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Apricot Interest Group
The NAFEX apricot interest group welcomes NAFEX members who are currently
growing or interested in growing apricots. Purpose of the group is to collect
information on the performance of various apricot cultivars, disseminate
information on cultural practices, find and make known sources of finished trees
and rootstocks, act as a means of finding sources of dormant scionwood and
summer budwood, and answer questions about apricots.
To become a member, contact the chairman of the group, Bob Purvis, by mail at
7300 Iden Ave. S., Cottage Grove MN 55016-1935, by telephone at (651)-769-8473
after 5:30 p.m. CST or CDT on weekdays, or any time on weekends, or by e-mail at
rpurvis@nass.usda.gov, and request a membership application. Annual dues to
belong to the group are $10.00 and cover the cost of reproducing material,
postage, phone calls, etc. Payment of dues and submission of an application is
all that is needed to join the gruop. Group members have priority for replies to
questions about apricots and will be sent apricot-related information and
materials periodically by the chairman.
Apricots historically have been a relatively neglected fruit in the U.S. and
Canada. At present most commercial production is concentrated in California,
Washington, and Utah with much smaller amounts in Michigan, Ontario,and British
Columbia. The trees and their blossoms and fruit do best in dry continental
climates where winters are moderately and uniformly cold; springtime dry, warm
and short, and summers characterized by dry, moderately hot conditions. Apricots
do not require high heat levels to ripen properly and be tasty, unlike peaches
and some Japanese plum varieties. Although some apple varieties (for example,
Golden Delicious, McIntosh) can be grown well that do well in one location may
perform poorly in another. Over the past 30 years or so, a better picture has
emerged of the varieties that are best adapted to certain regions of the U.S.
and Canada. Certain varieties are best grown in California (e.g., Patterson,
Castlebrite). Others have been grown successfully in the maritime climates of
the Pacific Northwest (e.g., Puget Gold, Smith). Yet others are well adapted to
cope with the subzero cold and short summers of the Prairie Provinces of Canada,
the Upper Midwest, and the north-central States (e.g., Moongold, Sungold,
Westcot, M. 604, Debbie's Gold, Brookcot). A few can handle the fluctuating
temperatures of a Middle Atlantic states winter (e.g., Jerseycot) and others
have been bred to handle the disease problems and moderately cold winters of
southern Ontario (e.g., the Harrow series of apricots such as Harcot, Harglow,
Hargrand, Harlayne, Harogem, Harval; and Veecot, and Goldcot). A few varieties
have proven themselves high in the Rocky Mountains (e.g., Montrose). Finally,
some locations require low-chill varieties (e.g., Katy, Goldkist).
One of the most important tasks that NAFEX members can do is to identify
which apricot varieties do best in their location and to note which bloom late
relative to the others or bear crops when others are frosted out. The greatest
obstacle to getting apricot trees to crop is getting the blossoms and fruits
through spring frosts. Possibly the second-greatest problem is caused by
fluctuating winter temperatures that may "de-harden" the flower buds and cause
them to begin development prematurely. Certain diseases (e.g., brown rot,
bacterial canker) may require preventive or curative measures in wet climates.
Insect pests to be aware of include plum curculio east of the Mississippi, peach
twig borer in the Pacific Northwest, and earwigs. Vertebrate pests include birds
and (for apricots with edible kernals) squirrels. In view of the effects of
Varroa and trachael mites on wild bee populations, potential apricot growers
should consider borrowing a hive from a local beekeeper, especially considering
that the trees are oftentimes blooming when temperatures are relatively cool for
good honeybee activity.
In terms of cultural practices apricots, like peaches and cherries, do best
in well-drained soils. Unlike peaches, their annual requirements for nitrogen
fertilizer are not great, but like peaches they do best in full sun. In windy
locations, an east-facing location is probably best, especially not far from the
wall of a house. A south-facing location may result in the trees' blooming
earlier than usual. A north slope that does not receive much sun from October
through March is desirable as long as the site is not scoured by cold, drying
north winds, which may desiccate and kill the flower buds, in wintertime. Good
air drainage is essential; do not plant apricots in a "frost pocket." A
west-facing location is undesirable because the trees will be exposed to the
prevailing winds and not to the warming rays of the early-morning sun. Tree
trunks should be painted with a 1:3 mixture of white latex paint and water to
prevent winter sunscald damage and premature warming-up of the trunks.
Concerning growth and development, apricot trees should be planted early in
the spring. Except in warm climates, avoid fall planting because of the risk of
subsequent winter-injury. The shoot growth produced in a given year is capable
of bearing fruits the following year. Shoot sections form fruit spurs in year 3
(that is, two seasons after the shoot is grown), and the spurs can remain
productive for up to 4 years. Removal of older branches by pruning is important
to form new growth, and the tree should be pruned in such a way as to allow good
penetration of sunlight throughout the tree and to avoid narrow crotches.
Apricots in full bloom can withstand temperatures of 21 degrees and still set a
crop. After the "shuck" (spent flower parts) fall off the young fruits, they
cannot tolerate temperatures much below 28 degrees F.
Detailed pruning of long shoots (shortening them) is best done after you know
the size of the crop that has been set. Thin the fruits when they are about the
size of a dime or quarter, to about one every 4", to maximize fruit size. Trees
that are severely overcropped will produce small fruit and be vulnerable to cold
injury the following winter; furthermore, they may go into bearing only every
other year.
Apricots are best propagated on Manchurian apricot seedling in cold climates
or on common apricot seedling in warm. Bench grafting needs to be done with
dormant scionwood and rootstocks. Best results come from putting freshly grafted
rootstocks into a box held at 80 to 85F to promote rapid callusing although
fair-to-good results can be obtained keeping them at 65 to 70F. As with other
stone fruits, propagation by budding in early to mid August is best because the
warm temperatures occurring then encourage rapid uniting of the buds with the
rootstocks. Apricots propagated on peach rootstocks are oftentimes productive
and vigorous but may be shorter-lived or more vulnerable to winter injury than
those propagated on apricot. Plum rootstocks such as St. Julian A are sometimes
used on heavier soils or to impart a degree of dwarfing, but apricot on plum can
sometimes suffer from delayed incompatibility at the graft union. Sand cherry
(Prunus besseyi) has sometimes been used as a dwarfing rootstock, but even now
there are no widely available, dwarfing rootstocks for apricot. Support for the
tree may be a good idea if it is grown on a plum rootstock.
Apricot trees, once established, are somewhat drought-tolerant. Thanks to
losses of crop some years and bearing fruits relatively early in the growing
season, the branches and trunks of apricots can become quite large over time.
Even in years when late frosts take the crop, the trees are gorgeous in spring
with white or pink blossoms, and ornamental in summer with their furrowed bark
and heart-shaped, glossy leaves, red when new and dark green when mature. Given
good care and weather, a 1-year-old tree purchased bare-root from a nursery can
bear a few fruits in its second season at your location but will bear a much
better crop its third year in the ground. Flower buds for the following year
begin to form between late July and early September, so it is important to
supply a tree with adequate water during this period of time.
Tree-ripe, high quality apricots are rarely seen at the supermarket and not
often at farmers' markets. Apricots are very high in potassium, vitamin A,
niacin, and iron. In the kitchen, their generally freestone quality makes them
easy to prepare for canning, drying, or use in baked goods. For canning, use
fruits that are firm; use fully ripe fruits for fresh eating or drying. Keep
these virtues in mind when considering whether or not you should try and plant a
tree, or stay up late at night sprinkling an apricot tree in bloom when
temperatures dip below freezing.
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