Subject: Irrigating a home orchard

From: [email-masked] (Mark Evangelisto)
Date: Thu, 21 Mar 1996 23:43:07 GMT

Hi,

I planning on starting a small grove of fruit trees this spring (if it *ever*
get here :-) and was wondering if anyone out there could provide any words
of wisdom as to how to efficiently irrgate the trees I will be putting in.
This year, I'll be planting a total of 16 trees of varying types, mostly
semi-dwarfs. I'm planning on setting them out in 2 rows of 8 trees, spaced
about 10-15 ft apart, depending on the type of tree.

Thanks,
Mark

--
-- 
Mark Evangelisto                 e-mail: [email-masked]
Cadence Design Systems           v-mail: (508) 446-6269
270 Billerica Road                 
Chelmsford, Mass. 01824-4140       

		This space for rent.....

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From: "M. Counides" <[email-masked]>
Date: 22 Mar 1996 14:14:01 -0700

There are commercial systems on the market with emitters for every tree.  
That is what is used in  orchards around here.  I use short lengths of 
hose joined together.  I have noticed how nicely plants grow in places 
where hoses are connected and leak. I have merely arrainged for a 
connection and leak at every tree.  My trees are strung out in single 
lines around my garden and on the edge of the yard mostly.

Naomi Counides
Associated Beefalo of Idaho

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From: "M. Counides" <[email-masked]>
Date: 22 Mar 1996 14:15:01 -0700

Naomi Counides

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From: [email-masked] (Greg Wallraven)
Date: Sat, 23 Mar 1996 13:50:02 GMT

>		This space for rent.....
Mark,

Last year I installed a drip and sprinkler irrigation system which
covers about 30 trees and shrubs  and 2 flower beds.  The system I
purchased is manufactured by a company called Moisture Master,
although I am sure there are others out there just as good.

The installation was unbelieveably easy, requiring no tools and very
little time.  I had the whole thing in in a couple of hours.  The drip
emitters are flow regulated to allow from 1 to 4 gallons of water per
hour, depending on which ones you select.  I put the whole system on
one hose with a timer, and have been absolutely thrilled with the
results.

You might look for something like this.

Good luck!

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From: "Curt R. Rom, Associate Professor, Pomology" <[email-masked]>
Date: 25 Mar 1996 02:23:02 GMT

Generally, we have observed that fruit trees will have enhanced 
performance and increased longevity with supplemental irrigation. 

Your question can be further broken into two parts.  The first 
question may be, how much irrigation is necessary for a fruit tree.  
The second question may be, what is the best method to irrigate. 

How much water do fruit trees need.  Typically, our research and the work 
of others indicates that fruit trees have changing water loss during thes 
eason.  Early during the season, fruit trees may lose about 75-85% of pan 
evaporation from bloom until the canopy forms.  However, at mid-season 
(beginning in June or July) with a full canopy and crop, a mature apple 
tree may lose 110 to 125% of pan evaporation from both evaporation from 
soil and from evapotranspiration from the tree.  When we use our 
measurements of foliar evapotranspiration and estimate total tree water 
loss, a semi-dwarf tree may lose 30-50 gals of water per day; a dwarf 
tree may lose 10-20 gals of water per day in mid summer.  Research 
reports indicate that even small soil water stress can start to cause 
reductions in developing leaf size, reduce fruit cell formation (stress 
in the post-bloom period) or reduced fruit cell enlargement (during the 
growing season).  Thus, preventing soil water stress is the critical 
issue.  

One could estimate that an "average" clay loam soil can hold 2 to 4 
inches of water per foot of soil profile.  Knowing that the tree roots, 
primarily the feeding roots, are confined to the top 12-24 inches of 
soil, then there is potentially 4-8 inches of water available.  However, 
when an estimated 30-50% of the soil water is removed from the soil 
(either by gravity, evaporation or tree use), there is suffiencent soil 
water tension to cause negative growth effects.  Thus, the tree has 
approximatey 2-6 inches of water available for it use without much 
stress.  Knowing that average mid-summer evaporation in most warm, 
temperate areas is 1/4 to 1/3 inch per day, then the soil may have a 
usable supply of water for 6 to 20 days (we estimate 5-10 days).  Thus, 
every 5-10 days we think we need to replace the water in the soil to keep 
it at an "optimum" level.  In our orchards, we typically never exceed 7 
days between irrigation cycles (for sprinkle irrigation). This is 
adjusted whenever we get 3/4 inch or more of precipitation.  We have 
found that less than 3/4" is "useless" as far as the tree is concerned.  
We begin irrigation as soon as we calculate deficits in the soil (using 
either the mathmatical models [similar to what was described above] or 
using soil tensiometers.  Using soil tensiometers or "irrometers" [TM] we 
irrigate whenever the morning soil water tension is -40 cbars. 

