Zinc or Manganese deficiency? Will fish emulsion/kelp take care of it or will I need to add something stronger? Thanks.
Zinc is more commonly deficient and is what I’ve had. With zinc the leaves are smaller and extension growth is reduced. I can’t tell you if that’s what you have. Mostly I’ve sprayed a little zinc sulfate or chelated zinc. Can’t say that either helped a lot and the problem wasn’t severe. Mostly to upper zones of the canopy not the whole tree.
Unless severe probably not a real concern for a home orchard.
Although the advertising and front labels of kelp products proclaim numerous minerals, the fact is the minerals are largely in a form that is inaccessible to plants. You can verify this by reading the “Guaranteed Analysis” section of the label which by law only lists nutrient content viable for plant use - either immediately or by release through soil processes. Kelp fertilizer is a plant hormone product and should not be confused with plant nutrients.
This is what I am seeing. It isn’t the whole tree, just certain parts.
Did not know this. Thanks Richard. I do have other fertilizers that guarantee zinc, manganese, and other trace minerals. So if the problem gets worse, I’ll start using those. I have so many plums (for the first time ever) on my tree and want to make sure I do as much as I can to make sure they grow and ripen properly.
Thanks.
From the picture my guesses are:
slight phytotoxicity from pesticide, or
nutrient binding due to alkaline water, or
excess dosage of alkaline mineral nutrients.
No pesticides but we do have very alkaline water I believe. If the problem gets worse, maybe I’ll start using some of the blueberry fertilizer I have (Jack’s Acid Special) that is supposed to lower ph levels.
When irrigation is a plant’s dominate source of water, then the pH of the irrigation water tends to set the pH of the soil. If possible, I recommend doping the irrigation water at every feeding to lower its pH. Use a fertilizer with NPK appropriate to the plant. Since many water-soluble products are buffered, a small dosage such as 1/4 tsp per gallon is often sufficient for moderately alkaline water. Do not exceed what would otherwise be one fourth of a monthly dosage or 1/12 of a 3-month dosage.
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UC Davis has good info on Zinc and other nutrient deficiences.
My symptoms have never been nearly as bad as say picture number 3 in the link. Those trees are so deficient that the tree has basically quit growing and leaves are very small.
I seriously doubt that we are looking at nutrient deficiencies but instead at nutrient blocking by excess alkaline minerals including but not limited to potash and calcite. Anaerobic bacterial root infections are also possible for the symptoms. These kind of “deficiencies” usually cannot be overcome by supplying more of the symptomatic mineral, but instead by correcting the imbalance in the soil. A temporary reprieve for the plant can be had by foliar application of the symptomatic blocked nutrient but in my experience it will not sustain the plant in the long run.
Clemson also has a good site
http://www.clemson.edu/extension/peach/faq/peach_nutrition.html
Hello, we have similar issues here. It is caused by alkaline soil which blocks the uptake of iron. Worse on peaches than plums. We are on limestone clay with chunks of limestone throughout. We spread sulfur to try to neutralize the soil. Your extension service can tell you the amounts to use when you get your soil tested. We use surface water for irrigation so don’t have the water problem (our well water is also alkaline). You can add sulfuric acid to your irrigation water to counteract the alkalinity (organic acids will not work because they break down into CO2 and water leaving the basic minerals in the soil) try for a neutral pH. Unless you have a injector on you irrigation system it will be a pain to accurately mix in the acid. Probably filling a 50 gal drum and adding a measured amount of acid, mixing, check the pH (strips) then trickling out of the drum would be the easiest.
Will Ironite provide the nutrients the trees need or will the alkaline soil block those nutrients in that form as well?
Ironite is a brand name for fertilizers – their original product once contained significant concentration of iron chelates. Not so today. I’d recommend you look for an individual supplement instead.
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