Canopy | Percent reduction | Canopy vigor^{y} | ||||
---|---|---|---|---|---|---|

Treatment method | Herbicide | Tree size | 2002 | 2003 | 2002 | 2003 |

Stem injection | Glyphosate | — | 82.3 ab | 91.7 a | 2.3 b | 1.5 b |

Imazapyr | — | 99.9 ab | 100.0 a | 0.1 b | 0.0 b | |

Triclopyr | — | 66.7 b | 31.4 b | 6.2 a | 6.7 a | |

Basal bark | Imazapyr | <4 cm dia | 100.0 a | 100.0 a | 0.0 b | 0.0 b |

>4 cm dia | 99.8 ab | 100.0 a | 0.1 b | 0.0 b | ||

Triclopyr | <4 cm dia | 90.0 ab | 86.7 a | 1.3 b | 1.7 b | |

>4 cm dia | 100.0 a | 100.0 a | 0.0 b | 0.0 b | ||

Uncut control | — | 12.5 c | 27.1 b | 8.8 a | 7.6 a |

↵

^{z}All canopy percent reduction and vigor measurements made in August of 2002 and 2003. Within each treatment group, values followed by different letters are different at a = 5% (analysis of variance, Student-Newman-Keuls test).↵

^{y}Vigor determined by visual evaluation on scale of 0 = dead and 10 = healthy.