Fruit Grower News 

 

January 2019

 

 

 

Happy New Year!!!

 

This time of year always provides for many good learning opportunities via seminars, conferences and the like.  Here’s what’s coming up right around the corner;

 

January 15-17, 2019

 

The Western Colorado Horticultural Society (WCHS) and VinCO conference and trade show is almost here!  This is a great opportunity to mingle with other growers, meet new people, learn new things, see new and improved materials and equipment and the list goes on! Join the conference at www.coloradofruit.org, be a part of the ag community and increase your knowledge of the industry.  This year’s lineup includes important talks on:

 

-Soil health: the path to more water and enhanced nutrients

-Good soils lead to more efficient and resilient production

-Limited tools, multiple strategies: managing pests while extending the life of our tools

-Secondary pest management should not be a defensive position

-Retail trends for the fruit industry

-Big data for small farming communities

-Phylloxera updates

-Cytospera updates

-CDA/FDA FSMA updates

…plus many more including an open panel discussion and a great keynote session on “Planning for an Uncertain Future: Drought Contingency Planning, Demand Management, and West Slope Agriculture.”

 

The bus tour is a fun and informative opportunity to see how farms in Mesa and Delta counties operate, what techniques they’re utilizing that could positively impact your farm and just a great time to get to know the speakers and other growers.  Check out the WCHS website above for the full list of speakers and session descriptions and sign up today!

 

How cold was it?

 

Last night brought temps around the region from -6 to -16 degrees Fahrenheit.  I heard a few wind machines running in my neighborhood to protect stone fruit buds.  Cropworx is sponsoring the bud hardiness program this year in conjunction with CSU.  This information alerts growers to the temperatures at which fruit buds are in danger of low temperature death.  Here’s the link to CSU’s webpage where the cold hardiness information can be found:

https://minas.agsci.colostate.edu/tree-fruit-information/cold-hardiness/

 

 

Time to Prune?

As we enter pruning season, let’s keep in mind two big problems that continue to persist each year…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 through blocks that suffered from one of these blights, pay close attention to removing wood with cankers, this may mean removing scaffolds or entire trees.  During the dormant season, shredding the prunings 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.

 

 

“THE RULES”

· 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.  We would 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 your 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?

 

Powdery Mildew Primer

Having this disease in your orchard is like having a low grade fever that just seems to keep you off of your “A” game.  It prevents your trees from performing at an optimal level.  It reduces photosynthesis, shuts down terminal growth, damages or kills fruit buds and can reduce pack out through fruit scarring.   If you’re growing apples, be aggressive with your mildew program!  Don’t let your block be the host for a mildew party!  I pulled the following bullet points from this article on powdery mildew.

https://www.apsnet.org/edcenter/intropp/lessons/fungi/ascomycetes/Pages/ApplePowderyMildew.aspx

 

  • Overwintered infections in dormant flower and shoot buds provide inoculum for the following year.  In spring when the terminal buds begin to grow, the fungus colonizes the young, green tissue as it emerges.

  • Infected flower buds have a silver-gray appearance and open 5-8 days later than healthy ones, if at all.  Petals are distorted and pale yellow or light green.  Blossoms may become shriveled and fail to produce fruit.  Secondary infections may occur on newly forming flower buds, which will remain dormant until the following spring.  Since these buds will be diseased when they open, severe infection can eliminate the crop the following season.

  • Conidia are wind-dispersed and do not require free moisture to germinate.  

  • Extremely low winter temperatures will negatively impact the survival of P. leucotricha as infected buds are more vulnerable to winter kill.

  • Conidia will germinate at high relative humidity (greater than 70%, which is commonly available in the microclimate of the lower leaf surface) at temperatures between 50 and 77°F.

  • In contrast to most foliar fungal pathogens, leaf wetting is a deterrent to infection. 

  • The youngest leaves are the most susceptible, but become increasingly resistant as they mature.

  • Primary infections in flower buds can produce conidia as early as tight-cluster, the stage of apple development when flower cluster leaves start to separate but flower buds remain aggregated .

  • Mildew is a chronic recurrent problem.  High disease levels at the end of a season may (i) increase the percentage of infected buds, leading to high levels of primary inoculum the next spring and/or (ii) inhibit flower bud formation, reducing or eliminating the fruit crop the following season.  Therefore, management of the disease must focus on reducing the primary inoculum and protecting the trees from secondary inoculum.

  • Fungicides are usually applied at 7- to 10-day intervals from the tight-cluster stage until terminal shoot growth ends (about midsummer).  This ensures that fungicide application coincides with rapid leaf development and the post-bloom period, and that the new growth does not remain unprotected for long.  For highly susceptible cultivars, this could mean as many as 18 sprays.

 

 

“Farming looks mighty easy when your plow is a pencil and you’re a thousand miles from the corn field.”

-Dwight D. Eisenhower

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