Answer: Here are a few suggestions. Squirrels are smart and will catch on to scare tactics (like the fake owl) so you'll probably need to use a combination of tactics.
Scare devices: Hang scare eye balloowns, fake owls, flash tape or even old CDs (their shiny surfaces reflect light) in the branches.
Exclusion: You could try covering the tree with bird netting; however, the squirrels may be able to chew through it. And you'll have to secure it around the trunk so the squirrels can't get in.
Depending on how low the lowest branches are, you could create an inverted cone shield around the trunk to prevent the critters from climbing. However, if the lowest branches are within squirrel jumping distance -- or if there are other trees around that the squirrels could jump from, this wouldn't help.
Repellants: There are commercial rodent repellants available; read labels carefully to make sure the repellant is labelled for use on fruit trees. However, you wouldn't want to spray anything on the fruit to make it taste bad, so this may not be an option.
I hope this helps!
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