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The Apricot Challenge.

By Richard Ashton
Freelance Writer

Apricots have been a problem fruit to grow in Texas for many years. Although the fruit can be grown in most areas of Texas the trees do not produce every year and may only produce a crop of fruit in 2 out of every 5 years. That is not a good situation for most people interested in growing the fruit. It is disappointing to have the trees bloom and then see the blooms or young fruit destroyed by one of our late freezes. The main reason for inconsistent cropping is that apricots are normally one of the first fruit trees to bloom in the spring.

There are things you can do to make apricots bear more consistently. The first is variety selection. By selecting a variety that blooms later than most apricots or has a long blooming season, as well as the varieties that have hardy blooms, you can get past many of our late frost problems.

To determine variety selection we need to examine the origin of our domestic apricots. Apricots originated in an area from central Asia to Manchuria. The central Asian apricot group is the ancestor of our present European/American apricot varieties. There is great diversity in the central Asian group but the European/American group of apricot varieties has very little genetic diversity. In other words, our present American apricot varieties are very much alike in their characteristics: large, good shipping fruit of fair taste with an early bloom time. The central Asian apricots are small, very sweet tasting fruit on trees that bloom very late (when compared to American apricots). This late blooming characteristic is what we are interested in when breeding apricots for the future.

An apricot breeding program in New Jersey used a central Asian apricot variety called 'zard' crossed with a French variety to develop an apricot variety called 'jerseycot' that blooms nearly two weeks later than most American apricot varieties. The 'jerseycot' variety is not available commercially but budwood can be obtained for grafting.

The USDA sent a fruit exploration team into northern Pakistan to the Hunza valley to procure some of the famous apricot varieties growing there. The Hunza people eat as their main diet: dried apricots, apricot seed oil, roasted apricot kernels and millet. It must be mentioned that our American apricots have kernels that are poisonous, whereas the Hunza apricot kernels are sweet and edible when roasted. The people in the Hunza valley live longer than most people in the world, and cancer is nearly unknown. There must be something about their food that contributes to their health.

With seed and budwood in hand, the team brought the Hunza varieties back to the USDA research station in California. Now they are crossing the Hunza apricots with our American apricots with the hope for later blooming apricots with larger, sweeter, good shipping fruit. Dr. Craig Ledbetter is heading up this effort with the USDA. He says that the Hunza apricots hold promise but the fact that the fruits are small makes them unsuitable for commercial production unless the cross breeding program is able to develop larger fruit.

The Canadian agricultural research station at Harrow, Ontario, Canada developed several later blooming apricot varieties, with the best all-around being 'harglow.' It has good sized fruit and it truly blooms later than most apricots. It is available through mail-order from several nurseries.

The South Haven Experiment station in Michigan some years ago developed an apricot variety that, although not a very late blooming apricot, has blooms that can stand more frost than ordinary apricots. It is called 'chinese' and should be considered a good variety for all areas. It has clingstone fruit which means that it is not a good commercial prospect, but for the home grower it can be a good one.

The research station at Prosser, Washington, developed a variety called 'tomcot' that although it does not bloom late, it blooms over nearly three weeks which means that if the first blooms are bitten by a late frost the later blooms have a good chance of producing fruit. The fruit matures early and is of good size and flavor. It is considered a commercial apricot because of its large size and good shipping qualities.

Varieties developed from unknown parents (seedlings) in our state are another good source of later blooming or bloom hardy apricot varieties. Two varieties that fall into this category are 'tisdale,' sold by Womack Nursery in De Leon, Texas, and 'bryan,' a variety sold by several Texas nurseries. Both have more consistent production records in Texas than most apricot varieties available. They do bloom a little later and are considered mid-season bloomers.

The second thing that will help prevent frost damage is environmental in nature. Years ago, people might drive by a fruit orchard and see fruit trees with their trunks painted white and think that sure makes a nice looking orchard. Well, the painting of the trunks with white latex paint diluted 50-50 with water is more than a nice looking feature to an orchard. By using regular white latex (not oil based paint) and mixing it with an equal amount of water and then applying it using a painting glove (sold at many paint stores) or sprayer you can do two things: 1. keep the trees cooler, resulting in a later bloom time for your apricots, and 2. help reduce insect problems from insects that borrow into the bark or crawl up the trunk from the ground.

Keeping the trees cooler than normal will help delay any apricot's bloom time. You can put down a layer of compost or mulch under the trees and keep the soil cooler as another method of delaying bloom. Just do not put it directly up against the trunk of the tree.

