1. Q: Three weeks ago I pruned my young apple tree, and now it is time to fertilize it. I need to know just exactly how to do that.
A: As a general rule of thumb, nitrogen is the main element which makes plants grow. They respond best to small frequent amounts of fertilizer. We like to apply 4 applications of fertilizer per growing season to young trees, usually March, April, May and June. In year one we usually only apply 1 cup or 1\2 pound of ammonium sulfate. In year two we use 1 cup of ammonium sulfate at the first of the months listed. Be sure to keep the fertilizer 12 inches from the trunk of the tree and only continue to apply fertilizer if the tree continues to grow. In year three, use 2 cups or 1 pound in each of the months listed. In year 4 use tree trunk diameter as your guide, or 1 pound of fertilizer per inch of trunk diameter. The total can be split into at least 2 or 3 applications, ie. March, April and May.
Keep in mind that apples require cross pollination so you will need another tree of a different type in order to set fruit. You can put flowers of a different apple tree in a can of water and hang them in your tree if you only have room for one tree.
2. Q: Do different types of apples have the same number of seeds? Why? We cut a Golden Delicious, Red Delicious, and a California Granny Smith apple. All three had a different number but I don't understand why. Could you please help me out?
A: If you were to cut an apple in half, cross-sectionally, ie. not through the stem end, you would find that an apple has 5 compartments or carpels. Each of these carpels should contain a seed in order for the apple to be full sized and well shaped as the seeds produce hormones which allow the fruit to develop. Fruit which lack seed often abort from the tree in times of stress. Varieties can have more than one seed in each carpel depending on the health and vigor of the tree; the more healthy a tree the more potential seed the fruit can have per carpel. This is probably why the different varieties had different numbers of seeds. Trees with too many fruit and seeds can exhaust the stored food of the tree and thus fail to set a crop the next year.
3. Q: Last month my dwarf green apple tree, withered and died in a matter of about 10 days. The tree was 5 or 6 years old and just covered in beautiful green apples, I was watering the tree every week or 2, until we started to get rain finally. I have a second tree (red apple dwarf) same age , etc.. only 10 feet away and it is fine. There have been no chemicals in my yard. And I have no idea what happened to it. Some of the leaves turned yellow, others brown, some just withered. I'd also like to know if I get another, should I plant it elsewhere?
A: More than likely your tree died from cotton root rot, a native soil borne fungus. It slowly kills the roots and then suddenly the plant appears to die overnight. It is devasting to apples and grapes. It travels through the soil on the roots of the apple tree. So you may want to dig a trench about 1 to 2 feet deep between the two trees to cut the roots and minimize the chance of the fungus spreading to the other tree. Place a piece of plastic in the trench to keep the roots from the healthy tree from growing into the area where this tree died.
Plant a new tree in another spot. More than likely the tree would die if you plant it in the same spot. There is no good treatment for this fungus except avoidance and resistant plants. Persimmons are probably resistant to this fungus.
You may have to go to planting trees in containers to avoid this disease. You would need to get trees budded on M - 7 rootstock if you are going to plant in containers.
4. Q: I am south of Houston 35 miles in Brazoria county. I would like to know a couple of peach and apple varities that are low chill hours enough to do well here.
A: The best low chill apple varieties for your area are Anna and Dorsett Golden. You will need to plant both as apples require cross pollination in order to set fruit. Get them budded onto M-9 rootstock or MM-111. The M-9 is a dwarf tree and will require trellis support; MM-111 is a free standing tree, but will take longer to come into production. Apples are easily propagated by a "t" bud. However, trees grafted onto seedling trees are slow to come into production.
Three good low chill peach varieties for your area include: Florida Crest, Florida King, and TexStar.
5. Q: What dormant sprays can I use to control peach leaf curl and severe annual aphid infestation of apple trees? I'd like to use sprays which are allowable under organic growing regulations in California (CCOF).
A: A fungicide spray, usually Kocide (copper hydroxide) applied anytime between leaf fall and bud break in the spring will control peach leaf curl. Other fungicides can be used, but Kocide will do a good job. Cool, damp weather in the spring increaes the chance of this problem. So you may or may not have a problem next spring.
Since aphids overwinter as adults, you can try using a dormant oil spray next spring before budbreak. This may reduce numbers although there are no guarantees. Aphids can blow in and migrate for long distances so they are usually an annual problem.
6. Q: Can you give me the preferred soil test results for apples, pears and tart cherries? For example, pH, how much Mg, Mn, N, P, K, Ca organic matter, etc.
