April 2007
Spring came out of the gates like a race horse and there's no turning back! Are you behind?
Just like spring, a change in your codling moth program is going to start early. If you plan on using an ovacide such as Intrepid, your first cover spray will be about ten days earlier than when you would normally spray. If you've been struggling to keep CM under control in one of your blocks, incorporating an ovicide into your program is sound strategy.
If this season continues to run ahead of schedule you'll need to have your pheremone traps up early. I've already established a biofix for Codling moth in Palisade. Give me a call and I'll you my best guess when they should be put out in your area.
As I write this it's raining on my peach bloom. Is your coryneum blight and/or brown rot program in place? Changes in the weather should give you a heads up that you may need to change your crop protection plans. Wilsonomyces carpophilus, AKA Coryneum blight is far easier to prevent than eradicate! Always be proactive ! The absence of blight at the packing shed costs you nothing!
Albion labs has offered to give out a certain number of free leaf analysis this year. I would encourage you to take advantage of this offer! Albion will run the samples and send you the results back within a few weeks. I would like to have a meeting this fall/winter to review your results and plan a nutrition program for next year. Tree fruits need to be sampled in late July or early August. If you're a grape grower the sample needs to be pulled during the bloom. If you're interested, give me a call and I'll get you set up with sample bags and mailing instructions.
Pear and apple bloom need to be protected against fireblight if conditions warrant. If you have open bloom, sufficient temperature, and rain or heavy dew you could face a blight problem. Keep track of your threat level with WSU's cougar blight model. http://www.ncw.wsu.edu/treefruit/fireblight/2000f.htm
Don't let powdery mildew catch you flat footed. Control is best obtained early in the season. Cherries are best treated at petal fall & shuck fall; peaches from bloom to pit hardening and apples before bloom. There's a wide selection of materials with various modes of action available. Don't fall into a rut and build resistance in you orchard. Rotate materials and start early!
Spring is the most stressful time of the year for any fruit tree. Your orchard is drawing from reserves as it progresses through bloom. Soil temps are cold and limit nutrient availability. Fruit size is partially determined by the number of cells each fruit contains. Cell division occurs immediately after bloom (from 14 to 28 days) when the stress is at it's peak. Healthy, well fed, trees are better able to handle and size large crops, survive winter injury, and pull buds through spring frosts. Next years’ flower buds are determined this season. Keeping a tree well fed is a year round program. Properly timed foliar applications of nutrients can help relief the stress!
Delayed dormant: Zn, Mg & B; Pink, Petal Fall & Summer: N, P, K & CA; Fall: Zn, B, & N
Calcium in adequate amounts is important for the formation of strong cell walls. If adequate calcium is not available when cells are being formed the fruit will be more likely to develop problems later in the season if they are subjected to heat stress. At maturity, with cell walls fully stretched, fruit deficient in calcium will have less firmness and begin to show internal disorders more rapidly than fruit with adequate calcium. Fruit with high calcium is normally firmer and retains good eating quality in storage longer. But there is a real risk that fruit will be low in calcium during cell division. Here’s why. Cell division and development takes place early in the season when soil temperatures are cool and tree roots are not very active. Very little calcium is being picked up from the soil. After the soil warms up and the roots begin to actively support growth, most of this newly available calcium from the soil is passively transported to the most actively growing parts of the tree, leaf expansion and shoot growth, the more slowly expanding fruit cells. What's the take home message here? You have a window of opportunity open NOW. Add calcium to any spray applications made during the cell division period.
I came across an excellent set of spray programs for organic growers. They're set up like the Washington state spray guide, moving from one crop stage to the next. They list the diseases and pests present at each crop stage along with suggested control measures. The guides cover apricot, peach, apple, pear and cherry. Let me know if you want a copy.
In today’s fruit industry, top quality is not an option — it is a requirement.
As always, call with any questions! Larry 234-3424