Rootstock Percent Tree size Cold hardy Bud 9 15 to 25 R Good Mark 25 Good M.9-Fl.56 <30 Tol G.11 <30 Tol R Yes Good G.41 30 YES Very Tol R Yes Yes M.9-337 30 Tol G.214 35 YES Very Tol R Yes TBD 1 M.26 25 to 40 Good G.210 35 YES Very Tol R Yes TBD 1 G.935 35 YES Very Tol R Yes M.9 Emla-Pajam 2 35 Tol Rootstock Traits 2013 Replant Root rot How Fireblight to use the Woolly Pollen resistant resistant Tube Resistant Growth Resist Model Jim McFerson Washington Tree Fruit Research Commission G.222 40 Tol R Yes Yes M.9-Nic Larson, 29 Roche 40 Fruit Co, Inc., Yakima Tol G.969 40 YES Very Tol R YES TBD 1 Schell, Chelan Fruit Co, Chelan G.890 45 YES Very Tol R Yes TBD 1 G.30 45 YES Very Tol R Yes Adam Zediker, Washington Fruit and Produce, Yakima 1 McFerson 2 1
McFerson Parts of the Stamen Anther Filament 3 McFerson Parts of the Pistil Stigma Style Ovary Receptical 4 2
McFerson All models are wrong, but some are useful 5 How do you use the pollen tube model? 6 3
Pollen tube Growth Model Enabling tool to help me make multiple blossom spray timing decisions along with visual observations. 7 Chemical Thinning Objectives Number 1 is a return bloom Reduction in hand thinning but not necessarily elimination. Producing a consistent volume and quality parameter crop. 8 4
Adam How do you use the pollen tube model? I use it to prioritize and plan: If all is going well it can help me determine what block to spray first It really helps time the 2 nd and 3 rd and 4 th sprays during bloom 9 Adam Grower inputs 1. Determine desired crop load 2. Looks for open Kings in middle 2/3 of tree 3-4 apart 3. Measure 25-50 style lengths gathered throughout the block ASAP 4. Check the model routinely during bloom 5. Be aware of number of potential flowers 6. Use your head / common sense 10 5
2012 11 12 6
13 2013 14 7
15 DIFFERENT GROWING SYSTEMS MAY REQUIRE A DIFFERENT APPROACHS ON LARGE FREE STANDING BLOCKS COUNT TAGGED LIMBS OR VISUALLY ESTIMATE KING BLOOM OPEN ON TRELLIS BLOCKS WHOLE OR PART OF TREE MAY BE COUNTED OR VISUAL ESTIMATE MAY BE USED 16 8
How do you collect the style length data? 17 STEP 1-ABC s OF DETERMINING KING BLOOM AVERAGE STYLE LENGTH A. KING BLOOM STYLE SAMPLES SHOULD BE TAKEN AS EARLY AS POSSIBLE TO ESTABLISH AVERAGE STYLE LENGTH OF VARIETY BEING TESTED. 18 9
STEP 1-ABC sof DETERMINING KING BLOOM AVERAGE STYLE LENGTH B. RANDOM FLOWER SAMPLING OF 25 50 FLOWERS ARE NEEDED TO ATTAIN AVERAGE STYLE LENGTH FOR TEST BLOCK AREA. 19 STEP 1-ABC s OF DETERMINING KING BLOOM AVERAGE STYLE LENGTH C. MEASURE ONLY LONGEST STYLE FROM EACH FLOWER SAMPLED (SEE FOLLOWING SLIDES). AVERAGE LENGTH OF STYLES IS THEN USED AS BENCHMARK FOR FLOWER FERTILIZATION POINT FOR POLLEN TUBE GROWTH MODEL. 20 10
IN SOME VARIETIES (AS SHOWN ABOVE) STYLES MAY BE LONGER THAN ANTHERS WHILE IN OTHER ANTHERS MAY BE LONGER THAN STYLES. 21 STYLES MAY BE REMOVED FOR MEASURING. CUT AT LOCATION SHOWN. 22 11
AFTER REMOVAL MEASURE ONLY LONGEST STYLE ON EACH FLOWER SAMPLED. 23 Adam How do you collect the style length data? Digital Micrometer 25-50 flowers that are needed to keep a crop 24 12
Style Length Collect 25 kings as the first ones are opening. Measure just below the sepals to the longest style for that flower in millimeters Add all 25 longest styles and divide by 25 to get an average style length for that variety. Enter that information into the AWN pollen tube model site for your selected weather station and model. 25 26 13
How do you establish the fruit set to start the model? 27 When to start the model? Starting the model may depend on the fullness of bloom for that season. Consider bee activity and frost injury to determine fruit set. Under ideal conditions in heavybloom years start: by count of flowers/tree with bee visits in trellis blocks large trees by estimating when 1/3 of the kings open average through the tree If bloom ~50% of a full heavy bloom, delaystarting the model until 80-100% of kingsopen. 28 14
