwell
| Title: Modeling weed emergence as a function of meteorological records. |
| Author: Grundy-Andrea-C ; Mead-Andrew. |
| Source: Weed-Science. 48 (5): 594-603. |
| Source Type: Journal |
| Publication Date: 2000 |
| Abstract: Unique long-term historical emergence records were used to assess the association between weed seedling emergence and various elements of meteorological data. These elements included both temperature-based and rainfall-related variables in the 7-d periods before and during which emergence occurred. Five weed species (Stellaria media, Chenopodium album, Capsella bursa-pastoris, Matricaria perforata, and Veronica hederifolia) with contrasting emergence patterns were studied in disturbed soil. Logistic regression analysis was used to identify meteorological variables of interest and allowed their relative importance to be assessed and ranked. Logistic regression was further used to associate probabilities of emergence with observed levels of important individual meteorological elements. This approach enabled prediction of the probability of emergence following given meteorological conditions and hence an assessment of the risk of omitting weed control measures. Predictions were made based on single meteorological variables and compared with observed data. Results indicated that temperature was the dominant factor in predicting emergence. Soil moisture, while also important, was a secondary factor only becoming important once the species-specific temperature requirement had been satisfied. The potential for further development of the model is discussed. |
| Title: Ecological characteristics of Veronica hederifolia in China. |
| Author: Guo-Shuiliang. |
| Source: Yingyong-Shengtai-Xuebao. 9 (2) 133-138. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Ivy-leaved speedwell (Veronica hederifolia), an important weed in crop fields throughout Mediterranean countries, was transferred into China in 1980's. This paper dealt with its individual's physiological and ecological characteristics and its population niche. In well aerated soil, the percentage of its seed germination was higher and 10 apprx 20% of soil water content was favorable to germination. Soil pH showed a little effect on germination, but lower temperature promoted it. Ivy-leaved speedwell had a similar photosynthesis characteristic with V. persica, and its respiratory intensity was lower than that of other weeds in the same genus. Its actual niche breadth in non-crop field habitats in Nanjing suburbs was narrower than that of V. persica and V. didyma. The actual niche overlaps show that V. hederifolia had a similar ecological demand with V. persica and V. didyma. |
| Title: Spatial correlation analysis between weed occurrence and those of the previous year and abiotic soil properties by example of ivy-leaved speedwell (Veronica hederifolia L.) and nitrogen content. |
| Author: Dammer-K-H ; Koerner-S; Wittmann-C. |
| Source: Journal-of-Agronomy-and-Crop-Science. 181 (3) 161-166. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: The spatial dependence of the occurrence of Veronica hederifolia L. on the previous year and on the nitrogen content of the soil (0-30cm) is characterized by cross correlograms. These are drawn by use of the correlation coefficient of Pearson's rho and Kendall's taub. The results from cross correlograms are compared with the correlation coefficients at the same sampling location between the occurrence of the weed for 2 consecutive years running and also between the nitrogen content and the weed occurrence in the same year. With the help of the cross correlograms we found up to which distances the two variables correlate significantly. The correlation coefficient calculated between two variables at the same sampling point are not sufficient to characterize their spatial dependence. Kendall's taub, corrected for ties, as a nonparametric measure of correlation, leads in two cases to more significant dependencies than does Pearson's correlation coefficient. |
| Title: Effect of isoxaben application rate and timing on residual broadleaf weed control in turf. |
| Author: Chandran-Rakesh-S ; Derr-Jeffrey-F; Bingham-S-Wayne. |
| Source: Weed-Technology. 1998; 12 (4) 569-574. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Duration and spectrum of preemergence (PRE) weed control following isoxaben application at 0.56, 0.84, and 1.12 kg ai/ha in spring, fall, or spring plus fall (double) application were evaluated by field experiments. Residual activity of isoxaben was assessed by monitoring weed counts at two locations for 12 mo after treatment (MAT). Buckhorn plantain and dandelion control from spring-applied isoxaben at 1.12 kg/ha was > 90% at 4 MAT in Blacksburg but dropped to < 51% at 12 MAT. Isoxaben at 1.12 kg/ha applied in fall provided gtoreq 90% control of buckhorn plantain for 8-9 MAT, with control ranging from 69 to 91% at approximately 12 MAT. Dandelion control with fall-applied isoxaben at 1.12 kg/ha ranged from 60 to 75%, 8-9 MAT. Fall application of 1.12 kg/ha isoxaben at Virginia Beach controlled henbit and cornspeedwell for 2-3 MAT. Multiple applications of isoxaben improved weed control at Virginia Beach, but results were inconclusive at Blacksburg. In comparison, oxadiazon controlled white sweet clover and dandelion for 1 MAT following spring application in Blacksburg, but < 65% broadleaf control was observed at 4 MAT. Broadleaf weed control following single application of oxadiazon at 3.36 kg/ha was < 60% at 9 MAT. Poor weed control resulted from spring applications of isoxaben and oxadiazon when a 25-cm precipitation occurred within 2 wk after application in one study. |
| Title: Synthesis of N-alkyl-2,3-dimethyl-5-(N'-(5-halo-2-methylphenyl)carbamoyl)-6-pyrazinecarboxamides and their herbicidal activity. |
| Author: Tsuda-Tadataka ; Kobayashi-Kohichi; Ichimoto-Itsuo. |
| Source: Journal-of-Pesticide-Science.22 (3) 218-221. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: NA |
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