Once the tree has settled after harvest, there is a good opportunity to provide food, especially if the tree is in storage mode.
The tree stores reserves in the roots and woody tissue and these reserves are critical to healthy growth in the spring.
Post harvest fertiliser (continued from last month)
Many species of tree rely on stored arginine nitrogen for a large part of their spring growth.
This can be applied to the tree in post harvest treatments. Many secondary and micronutrients can also be applied at this time.
Most trees experience a root growth flush after harvest so this is a good time for soil applied fertiliser.
Potassium is important in moving sugars out of the leaf cells and into the phloem.
Magnesium drives the ATPase pump that is integral in this function and boron helps the discharge of sugars, especially when the tree is slightly vegetative.
Calcium applied post harvest will add to the reserves in the tree. Other elements such as zinc, manganese, copper and iron can all be valuable in post harvest conditions and this is a good time to apply these elements to crops sensitive to certain trace elements in the growing season.
Suggestions for Post Harvest
- Avoid practices that will promote vegetative growth close to harvest time such as heavy irrigations or high nitrogen applications.
- Make sure nutrient elements are at optimum levels especially potassium, magnesium and boron.
- Immediately after harvest make an irrigation without fertiliser to reduce stress.
- Follow up with a post harvest nutrient treatment for the tree—this provides the reserves needed for the next growing cycle
- Post harvest nutrients can be applied through the soil and foliage.
Stoller Options
Stoller Australia has a range of options for hibernation.
Where a crop is growing vigorously, a foliar treatment of Sugar Mover can help direct food back to the storage tissue and roots. This is often applied with Stoller’s ZM2 and Foli-Zyme.
In cases where the tree is not adequately returning carbohydrates to the storage tissue after harvest, Sugar Mover has been shown to enhance budburst when used as a post harvest foliar spray.
Through the irrigation, Post Harvest 23 will provide amine nitrogen, calcium and magnesium and if root health is an issue, RootFeed (containing root stimulants) can be used instead.
In season tissue tests will reveal issues with particular nutrients and these identified elements can be added to the Post Harvest 23 fertigation or to the foliar mix. If sodium has accumulated in the tree or root zone, Stoller’s specialty treatments such as RootFeed can displace the sodium, allowing it to be leached out of the root zone over winter.
Prepare now for next season
Remember, the post harvest period is one of the first opportunities to make a positive start for next year’s crop.
A Stoller program combining good management and the necessary reserves for next season might be the answer for you.
There are alternatives for both soil and foliar application to your trees.
See this article in Tree Fruit May 2018
