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Author Topic: new growth flushes turning yellow/white  (Read 631 times)

brian

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new growth flushes turning yellow/white
« on: June 23, 2019, 09:09:34 PM »
Recently all my in-ground in-greenhouse citrus had large growth flushes.  The new growth is looking very yellow/white now.  It seems to match up with spider mites, the trees that haven't had much spider mite activity are still nice and green, but the ones with the most spider mites are most affected.  Are spider mites the likely cause, here?  Or is this more likely a nutrient deficiency? 

I just did a ph test and soil is ~6-7ph.  I added a handful of osmocote to each tree a few weeks ago.  Soil doesn't seem wet, at least in the top inch or two I could dig my finger into. 

All my container-grown trees outside are unaffected. 

Here's the Flame grapefruit (I think):


And the Moro has some really bad areas like this:



Even the Valentine Pummelo that Millet sent me is affected, and it is on flying dragon.  The rest either I don't know the rootstocks, or they are some non-optimal ones like C35

TooFarNorth

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Re: new growth flushes turning yellow/white
« Reply #1 on: June 23, 2019, 09:28:11 PM »
I believe that I would try some 10-10-10 fertilizer for in ground trees.  It almost looks like sunburn.  Is it only on some new leaves, or pretty much all of them?

TFN

brian

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Re: new growth flushes turning yellow/white
« Reply #2 on: June 23, 2019, 09:39:07 PM »
Pretty much all of the new growth on the affected trees.  It gets hot in my greenhouse, BUT all the trees I have sitting outside in unfiltered look fine. 

Im looking at spider mite leaf damage photos and the fine specking looks just like recent damage ive seen.  I wonder if the mites have been active a lot longer than i realized and i didnt notice until webbing appeared?

Millet

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Re: new growth flushes turning yellow/white
« Reply #3 on: June 23, 2019, 11:01:57 PM »
it certainly look like spider mite damage.    I have been spraying my trees twice a day with water spray.  Upper and lower leaves.  Evening sprays work well.  Spider mites hate water.    Oil sprays also work well.

brian

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Re: new growth flushes turning yellow/white
« Reply #4 on: June 24, 2019, 09:58:08 AM »
Im going to try spraying them more aggressively.  I was reading about spider mites last night and saw that they do not tolerate high humidity, so simple water makes sense.  Also it seems they tend to decline on their own by mid summer, though i dont know how that schedule applies to a northern greenhouse.  All the research reports are from citrus growing states.

Ilya11

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Re: new growth flushes turning yellow/white
« Reply #5 on: June 24, 2019, 10:04:32 AM »
Spraying with horticultural oil emulsions is very efficient against spider mites.
Best regards,
                       Ilya

Millet

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Re: new growth flushes turning yellow/white
« Reply #6 on: June 24, 2019, 10:07:26 AM »
Yes, the water sprays raises the greenhouse humidity level.  Especially the evening spray keeps the humidity up through the night.  So far spraying has worked very well in my greenhouse.

brian

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Re: new growth flushes turning yellow/white
« Reply #7 on: June 24, 2019, 10:19:00 AM »
I have hort oil but Iím really worried about cooking my plants as it is sunny this week and its over 100F in my greenhouse when the sun is out.  How long after spraying dilited hort oil are plants considered back to normal in terms of heat tolerance?

shaneatwell

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Re: new growth flushes turning yellow/white
« Reply #8 on: June 24, 2019, 11:21:20 AM »
I have this too, but I don't think mine is mites. Have it on my mamoncillo and peanut butter tree, but only the grafted branch. Also recently grafted mandarin. Last year it was my glycosmis. Seen it on other citrus other years. I think it has more to do with the exact timing of the growth flush and either temperature or soil moisture. Like the flush starts but the temp isn't quite high enough for soil nutrient mobility.
Shane

Millet

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Re: new growth flushes turning yellow/white
« Reply #9 on: June 24, 2019, 02:51:01 PM »
Brian, you need to find a method to reduce the day time temperature.  Temperatures 100+ for the entire summer months will not be good for your trees.  Before I put a Wet Wall in my greenhouse my fruit level was very low, and growth was non existent.

brian

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Re: new growth flushes turning yellow/white
« Reply #10 on: June 24, 2019, 03:26:49 PM »
I just got my fog pump working today.  I discovered two of the fog nozzles are leaking badly so I need to get replacements, and maybe another thermostat.  Hopefully the fogger will keep temps reasonable but them I will see if I have problems with hard water damaging plants.  My TDS meter says 190ppm for my water supply. 

Might try shade cloth also/instead.  Still figuring this out.  Do you think this damage could actually be sun burn?  I always assumed sunburn was due to intense UV+heat.  The polycarbonate filters all UV, and maybe 20% light when you include angles, greenhouse frame, etc.   My outdoor trees seem perfectly happy in direct sun 10hrs a day, though outdoor air temps are 80-90F while greenhouse is 100-110F.

