Time is ripe for problems with peaches
This is the problem time of year for peaches.
n Limb breakage. If there’s too much fruit on a single limb, the weight can cause the limb to separate from the trunk. We get limb breakage at the University of Nevada Cooperative Extension Master Gardener Orchard in North Las Vegas if we do not remove enough fruit from the limb when the fruit is small or if the limb has a poor attachment to the trunk.
Peaches should be thinned when they are small so that the young fruit is about 4 to 6 inches apart. Also light, summer pruning will help to keep fruit loads more manageable. During April and May excessively long branches on peaches and nectarines are pruned back so they are no longer than about 18 inches. This helps to distribute the crop load for the next year, which is born on the wood that is produced this year.
n Wormy peaches. Peach twig borer in the adult stage is a brown moth about ½ inch long. After eggs are laid by the adult moths, small worms or larva enter soft fruit, usually near the stem end. When they enter near the stem end, they leave behind some brown excrement that looks a little bit like wet, dark-brown wood grindings.
But earlier in the season when there is no fruit, they attack something else that is soft and tender – new growing shoots. They tunnel into the soft ends of the shoot where they cause the newly grown tip to die back. Later in the season, when there is soft fruit, they attack the fruit instead.
It is important to get these insects under control very early in the season, around April and May, with sprays like Bt or spinosad. There can be several generations, one after another, and their numbers multiply at very high rates.
These little guys also will attack almonds. They get into the outer husk where it is essentially just like the fruit of a peach. They also can tunnel inside the nut and cause damage there as well.
Q: I have eight California seedless grape vines that are 3 years old and this year they are sprouting a lot of grapes. My question is, how do you keep the birds from eating up the grapes? I have a fig tree that I sprayed with a bug killer and that kept the birds from eating the figs. What is good to put on the grapes so I can eat them instead of the birds?
A: We don’t spray anything on our grapes to keep birds off of them. Unlike some other fruit that we can harvest a bit early and allow to mature off of the tree, you can’t do this with grapes or figs. They must mature completely while still on the vine or tree.
The only real safe alternative you have is to use bird netting to exclude the birds from the plant and fruit. Bird netting must be securely fastened or tied to the ground or to the trunk. You must not leave any spaces for birds to go under it or force their way through it or it will not work.
I am not sure that I would be very comfortable spraying fruits with an insecticide to repel birds.
Q: Little tiny black ants are hollowing out my grapes as soon as they start to get sweet. I don’t like the idea of spraying the grapes with a chemical spray, but need some help in stopping this activity. I have two Thompson seedless and two seedless Flame plants. The ants are not particular about which one they eat.
A: I would suggest insecticidal soap sprays about every three days as the berries are starting to turn color. Another possibility will be a product called Tanglefoot, which is put on the trunks of the vines. This product is a sticky goo that is applied to the trunk and won’t allow the ants to cross the barrier without getting stuck.
Another possibility is to treat the colony in the ground with an ant bait called Amdro, which you can get at the mass merchandisers and nurseries. It works well and is applied to the nest just at the surface of the soil.
Q: I am hoping that you can help me to help my son. He lives in Southern California with a young family. In order to make ends meet, he has created a good size garden for his family to have fresh vegetables. Some of his tomatoes are getting ready to harvest, but his crops are being plagued by spider mites. He has released a large amount of lady bugs from his local nursery but they don’t seem to be solving the problem. Is there something that he can treat his crops with that will not contaminate the vegetables? Please give me some “fatherly advice” for him.
A: When your son purchases tomato transplants in the future try to find a supplier who is growing them by using only organic pesticides. Some growers will spray transplants with a hard pesticide to knock everything down before shipping them out. This way they get to market looking pristine and with few insect problems.
The problem with this approach is that spider mites are controlled by other insects and predatory spider mites. Once these predators are killed, any new infestation of spider mites takes off like a rocket since they reproduce so quickly and their predators are gone.
Spider mite population explosions are enhanced if plants are covered in dust. Wash them periodically, particularly after wind that may leave them covered in dust.
As far as chemical controls of an organic nature, try insecticidal soaps or horticultural oils or perhaps both. I have heard some recommendations that include the use of Neem oil, but people are recommending mixing a soap or detergent with the Neem oil. No, no, no. You must never mix a surfactant or any kind of soap or detergent with oils. This destroys the basic property of an oil that kills insects, namely suffocation. Use both of them, but use them separately or alternate their use.
Insecticidal soaps must be applied every three to four days, and must be applied on the undersides of the leaves to be effective. Never spray during the hot times of the day; spray only very early in the morning or late at dusk when bees have returned to their homes.
I hope this helps with your fatherly advice.
Q: This tree I have loses its leaves by Dec. 15 each year and comes back in the spring. I don’t know the name of the tree but I sent you a picture. It is about 9 years old and is on a small patch of grass. I assume there are drippers to the tree below the grass and there are normal sprinklers on the grass. The grass is doing good. The center and top section of the tree are not doing well and the leaves are small and underdeveloped. The lower branches appear normal. What makes the center and top section of a tree die and the lower outer branches do well? I do not have the ax out yet but will if conditions do not improve.
A: From your picture, the tree appears to be an ash. I think it may be either Fantex, Shamel or Arizona ash .
The problem is most likely right at the bottom of the damaged area. Follow the damaged parts of the tree to just below the poor growth.
See if you see damage to the trunk, the bark peeling away or holes in the trunk from sapsuckers (woodpeckers). I am thinking maybe you might see some sunburn and bark peeling due to sun damage, borer damage or sooty canker disease.
Shamel ash is susceptible to root rots due to overwatering but I think you would see this over the entire tree, not just in this one area. If you find damage to the tree in the spot where I am directing you, you may have to cut the damaged branches off. If you do, it will probably permanently deform the tree.
But take a look and tell me what you see. Perhaps you should sharpen the axe. It will not need to be sterilized.
Bob Morris is a horticulture expert living in Las Vegas. Visit his blog at xtremehorticulture.blogspot.com.
