Table 3 Comparisons between treatments for weed cover (%) within a 1-m radius centred around each tree for the Pinus radiata trial
Treatment comparisons | Difference in cover (%) | P value | Result |
|---|---|---|---|
CTH-Oct vs CTH-Oct x2 (treatment 6 vs treatment 7) | 31.4 | <0.001 | Cover of weeds (%) significantly higher in plots where a broadcast treatment was applied only in spring after planting as opposed to spring of planting and following year |
CTH-Dec vs CTH-Dec x2 (treatment 8 vs treatment 9) | −12.6 | 0.99 | No significant difference in weed cover regardless of frequency when release carried out in summer (December) |
CTH-Dec x2 vs CTH-Oct x2 (treatment 8 vs treatment 6) | 26.1 | <0.001 | Significantly higher cover of weeds at 18 months where release carried out in summer (December) of planting and following year versus spring (October) of both |
Spot control 2 vs spot control 1 (treatment 5 vs treatment 4) | −22.0 | <0.001 | Cover of weeds (%) significantly lower in spot control 2 where an additional release operation was carried out in the spring of the year after planting |
Spot control 3 vs Operational (treatment 12 vs treatment 3) | 22.8 | <0.001 | Significantly higher cover of weeds where terbuthylazine and hexazinone applied as a 1.4-m diameter spot in spring of planting as opposed to an aerial application of same active ingredients |