Well, by these standards, about a 60% deficit is normal for unirrigated trees in the east, given summer months average under 4" rain a month. Of course, the data you give is only part of the factors involved. Humidity, heat and levels of sunlight would be important. Also commercial recommendations are likely based on bare soil. However, it is interesting that on years where we get less than normal rainfall and mostly sunny days, NY growers are doing serious deficit fruit production. We’ve had growing seasons like that for the last 3 before this one. Unfortunately, last year, hard late frost didn’t allow much exploitation of the very good fruit growing conditions. The year before that, it was almost like CA conditions. I doubt I will live to see another growing season here as good as that one. Perfect weather and almost no pest pressure, from insects, through birds, squirrels, coons and deer. They all left fruit alone for a season.
The front yard orchard is 3 years old, trees 4, so I have not reapplied bark yet as it was spread at least 3 inches deep. Our last rains this season were in mid April, and was a very wet winter so soil probably didn’t dry as early as usual. It gets very windy in April and may, this drys the soil, and is usually mid 90s by mid may. By this time our soil is bone dry and the deficit is well underway. I think May 1st would be my best guess on when the deficit begins. My best fruit of the season is harvested from mid June through august .Our first and most intense heat wave always hits in late June, at our summer solstice. This year was brutal 10 days with an average of about 105, and peaking at a record 111, global warming. Its hard to say exactly when that deficit starts, but I think southern, full sun exposure is critical as well as deficit watering, combined you should have premium fruit. I will never have Fruitnuts 30 brix cherries here with my very wet springs though, I’m jealous! His early season fruit is untouchable!! I also have to deal with a bunch of pests here that make tree ripened fruit tough. Between the birds, bugs, and specifically dried fruit beetles, I only get to harvest about half my fruit. The fruit I find the beetle in has been spoiled from the inside out, kinda like brown rot. They spoil the entire fruit, and to get rid of them you must bag and dispose the infected fruit imeadiately. Everything is not all good in California, we have our challenges as well!
This has been an extremely interesting discussion to me. Before it started, I didn’t even know that typical CA growers use nearly the amount of water Fruitnut describes- I thought the main difference in quality between my fruit (on a decent year) and that from CA was that I let fruit fully tree ripen. I also had no idea that at least some CA growers had to contest with pests that make keeping fruit on the trees long enough to get highest quality without keeping poison on them extremely inefficient- only a home grower can afford to throw away half of their fruit.
As a very young man in CA in the area where I was raised- the foothills a few miles from the Malibu shore, I enjoyed water deficit fruit without knowing why it was so good- it was merely neglected. Back then, the only significant pests were coons and squirrels.
I doubt your more extreme heat is needed to reach the high levels of brix you achieve, but establishing that would require comparison to CA growers with more coastal influence than what you have, that use your methods. I’ve long thought that the best fruit growing parts of CA have been wasted to grow wine grapes!
I am left with a sense that something should be done to discourage commercial CA fruit growers from using the insane amount of irrigation water they do just so they can sell a very small percentage of that water by essentially adulterating their fruit with it- they might as well just inject the water directly into the fruit before distribution- at least this would save millions of gallons of wasted water. Orchards should at least have to post the average brix of their fruit on the boxes that contain it.
All this talk and numbers, and such looks good on paper, but when my wife says “that’s the best plum I have had in a decade” I think that tells it all for the fruit here this growing season.
You may be a fruitee, but you are no fruit nerd.
I just harvested a Honey Royale with 20 brix that wasn’t even ripe. Picked it just to measure before the yellow jackets destroyed it completely. This variety is impossible to protect so far because it has born such light crops of no-acid fruit any kid, insect or chipmunk would love. . I’m still trying to figure out if I can manage it productively here. If I can, I will decide if I like it’s intense sweetness without acid later. It tastes like something grown in the tropics, not like natural temperate climate fruit. Designer fruit for babies weaned on corn syrup.
Only kidding, Fruinut. I know it’s one of your favorites.
A lot of growers are using flood and sprinkler irrigation and water use can go through the roof really fast with these methods. With the drought a few orchards have switched to drip, but this is expensive, and their fruit wont be Quite as big, as the consumer cannot try a fruit at the store, you must decide by looks. The fruit loss this year has been a bummer, but by bagging and disposing infested fruit, we will hopefully be able to get rid of these annoying devils. The worst loss is in august, this year has been the worst yet. Organic fruit growing can be challenging, but the rewards are so worth it!! Enjoy those tropically sweet HRs…!!
In the humid regions, it is challenging enough even with limited synthetic interventions. But still “so worth it”.
