Assessment of Pseudomonas syringae pv. tagetis as a biocontrol agent for Canada thistle
Autor: | John W. Gronwald, Kathryn L. Plaisance, Donald L. Wyse, Donald A. Ide |
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Rok vydání: | 2002 |
Předmět: | |
Zdroj: | Weed Science. 50:397-404 |
ISSN: | 1550-2759 0043-1745 |
DOI: | 10.1614/0043-1745(2002)050[0397:aopspt]2.0.co;2 |
Popis: | Growth chamber and field experiments were conducted to assess the potential of Pseudomonas syringae pv. tagetis (Pst) as a biocontrol agent for Canada thistle. Silwet L-77, an organosilicone surfactant, was required to facilitate Pst penetration into Canada thistle leaves. Growth chamber experiments indicated that maximum Pst populations inside leaves were obtained with a Silwet L-77 concentration of 0.3% (v/v) or greater. High Pst populations (109 colony-forming units [cfu] per gram fresh weight) were found in leaves 48 h after treatment with 108 or 109 cfu ml−1 Pst plus Silwet L-77 (0.3%, v/v). In growth chamber experiments, foliar application of Pst (109 cfu ml−1) plus Silwet L-77 (0.3%, v/v) on 4- to 5-wk-old Canada thistle reduced shoot dry weight by 52% (measured 14 d after treatment) and chlorophyll content of emerging leaves by 92% (measured 10 d after treatment). In field trials conducted in 1999 and 2000, Pst (109 cfu ml−1) plus Silwet L-77 (0.3%, v/v) were applied at 700 L ha−1, and th... |
Databáze: | OpenAIRE |
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