In a study we did, where we replace 110% of evapotranspriation loss using 
whole tree lysimeters under 'Delicious' and 'Golden Delicious' trees on 
M.26 rootstock, we found that at 4 years of age, trees lost approximately 
10 gallons of water per day.  When the water was replaced daily as 
compared to weekly, the trees with daily water replacement had almost 
twice as much dry matter and wood production as the trees watered only 
weekly (probably droughted then flooded then droughted then flooded, 
etc.).  In the first cropping year (year 4) yield was similar to total 
growth with almost twice as much yield on daily irrigated trees. 

How to irrigate?  We do not think that the tree cares how it gets its 
water but, the method has tremendous management consequence.  We have 
observed, but not tested, differences in tree growth between 
microsprinklers and trickle/drip irrigation emitters.  Others have 
reported differences between irrigation systems for growth and cropping; 
there is even a report that shows that with sprinkler irrigation, the 
sauce made from processed apples on sprinkler irrigated trees was 
"runnier" than that of apples from trickle irrigated trees. 

With trickle irrigation, it should be thought of as "replacement 
irrigation" and should run every day or every other day.  The emitteres 
can not put out enought water and create enough of a soil "wet zone" to 
overcome dry soils -- once you get behind, it is hard to catch up.  In 
our orchards, we trickle irrigate every other day for about 5 hours 
putting out 10-20 gals per tree per day (2 - 3 emitters per tree in the 
drip zone at 1/2 to 1 gal/hr at 20psi).  We now like micr sprinklers with 
a 4-6 foot cast.  These put out 2-4 gals/hr and will cover 2 trees.  We 
observe somewhat better growth (completely horticulturally subjective); 
it is also creating a larger "wet zone" for the trees which in our 
climate with good spring rains and occassional summer rains is important 
(a widely dispersed tree root zone); it works better for supplemental 
irrigation and it is easier to "catch up" if the soil gets too dry.  We 
tend not to use high volume impact sprinklers because of the cost of both 
equipment and water (also a dryer tree row middle -- the drive row) will 
mean less mowing).  We have not had good success with subterranean "leaky 
pipe"; although our experience with the pipe ontop of the ground has been 
better (1] you can't tell of it is working, 2] weed and tree roots tended 
to penetrate the pipe and plug it, 3] its performance is very much 
determined by soil type). 

In my home orchard I used surface leaky pipe for a while but have now 
gone to undertree microsprinklers.  I have them on a timer to run 2 hours 
per day, every other day (unless >3/4" rain).  I run them at the middle 
of the afternoon because there is literature to suggest that undertree 
irrigation may cool an orchard 3-10 degree F -- even though I lose some 
water in this process.  I purchased all of the equipment, including an 
inline fertilizer injector, pressure regulator, back-flow preventer, 
sprinklers, etc., from a local hardware store/garden center.

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From: [email-masked] (Matthew Shugart)
Date: Tue, 26 Mar 1996 09:00:52 -0800

I note that Mr. Evangelisto posted a note indicating that he is planning
on planting mostly sem-dwarf fruit trees 10-15 feet apart.  Now I am no
expert, just a (successful) backyard fruit grower who consumes a lot of
information provided by other growers and gardening societies, but the
10-15 foot spacing recommendation in many old books about how to grow
fruit is really obsolete for home growers.  If you are a commercial grower
you need to allow a lot of space.  But there is a newer approach called
"Backyard Orchard Culture" that is promoted by Dave Wilson Nursery in
California, which is a major supplier of fruit trees to nurseries and a
licenced grower for Zaiger Genetics (the good folks who have brought us so
many new varieities and hybrids, including Pluots).  

They recommend that home growers select a size that they want the tree to
get to, say 8-10 feet and, with summer pruning, keep it there.  That way,
planting can be more dense, even without dwarfing rootstocks (some of
which don't really dwarf that much anyway for trees like peaches and
apricots, at least in certain soils).

You can also plant three or four trees of similar growth habit in one hole
(actually, about 18 inches apart) and angle them outwards somewhat. 
You'll need to prune a bit to keep the center open, but then you will
probably want to do that on a single tree anyway.

