Eucalyptus Trial, Hamilton, Victoria

Independently Conducted by Weedensol*

Aim: To evaluate the growth response of Great Land in blue gum (Eucalyptus globulus) plantations.

Design: Randomised replicated trial with 4 replicates per treatment. Each replicate contained 10 trees planted in a 50m2 plot. One tree strip was planted between treatments as a buffer.

Treatments: Six separate Great Land treatment programs were performed. Treatment events are described here and specific application rates** are tabled with the assessment results below.

  • ‘Seedling Drench’: Seedling trays drenched in Great Land (diluted at 1 in 10) 48 hrs prior to planting.
  • ‘At Planting’: Great Land sprayed on soil, 1 metre either side of the tree line, prior to planting on the same day. Seedlings planted 14 July 2015.
  • ‘2 Month Post’: Great Land sprayed on soil, 1 metre either side of the tree line two months after planting.

Assessments: Tree volume was assessed at 12 months after planting. Tree health/ vigour and insect presence was assessed at three points in the first year.

Conditions: Rainfall was lower than regional average. Soil moisture conditions varied throughout the trial area. Trial trees were planted several weeks prior to remainder of the plantation therefore subjected to higher than expected animal browsing pressure. Data analysis was only conducted on surviving trees (70 – 97% of total planted) to reduce the variability due to browsing loss. Weed control was effectively managed. Trial trees were not treated with ‘Shield’ (systemic insecticide).

Results: Tree volume at 12 months was significantly greater for Great Land treatments at high rates of application. Economically, the most favourable treatment program is T3 – seedling drench and one Great Land spray on soil @ 20L/ha at the time of planting.

Tree health/vigour scores at the high Great Land application rates (T3 and T5) were better than other treatments, however the differences were not significant.

Conclusions: The trial showed strong evidence of the positive effect of Great Land on tree growth measured at 12 months after planting. Unfortunately, the planned 24 month assessment was abandoned due to ongoing effects of browsing losses on variability. The study is worthy of further investigation given widely accepted positive associations between early tree development and ultimate harvest yield.

* Weed & Environmental Solutions, Victoria. Full report available on request.

** Trial application rate equivalent to new Great Land formulation, released December 2018.