Planting trees on a slope so that frost can "drain away" downhill also helps produce apricot crops in areas prone to late frost. In commercial orchards sometimes sprinklers are used to spray trees with water when a frost is expected, but for the home grower that is usually not an option.

Something must be said here about chilling hours for apricots (that's the amount of hours in winter below 45F). Many of the apricot varieties need about 700 hours of winter chilling, to produce a full bloom in the spring. At least 2/3 of Texas has 700 hours of chilling so most of us do not have to worry too much about this. However, for the people in the southern part of the state there are low-chilling varieties that should be considered. The Gold Kist variety has a very low chilling requirement of 300 hours and can be planted in the southern part of the state with a good chance for production. 'Katy,' a California variety with a 400 hour chilling requirement, is also a good candidate for the same area.

Apricot culture is not too much different from most stone fruit (peaches, plums, cherries etc.) A good deep loam type soil is best, but most fertile soils will suffice. A dry climate is best if the trees can be watered in periods with low rainfall. Apricots are the most drought tolerant of all the stone fruit, especially on apricot rootstocks (most apricots are grafted on peach rootstocks). Apricot trees are very long-lived trees, much longer than peaches. There are apricot trees in Texas still producing fruit at 40 to 50 years of age.

Apricots like a sunny location along with pruning that allows the sun to penetrate into the tree. They do not require as much pruning as peaches but the open center type of pruning is best for apricots because the more sun the fruits get the nicer they will appear. Prune any limbs that overlap and remove any limbs that start too close to the ground. You must be careful not to prune too much since apricots bear fruit on fruit spurs that are 2 years old or older. So if you prune too much you will not have a good crop the next year.

Pests can be a problem with apricots but not as much as with many other stone fruit. The plum curculio is a major pest that can cause much ruined fruit. It can be held in check by spraying at petal fall (the time when the bloom petals start to fall off) along with one to two additional sprays at 10 days to 2 week intervals. Check with your county agent or local garden center about what chemicals to use. There are other insects that cause problems but the plum curculio is the worst insect problem in our state.

Watch for birds pecking the fruit. If you get one of the earlier ripening varieties the chances of bird damage will be less because the early fruit just do not get noticed as much as fruit maturing later in the season. You can use bird netting, but usually you have a large enough crop that letting the birds have a few is not a problem.

One thing that has just recently been discovered is that apricots need a good supply of zinc. Dr. Ledbetter of the USDA believes that a fall application of zinc causes the flower buds to develop better for blooming the next spring. You can use zinc sulfate applied and worked into the soil, and there are foliar sprays that contain zinc which can be applied. You may be aware that pecans have this same zinc problem. Lack of trace elements in the soil can be the source of problems with trees that fail to bloom and fruit. A soil test is best if you have trees that are old enough to set fruit but fail to bloom. Any county agent in Texas can supply you with materials for a soil test through the Texas A&M extension service at a very small charge. I have been asked by a number of people why their apricots have failed to bloom and set fruit. The lack of some of the trace elements — especially zinc — may be the answer.

Richard Ashton is the author of several books on fruit growing. The Incredible Pomegranate - Plant and Fruit, Jujube - The Chinese Date and his soon to be published book Sweet Cherries for Southern Orchards are available from Third Millennium Publishing at www.3mpub.com/ashton or they can be purchased through the Texas Gardener bookstore.

 

SOURCES
I have mentioned several apricot varieties that seem to have better chances of producing reliable crops in Texas. Here are a few places to get them:

Womack Nursery in De Leon, Texas, (254) 893-6497 has the Tisdale variety, which is a good all-around variety. They also sell Peggy, a variety that I would not recommend for all of Texas but is good for the North Texas area. These are both Texas developed seedling varieties.

The Tomcot variety can be purchased from Van Well Nursery in Wenatchee, Washington, www.vanwell.net or (509) 886-8189, which ships trees bareroot in the early spring. They have started a program where you can purchase just one tree (although they are a wholesale nursery). It is advisable to plant another variety with the Tomcot variety for better production, although it will produce if planted alone.

Bay Laurel Nursery of Atascadero, California, sells several of the varieties that I have mentioned by mail order, including the low-chill varieties. They are on the Web at www.baylaurelnursery.com or by phone at (805) 466-3406.

You can get scionwood for grafting of the Jerseycot variety by contacting the USDA-ARS and asking for Accession DPRU1051 — 'jerseycot.' They are at: www.ars.usda.gov/Main/docs.htm?docid=13394 on the Internet or you can call them at (530) 752-7009. The scionwood is free but must be ordered before December 1 of each year.
 



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