My sister lives in far northern CA (coastal Humboldt county) and I fired her up yesterday by pointing out how her stolen water is being used by CA farmers to puff up produce while grievously damaging its flavor. I’m hoping to start a political movement, or at least a consciousness, that this practice squanders untold (let’s figure it out) millions of gallons of water just to insert a tiny fraction of it into fruit and other fresh produce. Many of these farmers don’t even pay a fair share for their water.
I’m more than half serious and I’m taking this beyond the obvious waste of water. How many children could be spared a life-time battle with obesity and diabetes if only they were provided fruit from America’s fruit and salad bowl that was actually delicious to eat, with enough sweetness to satisfy their craving that otherwise leads them to eating the dangerous amounts of refined sugar found in industrialized food.
The sugar in fruit is a time release form, held back from our metabolism for gradual release by its cellulose scaffolding, so bears none of the health consequences of products loaded with refined sugar. Fresh, raw fruit is genuinely good for your health, even when eaten glutinously.
While my best peaches are comparable to my best nectarines, my worse nectarines are far superior to my worse peaches. This to me is the defining evidence that nectarines are “just better” 
Anthony
I agree, and would add that the best nectarines are not a replacement for the best peaches. A perfect peach is a gift all its own. For me, they have been few and far between this season- but then, I could say the same of my nectarines- at least since early season. Summer Beaut and others provided big and beautiful fruit, but the size cost the sugar. At least they were still sweet enough to be quite good. Can’t say the same for peaches, which to my standards, were barely worth eating for the most part. Funny that it is also the most beautiful crop of peaches I’ve ever grown- perfect for people who buy fruit to use like flower bouquets, to be admired in bowls until they begin to rot and are then discarded. Yes, I have a few customers who do this.
That used to be our norm. According to this Climate in Kansas City, Missouri
we get average summer precip of:
June - 4.44"
July - 4.42"
Aug - 3.33"
These last 3 years, we’ve had much more summer precipitation. The grass never goes dormant anymore in the summer. On top of that, when it rains more, it seems like temps are lower, skies are cloudier, evaporation is lower - all of which seem to take a toll on fruit quality flavor. Makes it very difficult to sell the best quality fruit.
I don’t do brix measurements, but I do probably taste more different peaches than anyone else currently on the forum. My own subjective taste observations indicate to me, that if we can get at least 3 weeks of good hot weather with no or minimal rainfall, we can sell a pretty exceptional peach for Midwest standards. These are peaches which very much satisfy my customers with the most discriminating tastes as far as peaches go. You can start to smell the sugar in them with a 3 week deficit and hot sunny weather.
I’m sure it’s not the high brix numbers Fruitnut gets, but can start to gauge or predict comments from customers, when we get a respite from heavy rain for about 3 weeks (i.e. best peaches I ever had; fantastic’ etc.)
This is especially noticeable with early peaches, which is why I’ve found it difficult to grow few early peaches which taste really good (the exception being Spring Snow and to a lesser degree Earlystar). Our May rain average rain totals are 5.39" with lots of cool weather, so the ground never dries.
Wow, I thought you tended to be dry mid-summer on, but your “average” precip is similar to ours. Of course, a lot also depends on relative consistency of precip. If there are large swings year to year there would similarly be large swings in fruit quality. That would be tough on a commercial operation especially. Spoil the customers one year and water balloons would be hard to sell the next.
We seem to be on a dry swing now and I’m about to go out and rake away mulch from my latest peaches and nects. I’m inspired by your suggestion that a 3 week deficit is enough, maybe if I kill enough feeder roots 2 weeks will work.
While I agree with your sentiments there are other considerations for commercial growers. Things like return bloom and health/longevity of the tree. As backyard growers there are things we can ignore that commercial growers can’t. There have been studies done on this for both apples and peaches that I’ve read.
Also in CA the big crop is almonds. You can’t short water on almonds or other nut crops like you might on other stone fruits. I think almond acreage is many fold all the stone fruits put together.
It’s interesting, we do get similar precip in the summer months of June, July, Aug.
Another interesting tidbit, is that from this link, http://www.usclimatedata.com/climate/carmel/new-york/united-states/usny1674 , I noticed that in May, Carmel only averages 4.13", where we average 5.39". This could be at least part of the explanation, why you seem to have better luck growing a very early peach like Rich May (aka FlavorRich) to full flavor.
It generally rains like mad here in May and the temps aren’t hot enough to dry the ground.
I notice summer temps here (both average lows and average highs) are higher than those for Carmel (almost 10 degrees higher in July). The temps and the KS/MO wind probably help speed drying some.
