So I was on a call the other day and heard of a California commercial grower who is shooting to size 900 nectarine per tree. My jaw dropped as I didn’t think it possible to size that many fruit per tree… So then I started to do the math and think about both commercial and home growers and their pruning habits. I’ve been tempted myself to try to produce a pretty (structurely speaking) tree, without actually thinking about my fruit goal.
Let’s do some math. If this grower is trying to size 900 nectarines per tree, and we’ll say a 6 inch spacing per nectarine, that comes out to 450 linear feet of fruiting wood left on the tree. At 5 inches, that’s 375 linear feet.
In another instance, I talked to a former grower and he generally had no more than 75 lbs of fruit per tree (let’s say about 200 fruit). I never saw his trees, but I wondered if he was taking off a lot more fruiting wood without thinking of the consequences.?.
Then there is this PSU article that talks about the same approach from a ‘per acre’ target…
The distance between fruit on a shoot or the number of fruit per tree is not very important, but the number of fruit per acre is critical for fruit size. Therefore, if trees are pruned lightly to retain many fruiting shoots, fruit should probably be thinned to at least 8 inches between fruit. Also consider the genetic component of the cultivar for fruit size. In general, early-season cultivars produce smaller fruit than late-season cultivars. Therefore, early-season cultivars should have lower crop loads and this can partially be achieved by retaining fewer fruiting shoots per acre. The optimum numbers of fruit per acre depend on the cultivar and availability of irrigation. For small-size cultivars a provisional number of fruit per acre is about 45,000, which would require 11,250 shoots if the fruit are thinned to 4 fruit per shoot. For medium-size cultivars a reasonable target crop load is 70,000 fruits on 17,500 shoots per acre and for large-fruited cultivars 100,000 fruit on 25,000 shoots per acre is suggested. To calculate the desired number of shoots per tree, simply divide the desired number of shoots by the number of trees per acre. For example, for large-fruited cultivars with a tree density of 150 trees per acre, retain 167 shoots per tree and retain 4 fruit per shoot to produce 100,200 fruit per acre.
Generally, that article doesn’t make any sense to me in that I would think the distance and number of fruit per tree matter a lot…
Obviously, there is also a lot to be said for variety of tree (genetic ability of the fruit, growing tendency of the tree), but I was curious, is this something y’all have thought about when you go into your orchard to prune or thin your trees? Have you thought about the consequences of removing too much fruiting wood?
This year we’re leaving more wood on than I would normally do, My plan is to go back post harvest and make some heavier thinning cuts at that time and do some more corrective pruning.