Adam How do you start the model? Start the model at the moment there is enough bloom open with bee activity to make a full crop. If I did proper pruning and weather is agreeing with me (~70 o F daytime) that moment is about 80% KING bloom(4 of 5 clusters with kings open)bloom. If I need side bloom (a few doubles after fruit set) that could be 40 % FULLbloom or if I didn t prune hard enough (TOO many king flowers) it could be 30% KINGbloom. 29 Adam Hypothetical example Gala block where larger fruit is desired Spacing: 3 x 12 = 1210 trees/acre Desired yield: 60 bins peaking on 88s 60 bins x 24 boxes x 88 fruit = 126,720 fruit/acre or 105 fruit/tree As soon as typical trees have 105 flowers open, start the clock (activate pollen tube growth model) 30 15
Adam Hypothetical example continued Apply first bloom thinning spray when model hits 100-110%of mean style length the timing of this spray determines your fruit set Entering spray timings reset the model to track tube growth in newly opened flowers All subsequent sprays should be made when model is no more than 75%of style length to ensure no more fruit set Strategy may be different in other scenarios (e.g. you want to set more lateral bloom) 31 32 16
Good spray timings 33 Bad spray timings 34 17
SUBSEQUENT THINNING SPRAYS SHOULD BE APPLIED AS NEEDED BEFORE MODEL PREDICTED POLLEN TUBE GROWTH REACHES AVERAGE STYLE LENGTH 35 36 18
Variables to consider to implement the model? 37 Suggestions for first uses Talk to a someone who has experience with the model Try it on a small block Make a dry run follow the model normally without spraying according to model timings Use the model to do a post mortem of your standard programs by entering those spray timings Play with it online before thinning season 38 19
Model limitations Assumes optimal bee activity and pollen availability/viability No models for secondary or niche varieties Unresolved questions about role of pollen source Normal use requires overly simplistic assumptions about efficacy of chemical thinners 39 Adam Model limitations Assumes optimal bee activity and pollen availability/viability **( No Bees working but open bloom: Delay model start until bees work. )** No models for secondary or niche varieties Unresolved questions about role of pollen source Normal use requires overly simplistic assumptions about efficacy of chemical thinners 40 20
Variables to consider Should I use my own weather data from my orchard or a nearby AWN station? What has been my bee activity, frost, pollen viability been like? What varieties am I planning to use it on and are there models for them? What other post bloom options do I have? 41 2012 Apr 23 May 3 2013 Apr 21 May 3 2014 Apr 22 May 1 42 21
2014 spring and questions on model Model didn t seem to coordinate with what was happening in the field. Need more research on what is happening under cooler adverse conditions. Does exposure and radiation affect the model? 43 How has PTGM changed your chemical thinning programs? 44 22
Changes due to PTGM Reduced the amount of post bloom applications. Improved return bloom and consistent cropping. Enabled hand thinning to occur later in the summer(after cherry harvest) and not affect apple quality parameters (size and color). 45 Production on Golden s for 3 years use of the model 2012 2013 2014 2015 Bins/acre 92.6 107.4 123.4? Boxes/acre 2,092 2,428 2,789? 46 23
Adam Suggestions for first time users: Talk to a consultant or someone who has experience with the model Try it on with a small block Make a dry run follow the model normally without spraying according to model timings Use the model to do a post mortem of your standard programs by entering those spray timings Play with it online before thinning season 47 Heavy pollen tube burn 48 24