Yes, and for the health of a tree I would tend to assume 1" a week should be more than ample in most environments- that is the number they drill into us in hort school. Especially for a tree that isn’t competing with other trees or weeds. If you have studies that suggest over 2" of water is required every week in the average CA fruit growing region to keep trees healthy and productive, by all means share. It would surprise the hell out of me, and I love surprises.
I planted almond trees in S. CA on a steep slope with nothing but hard sandstone and a little sandy soil. This soil was too dry to support the native live oaks and only the mixed species of native chaparral survived in it. The trees lived through drought years with only 2" of rain the entire season and no irrigation and were still alive after 25 years. Every year they survived no water adequate to penetrate the soil for almost the entire growing season.
Here, many orchards get no supplementary water at all and dry years in good orchard soils are not known to lead to bad crops the following the way overcropping does. Where it becomes a problem is in poor soils for commercial production that are too shallow to hold much water.
Anyway, I’d like to see the data. I don’t trust anyone’s opinions that contradict my own, but I’m happy to change mine if the info is clear.
Here’s a family farm in CA that found smaller, sweeter peaches by reducing water 20-30% nothing scientific. Deficit irrigation: Masumoto Family Farm | Pesticide Action Network
There is plenty of CA studies with early season peaches and deficit irrigation post harvest. Such as https://www.witpress.com/Secure/elibrary/papers/WRM11/WRM11043FU1.pdf
There’s also data out there about water deficit and brix. A small deficit, nothing like fruitgrower, increased brix a point or two. Ashspublications.org
Sorry no time for more but all that came up on the first page of google “California peaches deficit irrigation”.
Interesting, but none of this pertains to the questions I was asking- the effect of deficit irrigation on subsequent crops and tree health beyond indicating no correlation in the second link but was not a subject of the study.
Here’s a good overview of what UC Davis scientist think. Stone Fruit
They mention the pressure chamber technique for monitoring plant water potential that I spoke about earlier. The link doesn’t work but they suggest a threshold that will likely avoid damaging the tree.
Here’s another paper http://ucmanagedrought.ucdavis.edu/PDF/1994b%20CTFA%20RPT.pdf with water deficits of 10+ inches on peaches. Their driest treatment was 50-75% of full ET during the growing season compared to fruitgrowers 12%. Brix was pathetic on all treatments but was increased by water deficit. Be aware I haven’t seen big increases of brix with peach like I have with nectarine.
I’m really amazed that stone fruits tolerate a deficit of 25 inches in such a hot climate as the central valleys of CA. Maybe you don’t remember how hot, sunny, and dry it is every day all day for many months in a row. It never approaches those conditions in NY and even OK isn’t as dry in the worst yr as an average yr in Reedley CA the center of the stone fruit industry. When I was in CA the growers were concerned about internal damage to the fruit when it hit 110F. But I never heard of widespread damage. I do think that low elevations of AZ do go past what peach and nectarine can tolerate. They don’t grow mid summer ripening stone fruit in AZ where it hits 120F. So somewhere between 110 and 120F the limit is reached even with full irrigation.
One inch a week is fine in NY but would be a significant deficit in CA. Even in Texas corn uses an average of 0.33 inches per day. That’s 2.33 inches per week and full irrigation on stone fruit in hot parts of CA. When I was near Amarillo we measured a record for one day crop water use as measured by a weighing lysimeter. Alfalfa used 0.9 inches on one really hot dry windy day.
If you read the research papers carefully you may be unimpressed- what I read was very preliminary and of just 3 seasons, although I’ve not gone through it all. One paper I read was only with post harvest deficits. at the time of the season the trees would require the most water.
I don’t believe deficit irrigation doesn’t raise brix of peaches- it just goes too strongly against my anecdotal experience - even beyond this year of the bland and the beautiful- it also defies the general wisdom of growers around here. A few have remarked to me of an increase in fruit quality (sugar) on dry years.
When I have time I will see how Israeli growers manage peaches. Their research probably goes miles above and beyond U.C. Davis because they never have enough water. They are the ones that developed drip irrigation, as you probably know. I’ve heard of them using a technique where they cut back every branch to the trunk after peach harvest and get their crop next season from what grows back before trees fall into dormancy. That probably reduces the need for water.
Of course I remember how dry it was in CA. I was above the fog and used to grow pot in the chaparral. I could go up to 2 weeks without watering heavily mulched plots without slowing their growth, but they were surrounded by brush protecting them from wind. The soil was almost always very sandy. Believe me, it got very hot at times with frequent dessert conditions in Sept when the Santa Anna winds often blew. However, I flooded the berms of fruit trees and pot plots and didn’t keep track of how much water I was using. After all, I was generally high on my fine home grown in those days.
We all know a deficit helps peaches just like nectarines. My point was it seems easier to get a big increase with nectarines.