The FRUIT GROWTH (FG) app by Joe Ferri – and mentored by his grower brother Tom of TK Ferri Orchard, The Blue Mountains, Ontario, CANADA – is an iPhone/iPad (only, no Android) app that does just what it says: predict apple fruit set based on the apple fruitlet growth rate model. Per the description on the App Store (https://apps.apple.com/us/app/fruit-growth/id1604255929), the FG app features:
Easy fruitlet size and cluster count input screens.
Quick apple set prediction results screen.
Full results easily shared to email addresses and Mac computers.
The Fruit Growth app accepts fruitlet sizes and cluster counts data to calculate the predicted number of apples that will be set.
The results are summarized in the calculated results screen. The full results Summary file (.csv) can be shared to an email address, internal device storage or air dropped to a Mac computer.
The fruitlet size Data file (.csv) can be shared for cut and paste to the Excel Fruit Growth Model (Ferri version).
I used the FG app in 2022 to predict fruit set in two Gala blocks, two Honeycrisp blocks, and one Fuji block. (Across two orchards, results forthcoming in a pending Fruit Notes article.) I found it generally easy to use and once fruitlet growth measurements are made on a given date it gives instant results predicted fruit set so further chemical thinning decisions can be made. One feature of the FG app allows you to do a split tree (top and bottom) calculation predicting fruit set. As you probably know, fruit set is often better in the tops of trees vs. the bottom. Thus you can target and be more effective with your thinning sprays. Below are a few screenshots from my FG app in 2022 (Figs. 1 - 3), and there are a set of excellent screenshots on the App Store (https://apps.apple.com/us/app/fruit-growth/id1604255929) so you can better understand how it works. For reference, per the Ferri’s, here are their specific notes on how to use the FG app once you download and install:
Fruit Growth Model Notes (Rev 3.0.0)
Select a Variety - to input the fruitlet sizes (Fig. 2)
Input the fruitlet size and Enter button
For fruitlet size measurement accuracy of 0.5 mm (e.g. if 12 is entered 12.0 is stored, if 12. is entered 12.5 is stored)
Note: Once all current measurements are completed, to advance for the next sample date and measurements push the blue right arrow next to the date
When each tree fruitlet measurements are completed:
Enter Clusters button - to input the number of clusters per tree
Input the cluster count and Enter button
If two people are counting the clusters, use the + button to add the counts
Note: To delete all the last sample fruitlet sizes and cluster counts push the Trash button
Add Variety button (Fig. 1)
Enter the variety name
Choose the number of trees to measure
Choose the split or full tree option
(Clusters: Tree Bottom 1-6, Tree Top 7-14)
Save button - save the file name and settings
Manage Files button (Fig. 1)
Select a Variety
Results button - generate the results summary (Fig. 3)
Share Summary button- generate the full results summary .csv file
Delete button - permanently deleted the file
Import Data button - import a fruitlet size Data.csv file
Share Data button - generate the fruitlet size data .csv file
(used to cut / paste into the Excel Fruit Growth Model (Ferri) version)
Joe Ferri is actively updating the FG app, it is up to version 3.0.0. You can download from the App Store, it costs $17.99 but is money well spent. Alone, once set up (see my RECIPE for setting up your trees for using the FG app: https://ag.umass.edu/fruit/fact-sheets/hrt-recipe-predicting-fruit-set-using-fruitlet-growth-rate-model) I can complete a set of measurements per variety/block on a given date in less than an hour. It would go quicker with two people, and you get instant results predicting the fruit set. How good is that?
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| Fig. 1 - FG app iPhone screen “Add Variety/Manage Files” |
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| Fig. 2 - FG app iPhone screen “Enter measurements” |
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| Fig 3. - FG app iPhone screen “Results” |
