Peach1. Q. I have a genetic dwarf peach tree which I purchased at a local nursery two years ago. I have been spraying it according to your recommendations. This included a copper spray immediately prior to leaf fall to prevent bacterial canker infection. Last year, I noticed sap on the branches. You advise that if no holes are present when a peach tree oozes sap, it has bacterial canker. What can I do and where did I go wrong?
A. Your diagnosis of bacterial canker disease would be exactly correct if the symptoms which you are describing were on a regular peach. The genetic dwarfs are different critters. The appearance of gum or sap on the branches, will occur at times when the tree is young. This results from the roots taking more moisture than the top requires. The only way the plant can expel the unused moisture is through its branches. The problem corrects itself as the plant matures and stabilizes its growth. While at times unsightly, this "gumming" does not injure the plant. This is not caused by any insects or disease, but is instead a cultural characteristic of genetic dwarf trees. This may be partially controlled by reducing the moisture given the plant. When possible, avoid planting in heavy soils which hold too much water. This is a good example of why professional horticulturists hesitate the use of the term "always" - - in the plant kingdom, nothing is for sure.
2. Q. What is wrong with my peaches? My trees look ragged with leaves thick in some areas of the canopy yet missing in other areas. I pruned and fertilized.
A. Not only did your tree enjoy a mild winter but the winter or cold weather the area had was interrupted by periods of abnormally warm weather. These periods of warm weather negated much of the accumulated chilling (temperatures below 45 degrees F.) required for normal bloom and foliation to occur. Thus a portion of your poor tree thinks that winter is still with us and some of the same tree knows that spring has sprung. The situation should eventually correct itself. In severe cases though, this lack of foliation can result in tree damage. This is why it is critical to select varieties which have the proper chilling requirement for your area.
Unfortunately this lack-of-adequate-chilling situation also affects fruit set so even though your tree may have bloomed properly don't count your fruit before the harvest--some may yet abort. To determine if your fruit is "sound" cut several, randomly selected, marble-size fruit and examine the soft center which will eventually harden into the seed. If the center is dark or black the ovule is dead and the fruit would have eventually fallen off. If the center is green the fruit will not abort. Q. What causes a jelly-like substance to gather around the base of my peach and plum trees?
The gummy, jelly-like mass you find on the trunk of a peach or plum tree near the soil line might be caused by a worm-like insect that is the larval stage of the either the peach tree borer or the lesser peach tree borer. The peach tree borer attacks the trunk of the tree and the lesser peach tree borer feeds in the scaffolding branches. It is also possible that the deposits oozed out naturally from bark cracking or mechanical injury locations. When gummy sap is mixed with sawdust-like particles it is evidence of borer infestation. If the gummy material is clear, without any signs of sawdust in it, the bark may have cracked for some unrelated reason.
Small mechanical injuries require no treatment. However, if the injury is recent you may want to spray the wound with a fungicide such as captan, which will prevent fungal infection while the tree heals. Take precautions to avoid further mechanical injury. If you have been nicking the tree with the lawn mower, remove the turf from around the trunk and apply a mulch to prevent regrowth.
The insecticide endosulfan, sold as Thiodan or Thiogard, is recommended for peach tree borer sprays. The treatments must be timed properly for adequate control. When applying pesticides follow the label carefully. Immediately after harvest {about mid August) apply the insecticide to the trunks and large limbs to control lesser peach tree borer and peach tree borer. CAUTION: Do not spray any fruit itself with this chemical. Also, do not apply within 21 days of harvest.
An alternative control for the peach tree borer is the use of PDB (paradichlorobenzene) moth crystal. This procedure will not control the lesser peach tree borer. In late summer or the fall, remove grass and weeds from the base of the tree for a distance of 1 foot. Scatter PDB crystals in a band 1 to 2 inches wide, at least 2 inches from the tree trunk. Use ounce for trees under 3 years, 3/4 oz. for trees 3 to 6 years, and 1 and oz. for trees over 6 years old. Cover the tree base and crystals with 4 to 6 shovelfuls of soil packed down with the shovel. Crystals placed against the tree may cause injury. Remove the crystals and the mound of soil from around the trunk prior to regrowth in the spring, to avoid injury to the tree.
Borers feed throughout the winter and spring, so if you think your trees are currently infested, you can try to kill individual borers by inserting a flexible wire into their holes.
3. Q: Why are peaches falling off the tree while they are still green? There are no pests evident.
A: Mother Nature's way of thinning. This is normal for a tree that is loaded with fruit. Often it is a lack of pollination or some other damage to the seed or embryo.
4. Q: How soon can fruit be eaten after spraying?
A: Every product has a pre-harvest interval. Once this time has passed the fruit is totally safe to eat. Check the label of the product to see how long this period is. Generally speaking, most insecticides last only 3 to 5 days at the most.
5. Q: Can the seeds from a neighbors plum tree, which is a nursery- grown hybrid, be used to start a plum tree?
A: Yes, but it will not come back exactly as the same cultivar.
6. Q: When should you plant peach pits to start a new tree?
A: Starting peach trees from seeds is not recommended because the seed will not exactly produce the same variety as the tree the pit came from. However, if you wish to try, they will either need to be stratified artificially or by Mother Nature. Place the seeds in moist paper towels in January and then in a zip-lock plastic bag and place in the refrigerator until April. At this time they will be ready to plant in a pot or in the ground. Or place the seeds in a pot of loose potting soil in early winter and allow Mother Nature to do the job for you.
