Observation of pruning effects on fruit production & size

[HarveyC]

I thought I'd share this somewhat isolated but seemingly clear observation I've had on the effects of pruning. As most of you know, I sell a lot of cuttings as well as quite a few trees and for that I must prune my mother trees. I've trained my trees on a low wire after discussing this method with Ken Love in Hawaii who shared his observations from growers in Japan (commonly referred to by others as a "stepover" design, though I find it pretty hard to step over my trees during the growing season). This method requires a lot of pruning, essentially removing all growth down to the wire every year (though I've left some growth for breba fruit).

I have two Col de Dame Noir trees, both rooted in March 2013 and planted in my orchard in early 2014, I believe (my new orchard was started in August 2013 but I don't believe I started this third row that year but may have). In January 2016 when pruning for cuttings I had enough after pruning one tree and stopped with plans to come back later but work never slowed down and I never pruned the second tree this year. When picking fruit for my fig gathering on August 20th I had Gary P, Dan W, and Ross helping me and one of them asked me if I was sure both trees were Col de Dame Noir since one tree had a lot of ripe fruit on it and the other was obviously later. Yes, they were both Col de Dame Noir, the later tree was the one that was pruned. I've since noticed that I was getting some larger Col de Dame Noir fruit than I had in the past and have looked closer and noticed that the fruit size on the tree that wasn't pruned was larger than the one that was pruned. I still get some very large fruits on some varieties of trees that have been heavily pruned but maybe they would be even larger if not pruned.

Most of us don't want to climb ladders to pick our fruit so pruning will be necessary. Also, some of us with longer growing seasons might like the benefit of one heavily pruned tree producing more fruit later in the year. During the Sacramento CRFG scion exchange we had Ernesto Sandoval, Director of the UC Davis Botanical Conservatory, speak to us on the effects of hormones and plant growth and fruiting, etc. I don't recall all the details and it was a busy time, but I recall the changing concentration of hormones due to pruning which leads to increased growth. I'll follow-up with him to get his thoughts on this. I also recall an old radio show program (Dan Pratt, "The Garden Doctor") from 25 years ago or so where the host drilled into us that we should not prune off more than one third of our trees or bushes and maybe this might be a valid guideline when pruning figs.

[fruitnut]

Thank you for those observations. I'll compare some pruning intensities when the opportunity arises.

[AscPete]

Thanks for sharing those observations.

My experience has been similar with potted fig trees, which is why I often recommend establishing the permanent mains and scaffold branches and a fixed quantity (based on container size) of fruiting branches which are the only ones that are pruned yearly.

It appears to be a balance between the roots and canopy, a larger root system will support a greater quantity of fruiting branches, if the roots (mass) are greater than the canopy you may get excessive vegetative growth and later ripening figs.

[don_sanders]

I have noticed that my limited number of second year trees with more pruning seemed to have produced most of their figs rather late and won't have time to ripen this year too. Not enough of a sampling for me to come to a conclusion but something that made me think.

I don't believe that I could get away with only pruning 1/3 or less a year around here though. As fast as they grow, I wouldn't be able to fit them in my garage very quickly. And in ground would be difficult to protect.

I'm hoping that establishing scaffold branches on older trees, limiting fruiting branches, pinching, increased P fertilization, removing suckers, possibly pruning right after fruiting is complete, etc will help me to get a quicker fruit set that will ripen before it gets cold here.

[AscPete]

For potted fig trees, once the mains and scaffolds are established it will be ~ 1/3 (to 1/2) pruned yearly.

[drew51]

I would expect a delay, as you're wounding the plant. Fig size is an interesting observation. Pruning after fruiting I would be afraid the hormones would stimulate growth. Which here with a heavy winter to worry about, would delay hardening off. I myself, like other fruit trees prune while dormant. I do prune fruit trees in the summer too, no reason to prune the fig then though, except maybe to establish scaffolds, otherwise no. I'm getting 30-40 figs on 2nd leaf trees in 10 gallon root pouches with my own soil mix. I don't pinch either.

[RegencyLass]

Interesting. And quite the opposite experience I've had with such fruiting plants as quince, pear and grapes where the more severe the pruning, the larger and more abundant the fruit.

