Focus Orchard Trial: Establishing Tree Height on Young Pink Lady Trees
Orchard: Lenne’s Orchards
Orchardist:Matthew Lenne
Prepared by:Virginie Grégoire and Michael Crisera, Fruit Growers Victoria Ldt.
Why we decided on this trial?
Comparelevels of canopy developmenton 2nd leaf Rosy Glowunder different treatments; manual flower removal in top 0.5 m of trees,complete fruit removal and chemical thinning (control).
Block Background
The block is Rosy Glow planted in 2012 on M9 rootstocks. It is being trained on a slender style with a spacing is 1mby 3.5m and trees are supported by wires evenly spaced. At the time of trial they have not had a commercial crop yet.
Treatments
- Control: Only chemical thinning applied on these trees.
- Manual flower removal: Done twice during blossom. Only flowers in the top 0.5m of trees were removed. Chemical thinning was also applied on these trees at the same rate as the control.
- Complete fruit removal:All pieces were removed after fruit set on all trees for this treatment.
Chemical thinning (for Control and Manual flower removal treatment)
7th October: ATS every second row
9th October: ATS every other row
18th October: Carabryl + BA
What have we learnt so far?
If we were going to profile every treatment, all three of them have their own advantages to suit different strategies. If the main objective was only to reach optimal tree height then, as expected, thinning flowers in tops and removing all fruits are the best options. Since canopy development on 2nd leaf trees is also about establishing good fruiting limbs, let’s have a look at the highlights for each treatment.
-Control (Chemical thinning only): The leader extension is moderate, on average 10-12cm less than the other treatments howevermoreof the shorter shoots. On average 50% more shoots provides an opportunity for the grower to select the best wood at the right position in the tree for a highly controlled system. Theoretically, this strategy also leads to a higher production tonnage.
-Flower thinning (in top 0.5 m only): This treatment led to much less overall growth but most of it being concentration in the leader. While the control had bent tops due to the weight of the fruits, trees under this treatment had straight top reaching for the last wire.
-Complete fruit removal: Similar to flower thinning in terms of leader extension and shoot number per tree but much more overall growth which means every shoot (except the leader) is longer.
Conclusion
This trial shows that definitely, a block in its 2nd year should have some blossom or fruit removal in addition to regular chemical thinning so they reach the optimal height at quickly as possible. While blossom removal at the top of the trees mainly improves leader extension, complete fruit removal will promote overall growth hence help establishing good fruiting wood. Depending on the type of planting and the limb length a grower is looking for, overall growth promotion may or may not be the best practice on 2nd leaf. In fact, it may not be necessary in an extensively high density block where short limbs are ideal.
Trials like this one help understand the impact of different crucial practices early during the establishment of a block to optimise profitability.