Two new predictive models to help apple growers with chemical thinning decisions on their Granny Smith and Honeycrisp trees are available to the public this year.


Tree Fruit Research Commission’s Tory Schmidt said it will allow for growers to know when to apply their chemicals for crop load management based on ambient temperature and other weather patterns.


“So if they know a certain proportion of their flowers should be set or be fertilized then they can dial in more closely how many flowers or fruit that they want to leave behind when they put on their chemical thinners.”


The predictive models can be found on AgWeatherNet’s website with more varieties also available.


Schmidt said while the reaction has been mixed to these tools, part of it is just getting producers to understand how they work.


“Most folks who are working with the models are having enough success that they are expanding their use every year and so it continues to have more and more uptake by industry every year.”


WSU is beta testing a model for red delicious, something Schmidt noted was the most difficult of the all the varieties, and hopes to have that available to the public next year.


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