[drew51]

RegencyLass comment reminds me that we never thin figs. Seem well spaced by themselves. Rarely that crowded. With fruit trees thinning results in sweeter, and larger fruit. Might be worth an experiment on an established fig tree?

[AscPete]

The major difference is that figs are not produced in bunches like the other mentioned fruit trees.

[fruitnut]

Interesting. And quite the opposite experience I've had with such fruiting plants as quince, pear and grapes where the more severe the pruning, the larger and more abundant the fruit.

Sorry but that's not my experience. But it's all a matter of pruning severity and timing. Maybe you've never pruned enough to see the down side.


Pears and grapes that are pruned too much bear no fruit. Most fruit trees and grapes have fruiting wood that forms the prior yr. Remove that and you get no fruit. Grapes bear fruit only on wood that formed the prior yr.

What is true is that moderate pruning of the right kind and at the right time will improve fruit production. If those trees and vines aren't pruned at all they tend to set too much fruit that ends up small unless heavily thinned.

[fruitnut]

It's not a climate thing. It's about where the fruiting wood forms. If you've had a vineyard for two decades you should know that if you prune off all of last yrs wood you won't get any fruit. So to say that the more severe the pruning the bigger the crop simply isn't the case. Likewise I could take all the crop off a pear, apple, or peach by over pruning. And I'd still have a tree just minus the fruiting wood.

[HarveyC]

Some of this may be related to climate such as what grapes you are growing (i.e., muscadines in the south). There are tens of thousands of winegrape vineyards here in the Central Valley and they are all pruned to remove all but a bud of the prior year's growth and they fruit on current year's growth quite well Without such pruning the harvest of these vineyards would be extremely difficult and powder mildew would be a much more serious problem. Since figs also fruit the main crop on new year's growth they can fruit well with heavy pruning but maybe later and smaller fruit as I've discussed. Off the subject, but other fruit trees are mostly fruiting on buds formed on older wood with pruning done to manage size and also rejuvenate some new wood to form new buds to replace ones that become less productive. I know that apple pruning methods vary by variety.

[fruitnut]

Harvey:

The one bud you are talking about in spur pruning is last yrs bud. The only buds on grapes that are fruitful are prior yrs buds. Prune those all off and you have not fruit.

With regards to tree fruits such as peach, plum, pluot, apricot, apple, and pear. All the fruit buds are formed in summer on current seasons growth. It appears that some fruit/flowers are on older wood when in fact they are on spurs on older wood. The spurs may only grow 1/8 inch but if they don't grow and form leaves there will be no flower buds set. If the spurs stop growing no flower buds form. That's when renewal pruning is needed. No flower buds form directly on two yr and older wood.

[ThaiFigs]

I wonder if girdling a fruiting branch that you intend to prune later would result in bigger figs?

[Fruitaddict]

Girdling after the fruit forms would result in sweeter and probably larger figs because the glucose produced will not be able to be translocated down the stem to be stored.

[cjccmc]

Only having room for 2 or 3 trees, for me it's more about protecting the fruit from various critters. A size and shape I can wrap with netting will in the end provide more fruit for me the humble grower. A friend in the neighborhood has a tree 10X the size of mine, too big to wrap, so nearly all figs are bird pecked and become a party palace for fruit flies and green beetles. Maybe a farm with acres of trees can overwhelm the critters with volume but here in the burbs it's more about what you can safeguard.

[ThaiFigs]

@Fruitaddict: Probably. But has anyone here tried?

[AscPete]

Sounds like an experiment for a few fruiting branches next season!

[AscPete]

In refering to "Severe Pruning", Harvey's observations are also typical of in-ground trees with severe die-back in colder zones. There is usually rank / excessive growth from multiple buds resulting in reduced and late fig production unless much of the new growth is thinned by pruning, which would also reduce production.

In milder winters the same trees would provide many times more main crop figs with simple tip pruning, which produces many new spring fruiting branches near the perimeter of the canopy on established older wood. They would also provide breba in addition to main crop figs without pruning, but would result in a much larger canopy.