You will need to keep the pots watered during the winter months if it doesn't rain occassionally. The seeds should sprout naturally in the spring once the weather conditions become favoraable.
7. Q: Are peach pits poisonous?
A: All parts of the peach except the fruit pulp and skin are toxic. These parts contain cyanide-producing substances. Symptoms - difficulty in breathing, coma; may be fatal.
8. Q: What is cause and remedy for sap that is coming from the trunk of a 10 year old apricot tree?
A: It could either be borers or bacterial canker. Spray Dursban in mid-August for borers and Zineb for canker in late October.
9. Q: What causes peaches to rot on the tree?
A: Usually brown rot, a fungal disease, which attacks the fruit just prior to harvest. Spray with an approved fungicide such as benomyl.
10. Q: Is lichen forming on a plum tree harmful?
A: The lichen itself is not harmful, but it usually indicate a decline in vigor by the tree. Try to get the tree actively growing again with extra fertilizer and water. If the tree fails to respond, replace it with a new tree.
11. Q: Birds are starting to work on peaches. Can the peaches be picked before they are ripe? How do you get them to ripen after they are picked?
A: Peaches stop ripening once they are picked. Hence the only answer is to protect the fruit from the birds. Nets are the only sure fire way to prevent this damage.
12. Q: Should peach trees that sprouted from seeds of a now dead tree be kept?
A: If the owner desires a true cultivar, it is recommended trees from seed be avoided as they will not be true to type. However, if the tree makes a satisfactory rootstock it is ok to be used. Such trees are easily "t" - budded to a new variety.
13. Q: What can be used to spray hybrid Bermuda grass in a peach orchard that will get rid of the grass but not hurt the trees.
A: There are several good products which will work. The glyposate products will do an excellent job, however one must be careful to not let the spray contact the trees as it will cause severe damage. Poast and Fusilade will also kill the grass but they will not harm the tree.
14. Q: How should fruit of peach trees be thinned?
A: Thin by hand, one peach every 6 to 8 inches, four to six weeks after bloom. Start with the earlier maturing varieties first.
15. Q: My entire peach crop was destroyed by the many hard freezes we had this winter in Oklahoma. What should I do different in maintaining the trees this year without a peach crop?
A: You are not alone in this disaster of a fruit crop year. Few if any peaches will be harvested in the whole state of Texas this year. Hopefully you have gone to a split fertilizer application system, ie. apply your fertilizer in two or three applications over the growing season. If this is the case then do not apply the next applications. Also if you have not applied any fertilizer, do not apply any. Wait and see what kind of growth the trees make. If they take off and grow vigorously, then there will be no need to fertilize them. They should make 12 to 18 to 24 inches of growth a year. If it looks like the trees are weak in May or June, a small amount of fertilizer could be applied (maybe a 1/4 pound per tree trunk diameter or about 20 lbs per acre; I would just use Nitrogen fertilizer).
Irrigation will not be critical since there is no crop to size, however you need to reduce the stress to the trees in the fruit initiation months of June and July. The more stress in these months the greater the number of doubles the next year. A good weed control program may be all that is needed.
Since you won't have a crop to harvest you will have ample time to do summer pruning. The most important function of summer pruning is to maintain the open center of the tree in order to maintain fruit production all over the tree.
Only minimal sprays should be needed. The most critical thing will be to maintain healthy leaves on the tree. So control leaf feeders as needed and make your borer spray in mid to late August.
16. Q: I have a peach tree that survived Winnipeg Manitoba Canada winter 1995/96, that had the longest, cold spell of 30 days at -30C. The tree was brought from the Detroit area. This spring the trunk, from about 3 inches above ground to 9 inches, developed 2 vertical bark cracks. Checks continued up till 20 inches above ground. I waxed the wounds, wrapped the trunk, and severily pruned all extending branches. Can you recommend some proceedure that will prevent or alleviate problems like this in the future? It is close to a miracle that this tree survived at all.
A: I too am amazed that the tree survived. However, the vertical cracks you are describing are the results of cold damage. You did good by treating the cracks and pruning heavily. In this way there is less demand for water and nutrients and hopefully the tissues will heal and allow the tree to fully recover.
The best way to prevent this type of damage is with mounding. In late fall mound up the soil around the trunk of the tree. Usually you are trying to protect the bud union, so in case the top freezes back you still have the desired variety from which to re-grow the tree. Try to mound the tree 18 to 20 inches high and about 8 to 10 inches around the perimeter; more if you can. Use native soil unless it is extremely heavy and then you may need to bring in some sandy loam. After winter is over the mound needs to be removed or the tree will slowly die. Many use a water hose to knock down this berm.
17. Q: I have two peach trees. There is a gummy-clear secreation coming from the fruit. Several peaches have prematurely dropped from the trees. There are also blistered places on the leaves. The trees are seven years old, grown from seed and this is the first year we've had fruit. What is causing these problems, and what are the solutions?
A: The fruit have been attacked by a stink or leaf footed bug of some type. The sap is oozing from the point where their mouthparts penetrated the fruit. Unfortunately, once you see the symptoms it is too late to do anything. The ones that dropped were probably stung too. Once the fruit is about the size of a quarter, they will usually stay on the tree, but the fruit will be misshapened. One will just need to cut the bad spot away. The only way to prevent such damage is to spray on 7 to 10 day intervals.
The leaf blister could be the result of a bacterial disease called bacterial leaf spot and/or a stress of some sort. The best prevention is to maintain a healthy tree with good fertility, weed control and water management.
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