Xtremehorticulture

Pluot Can Have Sap Oozing Like Both of its Parents

Q. We planted a pluot this past spring along with four peach trees of different varieties. The pluot just started oozing sap or gumming on the lower truck. All of the trees were planted as bare root trees. The trees have a bermed area for holding water with wood chips for mulch. I am watering two to three times a week and frequently check soil moisture around the roots with a very long screw driver. A. In peach, gumming or sap coming from the trunk or limbs, is frequently due to borers. In both plum and apricot (the parent trees of pluots) gumming can happen without borer problems. Frequently it is a sign of stress. Sap oozing from trunk even with trunk painted             Make sure that the trunk and limbs are in the shade of its own canopy to reduce sunburn from direct sunlight. Sunburn damage can cause this as well. Paint the trunk and limbs with diluted white latex paint to reduce sun and heat damage to these areas.             Dilute white latex paint with an equal amount of water and either spray it or brush it on. This will reduce the surface temperature of these areas about 5 to 6 degrees. We normally do this in the winter when we don’t have to fight with the leaves and after pruning is done.

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Young Apricot Leaves Drying Up and Liquid Oozing

Q. I planted a Blenheim Apricot in March.   At first it did not seem to take but within four weeks it began showing growth whereas all the other fruit trees took almost immediately.  Its been doing fine until just recently when I noticed some of the leaves on the main truck were drying up.   I check the moister level regularly.   Looking closer at the graft there seems to be some liquid oozing out.   Enclosed are some photos of the liquid, drying leaves, and tips of higher leaves.   Any thoughts on what I’m up against.   Rootstock is Citation Hybrid if that helps. All my other fruit trees planted in the same general area are doing just great. Iron chlorosis, inter veinal chlorosis, or yellowing between the veins typical of new growth when iron chlorosis is present A. Some great shots and I would like to post them on my blog. Your photos tell a nice story I dont get to tell very often. But first lets look at the obvious and the is the discoloration of the leaves. The yellowing between the veins is called “interveinal chlorosis”. Chlorosis just means “yellowing” so it is yellowing between the veins. The most common reason for this in our alkaline soils is nutritional and frequently it is a lack of iron. Other nutrient deficiences that can cause similar types of chlorosis can include manganese and zinc deficiencies. I would guess this is an iron problem. The picture of the sap at the place where the rootstock (in this case Citation) meets what we call the scion (in this case yours is Blenheim apricot) we see some damage. It is very close to the bud union or dogleg (where the two meet). Bud union or dogleg. Where the Blenheim apricot was budded or “grafted” on to Citation rootstock and sap The damage may have started at the time of planting and is most likely from sun damage or sunburn. This area should have been painted with whitewash or any diluted white latex paint. Dilute 1:1 with water. Or you can put anything in front of that area that would give it some shade until the tree puts on some canopy and shades itself. You can use wooden shingles, cardboard, anything to cast a shade on the trunk. Usually, if the trunk gets sunburn then it is highly likely it will also draw borers to the damage and you will get borer damage there. It is very likely this is what you are seeing. YOu can find out easily by bending the canopy of the tree over. If the trunk breaks, it will break at the borer damage and you will most likely see them there. If it does not break when you bend it, it may just be sunburn. If the sunburn is not extensive, it is posssible it could heal itself but rather unlikely. You may have lost the tree. Interestingly, this dunburn and damage at the dogleg can also lead to the chlorosis or yellowing of the leaves as well. The sunburn damage can interrupt the flow of nutrients including iron up the tree and the interruption may be enough to limit the supply of available iron and lead toward iron chlorosis. However, some iron chelate sprays on the leaves a few times, along with a teaspoon of Ivory liquid per gallon of spray, may be enough to green the leaves up. I would guess 4 to 6 applications made in the wee hours of the morning when it is cool. Next time whitewash the trunk at the time of planting or provide some shade on the trunk until the canopy gives enough shade to protect itself.

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Branches Dying in Elm Probably Not Dutch Elm Disease

Elm leaf beetle damage Q. I have about 10 elm trees and my neighbor has 4 or 5. The branches seem like they just die. This pass year I lost 2 complete trees. I have been told there is a elm airborn disease. Can you please tell if that is true and what can I do about it? A. There is no airborne disease of elms that you have to worry about. I think there is some confusion about Dutch Elm Disease and these trees. Siberian elms are not as susceptible to DED as some other elms which are not planted here anyway.             Most of the elms here are Siberian elms, an inferior elm for landscape purposes. By the way, one of my favorite large trees is Chinese or Evergreen elm, a very nice tree that grows well in our climate with very few problems.              The usual disease problem we see on Siberian elm is a relatively harmless disease called slime flux. This is a bacterial disease which invades the wood and causes basically fermentation inside the trunk and large limbs. ooze from the bacteria is pushed out of the trunk or limbs and weeps down the side of the tree frequently from a pruning cut. If you get close to this ooze it will smell like fermentation or yeasty. Wetwood or slime flux comig from pruning cut             This smell frequently attracts flies to the ooze. It is thought that the flies can pick up this bacterial contamination and spread it to new wounds on several trees besides Siberian elm. If we see this particular disease on the tree we usually ignore it since it really does not cause any long term ill effects.             As far as insects go the worst problem is elm leaf beetle which skeletonizes the leaf. We usually ignore this too since it usually does not cause severe damage to the tree but does cause the leaves to become unsightly. These trees are tall/large with the leaves very high in the air so damage to them is usually ignored. It would be very costly to spray these trees to control this problem.             The last problem we have had with Siberian elm is when older landscapes with these elms growing in lawns is converted to rock landscapes. Frequently there is not enough water applied for these trees to continue to be healthy and the branches die back due to lack of water and a poorly designed irrigation system for the elm to survive.

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