They even recommend planting hedgerows of fruit trees, 30 inches (yes, 30
inches) apart.  I really can't fathom that one, but they do recommend it.

And of course there is espalier as a nice attractive (but not exactly low
maintenance) way of getting a lot of trees into a small space.

I was very happy to see so many responses to this original query.  In
general, there seems to be too little activity on this newsgroup, but it
was nice to see 5 replies to this one message in such a short time.  I
would be very curious to know how others with more experience than I feel
about the high-density planting and size control techniques that I refer
to here.  I am sure there are those who consider them an abomination.  But
they make sense for those of us with limited space and no need for lugs of
fruit that all ripens at once.  With these techniques you can have several
varieties chosen for successive ripening on manageable-sized trees.

By the way, speaking of pluots, anybody out there growing them?

Good growing to all!

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From: [email-masked] (Stephen M Gomez)
Date: Thu, 28 Mar 1996 17:24:52 -0800

In article <[email-masked]>, "Curt R. Rom, Associate
Professor, Pomology" <[email-masked]> wrote:

> We have not had good success with subterranean "leaky 

Here in the desert of southern California, it seems that the opposite is true.
In our small grove of orange, lemon, and grapefruit trees (5 orange, 5
lemon, and 3 grapefruit; aprox. 12-15' apart, in three rows) we have found
that leaky pipes under the ground are much better that sprinklers,
especially in the summer and early fall.

Our pipes are aranged made w/ 3" PVC connected w/ a three way elbow
joint.  the arms  about 1' under ground are about 4' long w/ 1/2" holes
about every 4" along the bottom (dont want water to stand and get
mosquitos, the county doesn't like that either).  the third pipe extends
about 18" above the surface and has a cap.  the cap is on to prevent the
water in the ground from evaporating back out.  

In consideration of the points above:

1) we did a "test" by placing this apparatus on only one row of trees at
about the limit of lower branches.  We noticed a HUGE difference in the
"happiness" (I use it as a scientific term, but someone needs to come up
w/ a standardized happiness scale.)  Sprinklers were run for 2 hours every
night, while the pipes were filled every 3 to 4 days.  Trees grown w/
sprinklers did the same as those w/ pipes during the winter and spring (we
water only when it hasn't rained for more that 7 days, which it is doing
as I write), but during the summer (which is hot and dry) the trees that
were watered w/ sprinklers were always drought stressed and had curled up
yellow/green leaves (probably due to the increased xanthophyll content and
decreased chlorophyll b in the antenna for photoprotection) ,the pipe
watered trees were bushy and green and happy, except for the aphids that
seemed to prefer these trees to the sprinkler irrigated ones. (BTW does
anyone know of a "nontoxic" aphidicide other than soap?)

2) There tends to be fewer weeds under the pipe trees, I think due to the
water being already under the ground and no water on top for the seeds to
sprout.  Tree roots eventually plug up the holes and dig up the pipes
every 2 years and move them to the other side of the tree.

3) Our soil is very sandy, so the water doesn't stand in the pipes for
very long.

I have no idea if the pipes would be a problem in places w/ winter.  I'd
check to see if the air in the ground could freeze the roots.  But what do
I know about cold.  Currently we water all our trees w/ the pipes.

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From: [email-masked] (Guest)
Date: 2 Apr 1996 03:35:21 GMT

In article <[email-masked]>, [email-masked] (Greg Wallraven) wrote:

Drip is definitely the way to go. Not only is it inexpensinve, but you can
customize yoursystem to deliver the correct amount of water to each plant
by changing the emitters.

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From: [email-masked]
Date: 3 Apr 1996 04:39:51 GMT

[email-masked] (Stephen M Gomez) wrote a whole lot about a 
completely different topic, but asked in an aside:
>(BTW does anyone know of a "nontoxic" aphidicide other than soap?)

Don't know how they react in your climate [it's hot, from his earlier 
post], but the best thing other than Safer Soap that I've found is 
ladybugs.  :D

Try to get the "Stay-at-Home" ladybugs, or if you can find them, splurge 
on ladybug larvae!  They're the *real* aphid killers!

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From: [email-masked]
Date: Wed, 03 Apr 1996 22:18:16 -0800

> [email-masked] (Stephen M Gomez) wrote: 

A friend had excellent results repelling aphids with a really stinky hot
pepper and garlic spray.