Project Outline A demonstration site was set up in a block of 3 year old Fierro Fuji’s grafted onto 10 year old M.26 rootstocks (previously Sundowner) still filling their allocated canopy area. The trees are drip irrigated. A root pruning demonstration site was set up in the most vigorous part of the block. The site had the following treatments Control – no ripping Ripped both sides Single Ripped – North side Single ripped – South side
Trees at ripping time
The ripping lines were a vertical incision 500mm from the trunk and 400mm deep.
No measurements of fruit yields or characteristics Trees in their first significant crop year whilst still developing tree canopy. Crop yield was t/ha Planned netting was added to the block during the growing season. Trellis extensions had already been added to support the leaders The height of the net is 4.5 m above ground level. All of the trees have attained the desired tree height in their 3 rd season.
Control Trees – end of growing season
Trees Ripped South Side
Ripped North Side
Results Summary** (averages of 20 measured trees) MeasurementControl Ripped North Side Double Rip Ripped South Side Starting Circumference (cm) End of season Circumference (cm) % difference - tree circumference Tree Height (m) Number of Branches above 2.5 m*
Apart from Slight reduction in tree circumference for the North side ripped treatment Slight reduction in tree height for North side ripped treatment and a significant (approx 27%) difference in actual branch numbers (>5cm long and above 2.5 m) for the ripped trees there was no appreciable difference in tree performance. Discussion
Concluded that whilst the treatments may have had some small impacts the 3 ripping treatments did not significantly influence tree canopy development in this season. North side ripped treatment?
Where were the roots before ripping? (Drip irrigated block)
Dig and find out where the roots are before ripping – don’t guess! If you don’t know – you cannot get the impact you want Or worse – you could get too severe an impact.