This week I’m tending my orchard and nursery, pruning, mulching, straightening trees and the like. Flower set is extremely heavy this year with lots of open apple flowers- and I’m going after some of those flowers on varieties particularly susceptible to biennial bearing that I’m almost certain will way overset fruit this year.
For Spitz and Goldrush, I thin the flower clusters to about 4" apart usually leaving more than half of the spurs devoid of fruit. They can begin storing energy for next years flowers now. This technique has worked very well for me. I will do more thinning about a week after petal fall, leaving only a single fruit on each spur holding them. I will then gradually thin fruit to about one apple every 6-8".
For a later season apple it is not strongly prone to biennial bearing but there are many variables beyond just how heavy the crop is. Have you tried trapping out the hornets? We have a variety of very large hornets that doesn’t appear in my orchard but is in orchards I manage closer to the ocean. They will go into wasp traps baited with 30% concentrated apple juice. There’s little doubt they’d work on any wasp or hornet going after apples.
Here, Fuji is the one of those that is most prone to biennial bearing. It is well known to growers in my area as being so. I am talking about as grown on trees with vigorous enough roots to stand without support, not dwarfs.
I’ve noticed that established trees on seedling rootstocks seem less prone to biennial bearing. GD is probably the least vigorous of those varieties, so maybe the problem is not enough vigor.
Mine definitely tends to biennial. I had about 30 apples on a fairly small tree year before last and none last year. Assuming I get a good set I’ll thin more this year. It’s one I usually eat off the tree and I like the long fruit bearing period.
It has an open airy look compared to my other trees and I like that. Sorry for the post. I ran into it one year with the lawnmower and I’ve been trying to straighten it ever since.
