The Christmas season is upon us! Many growers have started pruning and are preparing the way for next year’s harvest. We’ll cover some issues we faced this past year and cover some tips to stay ahead for next year. A great way start to preparing for the coming season is to attend the 2016 Western Colorado Horticultural Society conference!! Education is one of our best tools in our ability to constantly be moving forward and maximizing our efforts. Details on this year’s line-up can be found at coloradofruit.org.
This past season once again brought a pair of familiar blights to our industry. Coryneum blight and Fire blight. Both issues rise and fall within the life (disease) triangle of: host-environment-pathogen. If a host is present along with the disease and the weather turns favorable (for the disease) then an outbreak follows. The relevant side of this triangle to our winter season is the pathogen. This is where sanitation will play a role. As you prune though blocks that suffered from one of these blights, pay close attention to removing wood with cankers. With the severity of fire blight in some blocks last season this may mean removing scaffolds or entire trees. During the dormant season, shredding the pruning’s in the alleyway will usually suffice. Removing to a burn pile outside of the block is also good.
We’ll refresh ourselves on the “rules” of pruning. These “rules” were originally developed for pruning apples, BUT… if you’re growing fruit on a tree, these rules will apply. As you read these rules think about the concepts that they were developed from: The most productive blocks are ones that have a minimum of structure wood and a maximum of young fruiting wood. They are also the ones that capture (use) the maximum amount of sunlight from the top to the bottom of the tree. To achieve both of these goals you have to continually remove excess structure wood and cycle in new fruiting wood.
Start pruning the tree from the top downward, outside inward. This removes the chances of a top heavy tree. It forces you to balance the tree and eliminates the chance of leaving too many branches (structure wood) in the top because you pruned too much off the bottom of the tree.
Remove laterals (big branches) with diameters that exceed 50% of the branch they originate from. Look for the “big” branch and cut it out. Look at the tree from a distance before you start to determine which “big” branches need to be removed. This rule applies both to branches originating from the central leader and side branches off of scaffold limbs. This process removes dominating laterals, distributing vigor throughout the tree. A tree with “distributed vigor” will naturally grow more fruiting wood. On pome fruits use “stub” cuts which will produce soft re-growth and fruit buds.
Stub off vigorous uprights to redirect energy and light through the tree. With stone fruits it’s critical to remove these from inside the interior of the tree. On pome fruits a stub cut “upright” will often produce weaker horizontal fruiting structures.
Remove weak, pendant fruiting structures. This rule will help keep the “fruiting wood” in your tree young. Removing weak branches increases light penetration and thins off weaker spurs which saves on chemical or hand thinning later. Weak spurs or fruiting buds often bloom at a different timing, and persist with poor quality crop until removed. Dormant pruning will invigorate the area and direct energy into production of higher quality buds that are better able to withstand spring frost.
Do not allow too many branches in the tree, even if they are below the 50% rule. Excess branches “tax” the system and reduce light penetration. Experience will tell you where the balance is that allows for production of maximum fruit numbers and size.
Prune towards a goal. Have an idea of how many boxes of fruit you want to harvest off of each acre. Work that number backwards to determine how many fruit per tree you need, then prune towards that number. Prune a few trees and count the fruiting sites left. Following this rule will reduce your thinning bill and increase your fruit size. Put a note on your calendar to count fruit per tree just prior to harvest. This timing allows you to judge crop load and fruit size. TAKE NOTES! When pruning and thinning time comes around the following year you will be able to take most of the guessing out of your work.
All of us who farm have one of our most critical “inputs” delivered to us daily at no cost! SUNLIGHT. Sunlight is what drives the system. It’s what gives your fruit taste, size and color! Following these rules will help you take full advantage of one of your greatest resources, the sun.
If you have questions about these rules, let us know and we’ll explain them further. I’d be happy to demonstrate them on your place. It’s a good time of year to plan for the coming season, if you would like to discuss herbicides, fertilization, or pest programs give us a call and we’ll stop by.
Here are a few key factors affecting the production/profitability of a block of fruit:
Tree spacing, rootstock, and variety – Maximizing the amount of sunlight captured by each acre should be part of your production goal. The right rootstock/variety combination planted at a spacing that will fill the orchard acre is vital to your success. Too much blue sky between the tractor and tree row cuts down on your harvest.
Weather – While there are certainly some sites better than others when it comes to spring frosts, I don’t know of any completely frost free sites on the West Slope. Is fighting frost part of your production goal? Do you own a wind machine? Is it ready to run for one of our minus zero winter nights?
Soil - How deep is your soil? A lot of us farm on shallow calcareous soils. Twelve to eighteen inches of topsoil is all we have to work with. I’ve observed a number of fifty plus year old trees pushed over that had root systems only two feet deep. It’s an accurate analogy to say we farm trees in pots. This fact should be considered in our decisions regarding nutrition and irrigation.
Pest and Disease – Does you production goal have a pest/disease threshold? Are you willing to accept some level of damage? Do you understand the impact a pest population this year can have on next season’s crop?
“We must find time to stop and thank the people who make a difference in our lives”
-John F Kennedy
There’s no better time than the Christmas season to stop and say “thanks”.
You make a difference for us.
The crew at Cropworx wishes you a Merry Christmas and a great big
for your business!