I don’t want to apply high N 46-0-0 urea at the wrong time.
What’s the best time of year or fruiting stage to apply it?
Best info that i have seen on the topic… wiser advice likely to follow from Olpea.
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Suggest checking your rainfall history to see when spring rains will diminish if you plan to use natural rain to carry the urea into the soil. There will be a time lapse between application and adsorption by the plants so allow at least several weeks before fruit set.
Dennis
Kent, wa
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Granular or water soluble powder? The granular is functionally weaker when broadcast in orchards because much of it evaporates into the air. Depending on climate the effective concentration is around 13-0-0 – which is more appropriate for the trees after fruit set. The water soluble powder is more cost effective provided you have a means of diluting it in water to the desired dosage and then applying to the trees. In this case the grower can consider staggered applications in Spring and Summer of different concentrations.
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Is it difficult to dilute? And would that be a foliar application or is the mix applied within the drip line ?
No, but it is difficult to disburse to a large number of trees by hand.
Foliar is a good choice for a moderate number of trees in a suitable climate, fertigation is the method of choice for ground application to more than a few trees.
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?
The granular is functionally weaker when broadcast in orchards because much of it evaporates into the air.
There are uncoated and coated urea. The uncoated (regular) urea is the one that people are concerned about volatilization loss.
Here’s info from Cornell.
http://nmsp.cals.cornell.edu/publications/factsheets/factsheet80.pdf
I have applied urea to my peach/nectarine trees when growth starts in mid spring (mid April here).
@Olpea would be the person who can give you the answer.
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Has the same problem when broadcast on the exposed surface of an orchard.
who can give a great answer for his climate.
It is little white crystals. I would cover it with mulch so hopefully it wouldn’t evaporate too much
Depends on the weather, soil surface moisture, irrigation, etc. If applied in ideal circumstances, there is very low loss.
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Very interesting reading. Thanks
Very interesting reading.
My trees already have fruit but some have a split shuck still attached, so I’m not sure if it’s too late for this Spring but I was thinking maybe a late season application would be good for next year
My statements here are based on professional experience, not casual reading.
Richards chain of command I have gathered so far
= Experience > Reading > Youtube > Guessing > Malice
But seriously I forgot to rinse a spray can I used for diluted ammonia granules… Next time i filled it and pumped pressure the metal neck of the nozzle exploded apart. Super corrosive stuff.
You words gave me an idea. Can I dissolve urea in water and feed the trees that way? Not spraying on the leaves but pouring on the ground around the tree
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yeah, this is what I was trying to do basically spray 50ml per plant etc, but beware of corrosion on metals, rinse well. I think plastics also degrade faster after interaction as well.
I have done that many times (dissolving in water and and feed the trees). It is my amateur experience.
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Earliest spring app assures trees have optimum N at the first formation of fruit, which helps increase size without sacrificing flavor because size is gained by greater cell production in the first few weeks of development and not larger cells.
Commercial growers often use fertigation well into summer to assure adequate vegetative growth for tree health and nice shoots for next years crop. Also, especially for the rapid establishment of young trees not yet in production.
I like to use 90 day coated urea for peaches that I’m trying to make bigger, but quick release once they are established… same as establishing apples, pretty much, but the peaches get more. If by summer they aren’t showing quite the vigor I want, I may apply another shot of straight urea.
Urea doesn’t leach the same way nitrate does (bonds to soil with its charge) particularly in sopping soil, and for best tree absorption takes a few days for most species to utilize as ammonium. Peaches are ready to begin absorbing ammonium efficiently by first green.
When there’s no rain in the forecast and I’m applying fast urea, I also will put a cup of it in a bucket to feed a tree, or even if it is when I’m in a hurry to juice a tree up. If you leave it in the bucked for a few minutes before stirring it dissolves nicely, especially in warm water.
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Same here, we apply urea to dry ground and irrigate. If you have any studies indicating 60% loss due to volitilization, I would be interested in reading them. I have seen some indicating application under the worst conditions can lead to significant loss.
This may be a climatic difference between our regions though. We are in a dry climate with the ability to irrigate
early in the morning to incorporate immediately. All studies I’ve read indicate about a 5% loss under these conditions.
Also, sorry if I came off as defensive. We apply about 2 tons of urea every year, so I don’t want to be wasting that much money. I think we are talking about two different sets of conditions though, so it may not be applicable.
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