A: The preferred pH for most fruit crops is 6.5 - 7.0. Most nutrients are readily available at this level. Nitrogen is very low in Texas soils so it is rare to have any come back on the soil test report. Ideally there would be about 50 ppm nitrogen in the soil. P should be about 10 - 20 ppm. K, 80 to 120 ppm. Ca 500 to 1000; we have very high levels of Ca due to the high pH nature of our soils. Mg, 80 to 150 ppm. And 5 to 10 ppm Mn.
In most cases the only element we need to apply in Texas is nitrogen. In fact if our soil pH is above 7.0 we only recommend nitrogen fertilizer. If the soil pH is below 7.0, then one can apply a complete fertlizer such as 15 - 5 - 10. Use one pound of fertilizer per inch of trunk diameter and apply this material to dripline of the tree. Either incorporate lightly or water in after application for best results.
7. Q: I live in Montana and have a very old McIntosh apple tree. I have planted the seeds from its apples and have obtained seedlings, but they won't bear for several years yet. I have a few questions:
(1) Is there any way to tell if the tree was grafted? I see no obvious markings.
(2) If it is grafted, will my seedlings revert to the rootstock?
(3) Where can I find true trees(non-grafted) so that I can save the seeds and grow trees that will be true to the parent?
(4) Are there any varieties of nut trees that will grow in my area?
A: More than likely if you have a McIntosh apple tree, you have a grafted or budded tree. Since fruit trees do not come true from seed, they either have to be budded or rooted. It is difficult at best to root woody plants such as apple and the like. They are often rooted in stool beds, but this is also an involved process.
If there is no change in bark color or texture then there is really no way of knowing if they were grafted or not. Also the bud union may have been placed below ground at planting, which of course is not recommeded.
The seedlings will be whatever their genetic makeup dictates they be. If there are no other apples around, then the seedlings may be selfed McIntosh trees which may or may not be good. However, apples normally require cross pollination so it may be that bees brought pollen in from another tree. So you may or may not have a good apple.
The adaptability of nut trees will be dictated by the minimum temperatures in your area. The critical temperature for some nut trees is -20 degrees F. At lower temperatures most of the Persian walnuts, European filberts, some heart-nuts and Japanese chestnuts may experience serious injury. A lot of folks use peaches as their indicator plants; ie if peaches produce good crops nearly every year, it is likely that most of the northern nut clones will be winter hardy.
8. Q: How is the best way to tell when apples and pears are ripe?
A: Harvest time varies with individual tastes and locality. One may consider a fruit ripe while another individual believes it is immature. However, fruit picked too soon does not store well and does not develop full flavor.
Probably the most reliable index is the number of days after bloom: Red Delicious 135 - 155 days from full bloom to harvest whereas Granny Smith takes 170 - 180 days from full bloom to harvest.
Other factors to consider include seed maturity; in most cases the seed of mature apples will be turning black. Also the background color changes from green to yellow. Generally speaking, as red apples reach picking maturity the green peel becomes slightly yellowish. Green or yellow varieties change from green to creamy white or yellowish as they reach maturity.
The flesh of immature apples usually exhibits a greenish tinge. When ready to harvest most varieties become a creamy white or yellow.
Lastly is fruit drop. Normally when natural fruit drop begins, harvest should be well underway. Some varieties may not taste fully ripe when they drop. However, apples continue to ripen off the tree. So store them for several days at room temperature in a cool part of the house until there is sufficient conversion of starches to sugar to give them a good ripe taste.
When picking apples, it is important to avoid injury to the fruit. Remove the apple from the spur by pulling upward and outward while rotating the fruit slightly. On some of the thin, long-stemmed varieties such as Golden Delicious, it is sometimes necessary to firmly place the index finger at the point of attachment on the stem and spur to prevent the spur from breaking. Apples picked with the stem attached to the fruit keep longer.
The Oriental hybrid and European pears grown in Texas do not ripen well on the tree. They are ready to harvest when they change from hard to firm (firmness similar to a softball). Harvest maturity is usually indicated by a slight change from green to yellow.
Mature fruit will begin to drop even though still hard, if harvest is delayed. Most pear varieties in Texas reach harvest maturity in August and September. They should be picked and ripened off the tree. Pears remaining on the tree too long ripen poorly and have poorer texture and flavor.
Ripen pears at room temperature in a well ventilated area. They will ripen in 1 to 2 weeks. Refrigerate the fruit after ripening until consumed or processed. For longer storage life, refrigerate unripe pears as near 32 degrees F as possible and then ripen as desired.
| PLANTanswers Home | Aggie Horticulture |