Tree wound responses to trunk injection for 14 green ash trees in varying stages of health, as reflected by canopy thinning and dieback ratings in the two years following trunk injections (bold text). Cambial injury, wound closure, and ring growth data are means ± sD for four or five injection sites per tree. Trees with an increased rate of ring growth following trunk injection are indicated by an asterisk (*) while trees with a decreased rate of ring growth are indicated in bold text (P = 0.05, paired t-test).
| Tree | Insecticide g ai/g formulation | Treatment year | Canopy thinning and dieback (%) | Cambial injury (cm2) | Wound closure year 1 (%) | Wound closure year 2 (%) | Ring growth (cm) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2006 | 2007 | 2008 | 2009 | Before injection year 2 | Before injection year 1 | After injection year 1 | After injection year 2 | ||||||
| 1 | Emamectin 0.04 | Autumn 2005 | 3 | 8 | 5 | 0 | 3.0±1.1 | 44.1±9.5 | 79.8±10.3 | 0.34±0.09 | 0.38±0.20 | 0.58±0.18* | 0.44±0.17 |
| 2 | Emamectin 0.04 | Autumn 2005 | 0 | 23 | 25 | 13 | 4.2±0.5 | 42.4±4.3 | 90.0±0.0 | 0.75±0.24 | 0.75±0.31 | 0.93±0.17 | 1.28±0.21* |
| 3 | Emamectin 0.04 | Spring 2008 | 25 | 10 | 10 | 10 | 5.8±8.0 | 47.6±30.7 | 71.6±26.8 | 0.70±0.27 | 0.65±0.47 | 0.78±0.49 | 0.63±0.32 |
| 4 | Emamectin 0.04 | Spring 2008 | 15 | 5 | 13 | 5 | 2.9±0.6 | 45.5±12.2 | 80.3±17.3 | 0.84±0.32 | 0.70±0.40 | 0.76±0.17 | 0.68±0.16 |
| 5 | Imidacloprid 0.05 | Autumn 2005 | 13 | 3 | 40 | 60 | 3.8±1.1 | 36.3±4.8 | 73.7±10.6 | 0.80±0.07 | 0.82±0.15 | 0.74± 0.13 | 0.76±0.19 |
| 6 | Imidacloprid 0.05 | Autumn 2005 | 3 | 3 | 10 | 55 | 1.2±0.2 | 80.3±11.2 | 90.0±0.0 | 1.00±0.28 | 1.05±0.30 | 0.93±0.19 | 0.65±0.10 |
| 7 | Imidacloprid 0.20 | Autumn 2005 | 5 | 8 | 23 | 55 | 2.6±0.5 | 38.4±3.8 | 74.6±11.4 | 0.43±0.26 | 0.43±0.33 | 0.58±0.05 | 0.55±0.19 |
| 8 | Imidacloprid 0.20 | Autumn 2005 | 5 | 10 | 38 | 83 | 2.2±0.8 | 71.8±17.1 | 90.0±0.0 | 0.96±0.21 | 1.10±0.17 | 1.26±0.27 | 1.10±0.07 |
| 9 | Acephate 0.97 | Spring 2006 | 8 | 8 | 10 | 30 | 3.5±0.9 | 49.0±9.9 | 82.1±10.2 | 0.90±0.23 | 0.93±0.21 | 0.88±0.17 | 0.70±0.27 |
| 10 | Acephate 0.97 | Spring 2006 | 0 | 20 | 20 | 80 | 4.1±1.1 | 46.3±7.0 | 80.0±13.0 | 0.86±0.13 | 0.74±0.17 | 0.94±0.05 | 0.56±0.05 |
| 11 | Imidacloprid 0.20 | Spring 2008 | 10 | 10 | 25 | 18 | 5.6±3.5 | 27.5±6.0 | 40.0±19.7 | 0.68±0.15 | 0.68±0.13 | 0.48±0.05 | 0.18±0.20 |
| 12 | Imidacloprid 0.20 | Spring 2008 | 45 | 40 | 50 | 48 | 3.6±1.9 | 27.7±9.3 | 39.1±7.2 | 0.44±0.15 | 0.50±0.27 | 0.36±0.09 | 0.14±0.13 |
| 13 | Imidacloprid 0.05 | Spring 2008 | 5 | 5 | 25 | 5 | 7.7±6.1 | 33.1±14.9 | 64.1±29.1 | 0.63±0.19 | 0.60±0.32 | 0.65±0.29 | 0.63±0.30 |
| 14 | Imidacloprid 0.05 | Spring 2008 | 38 | 28 | 18 | 30 | 2.8±0.7 | 56.7±18.9 | 87.7±5.2 | 0.80±0.16 | 0.88±0.13 | 0.94±0.13 | 0.76±0.19 |
| 15 | None | - | 38 | 58 | 60 | 88 | - | - | - | 0.13±0.05 | 0.07±0.01 | 0.06±0.02 | 0.09±0.02 |
| 16 | None | - | 15 | 20 | 88 | 100 | - | - | - | 0.13±0.03 | 0.27±0.04 | 0.23±0.17 | 0.06±0.08 |