I could also run my fans faster, they get loud though.

Laaz

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Re: new growth flushes turning yellow/white
« Reply #11 on: June 24, 2019, 04:59:11 PM »
We have temps in the 90's-100's for months here. All my citrus are in full sun & never burn. Usually the only way you'll get sunburn is from moving plants with new growth from shade to full sun without acclimating them to the sun.
« Last Edit: June 25, 2019, 05:00:47 AM by Laaz »

brian

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Re: new growth flushes turning yellow/white
« Reply #12 on: June 24, 2019, 06:27:13 PM »
Im going to assume it is just the spider mites, then.  My trees have been in ground there for months.  Id still like to be able to keep it reasonably cool, though.  Ill see how effective it is soon

Millet

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Re: new growth flushes turning yellow/white
« Reply #13 on: June 24, 2019, 08:18:12 PM »
If the damage to your trees is from spider mites, as bad as your leaves look, you should see some spider mite webbing. Fogging the greenhouse will raise the humidity to a level that will eliminate any mite problems, and make life comfortable for your trees.
« Last Edit: June 24, 2019, 08:20:16 PM by Millet »

brian

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Re: new growth flushes turning yellow/white
« Reply #14 on: June 24, 2019, 09:19:32 PM »
I see spider mite webbing and spray it off every day or two, but much like the cottony cushion scale they come back with a vengeance

Millet

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Re: new growth flushes turning yellow/white
« Reply #15 on: June 24, 2019, 10:39:51 PM »
We do not have Cotton Cushion scale in Colorado, therefore I have no experience with them.  Can't CCS be blasted off with a strong spray of water using an adjustable brass nozzle?

brian

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Re: new growth flushes turning yellow/white
« Reply #16 on: June 24, 2019, 11:01:54 PM »
CCS is very.. sneaky.  They thrive on the underside of leaves and the least accesible areas to spray

Laaz

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Re: new growth flushes turning yellow/white
« Reply #17 on: June 25, 2019, 05:03:07 AM »
If humidity was the key to controlling spider mites we wouldn't have them here, but we do...

Oolie

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Re: new growth flushes turning yellow/white
« Reply #18 on: June 25, 2019, 01:26:04 PM »
Most mites are put off by humidity, so a humidification regimen, or spraying the undersides of leaves consistently can ward them off, works great on any spider mites we get on solanaceous plants here.

The bleaching of the leaves though likely due to mites, could also be a result of Iron deficiency.

I would foliar feed with Iron rich fertilizer or supplement to cover the bases while they recover. That would also supply humidity to help route the mites.

brian

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Re: new growth flushes turning yellow/white
« Reply #19 on: June 25, 2019, 03:44:58 PM »
I've read that foliar feeding iron doesn't work for citrus, though the explanation for why doesn't make sense to me... "citrus does not translocate iron well" was the gist of it.  I don't see why it would need to move if sprayed directly on leaves.  I have chelated iron I can add to the soil which I understand is effective.


Today a breaker tripped in my greenhouse had no power for a half hour or so, and temps reached 130F!  Unfortunately I can't tell what tripped the breaker so I don't know if it will happen again.  Plants looked fine when I switched the breaker back on, few had leaves a bit curled but I think they'll be okay.

brian

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Re: new growth flushes turning yellow/white
« Reply #20 on: June 25, 2019, 03:47:03 PM »
If the damage to your trees is from spider mites, as bad as your leaves look, you should see some spider mite webbing. Fogging the greenhouse will raise the humidity to a level that will eliminate any mite problems, and make life comfortable for your trees.

I definitely have spider mite webbing on the affected areas.  I had just sprayed them off with the hose before taking those pictures.  I've been doing this every few days but I think I need to be more persistent.

Millet

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Re: new growth flushes turning yellow/white
« Reply #21 on: June 25, 2019, 08:57:32 PM »
brian, temperatures of 100+is spider mite heaven.  Be persistent,  Also spray the ground under the trees.

brian

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Re: new growth flushes turning yellow/white
« Reply #22 on: June 25, 2019, 09:25:17 PM »
Just sprayed them as the sun was going down, will try to keep it up for the rest of the week

spaugh

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Re: new growth flushes turning yellow/white
« Reply #23 on: June 27, 2019, 10:29:12 AM »
How about some spinosad spray?  I would probably spray the entire GH down with it at this point you have little to lose.  Those plants are looking like goners soon. 
Brad Spaugh

brian

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Re: new growth flushes turning yellow/white
« Reply #24 on: June 27, 2019, 10:45:56 AM »
I have tanglefoot on all my tree trunks, so I'm hoping that will cut down on re-infestation if I can get the foliage clear. 

I've never used spinosad.  I see various miticides recommended for spider mites but I don't know if I can obtain them on my own.  Have you used this before?

 

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