NEWA apple carbohydrate thinning model now improved!

Written by Dan Olmstead, Juliet Carroll and Mario Miranda Sazo

You’ve read about it in trade magazines, heard about in talks, and now it’s become a reality with a v2019 upgrade released on Friday April 26! Terence Robinson has added important improvements to the apple carbohydrate thinning model on NEWA. Dr. Robinson, tlr1@cornell.edu, Professor of Horticulture, Cornell University, along with other horticulturists, developed the Malusim fruit thinning model. The Apple Carbohydrate Thinning Model on NEWA has continued to be researched and now the improvements from this research are being woven into a v2019 edition of the model, improving its precision.

How to Access the v2019 Apple Carbohydrate Thinning Model on NEWA

If you haven’t already started your thinning program, access and use the v2019 apple carbohydrate thinning model using the same dropdown list as the current apple thinning model. Click on ‘Apple CHO Thinning v2019 NEW’.

If you’ve already initiated your thinning program and are using the original ‘Apple Carbohydrate Thinning’ model, continue to use that one. All web browser bookmarks and website access points will remain intact for the remainder of 2019.

Need more specifics? On NEWA’s main menu, hover over or tap on ‘Crop Management’ to show the dropdown list. Then click or tap on ‘Apple CHO Thinning v2019 NEW’. Click the link below for direct access.

Apple CHO Thinning v2019 (the upgraded version), http://newa.cornell.edu/index.php?page=apple-thin-new

Mario Miranda Sazo, Extension Associate, Cornell Cooperative Extension Lake Ontario Fruit Program, provided this summary of the upgrades in the Apple CHO Thinning v2019 NEW model.

  • The NEWA apple carbohydrate thinning model will get an updated look and provide more comprehensive information.
  • The data table will have a column of degree days (DD) base 4°C and will have color highlighting when we are in the sweet spot for thinning (200-250 DD from bloom).
  • The user will be required to enter the percentage of spurs that are floral.
  • The new version will also give a Thinning Index composed of the average carbohydrate balance for the two days before, the day of thinning, and the next four days, providing a seven-day running average.
  • The thinning recommendations will be based on a new three-dimensional lookup table that takes into account DD from bloom, percent of spurs that are flowering, and the thinning index (i.e. the average carbohydrate balance over seven days).
  • The thinning recommendation cells in the table will be color coded to indicate high risk of over-thinning (red), mild thinning efficacy (yellow), and good thinning efficacy (green).

In New York, please direct questions and comments regarding these important updates and changes to your Cornell Cooperative Extension regional program extension educator listed below or to Terence Robinson.

Mario Miranda Sazo, Lake Ontario Fruit Program

Mike Basedow, Eastern New York Commercial Horticulture Program (Champlain Valley)

Dan Donahue, Eastern New York Commercial Horticulture Program (Hudson Valley)

In 2020, along with a brand new NEWA website, the upgraded apple carbohydrate thinning model will be implemented on NEWA and replace the original version.