Apple Trees again - Biennial Bearing

[sime42]

So this tree seems to have set itself firmly in a Biennial Cropping routine. There were hardly any flowers/fruit last year, and too many the year before. Now it's inundated again. They're big apples as well, no way the tree will take it if even half of them set.

 

Any advice on how get it out of this pattern, reset the tree to a more balanced annual cropping? Thanks. Is it even possible?

 

[Peasgood]

It is a balance of pruning, fertilising and thinning of the fruit. Important to pick the fruit when ripe too, don't let them just fall off.

If it is over set this year then pick off the extra fruitlets later this month and leave them spaced out enough for them to grow to the best size, so 1 fruit every 4" for example. You can do this when they are about the size of a grape. (you can do it whenever you like but the earlier the better but big enough to be sure they have set and not going to fall off with June drop.

It also looks to have very little growth, a bit more pruned off in winter would encourage growth although it does look to be a dwarfing rootstock so not easy.

I have been doing this professionally all my life and still not there 100%.

[daltontrees]

NIAB says this.

Overcoming biennial bearing

With varieties that have developed a biennial pattern of cropping growers should:

• Prune away excessive spurs in the winter prior to an ‘on’ year.
• Thin blossoms on biennial varieties in the ‘on’ year.
• Thin, preferably at flowering time, using ATS.

No chemical treatments, other than thinning treatments are approved for use against biennial bearing

[sime42]

Thank you both. So it's by no means a simple matter to resolve. Shame, but to be expected.

 

I'll start off by thinning this years fruit. Slightly confused about doing the blossom vs the fruitlets though. What's the harm in doing it now, at the blossom stage, other than the risk of ending up with too few fruit due to the June drop and some flowers not being set?

 

@Peasgood - there is actually plenty of vegetative growth always, too much probably. I've pruned if off already, I think I did it late last winter. The form of the tree is still very much WIP! It is on a M106 rootstock if I remember rightly.