Help with very sick trees

[desertgardengirl]

Hello fellow fruit growers. I am new to this forum, but belong to several groups on the internet and facebook. I need some help very 2 very sick citrus trees, a Flame grapefruit and Naval Orange. The following is a summary that I hope will provide the right kind of information.
I live in the low desert of Arizona. Trees were plannted March 2014, next to each other about 5 feet apart. They have been growing OK, and started into rapid decline about August this year. After an unusually hot summer, I first thought they were just heat stressed. Green leaves started dropping like crazy and the trees were beginning to look bare. I then noticed the black and rust colored spots on the grapefruit, which have now spread to the orange too. Watering, soil etc are always a factor, but for this beginning summary I will briefly say that I follow the local fruit growers group recommendations, regular fertilizer, foliar feeding every 2 weeks, heavily mulched etc. At this point both trees continue to decline and look so sickly that I am wondering if they can be saved at all. I have sprayed with copper 3 times in the last 2 months (you can see the bluish residue on some of the closeup leaves). Also, the leaf color in the pics is much greener than they actually are, as I guess the HDR setting was turned on in my camera app. Most of the leaves, especially the new growth, are all very light, almost whiteish or mottled yellow. Reading every bit on information I can find about disease/deficiencies, they look like they suffer from everything known to man. I don't know where I would even start with trying to correct individual nutrient deficiencies. Although I believe it is still not all that common in Arizona, I am beginning to wonder about "Citrus Greening". The grapefruit has a ton of fruit on it this year, but all are half their normal size and the skin color is staying green. I know fruit color has nothing to do with citrus greening, but thought the coloring might have some significance overall. The fruit is juicy and normal sweetness and color. Please let me know what you think. I can provide more pics and info if needed. Thank you, Linda

[LaCasaVerde]

Linda sorry to hear this news. To me looks like a bacterial/fungal leaf disease coupled with nutrient difficiency.  Here is what I recommend. Begin removing all the factors that could create/contribute to your leaf issues-

 If heavily mulched as you say -pull it away from the base of the trees by at least 12 inches or so. Mulch holds water- yes and keeps moisture- yes but also provides a great humid  area to breed fungus/bacterial diseases as it is constantly  moist. I have had the exact issues I see in you pics in the past.  It appears   bacterial or fungal spot/disease had set in on leaves. You sprayed   with copper  will  should arrest the progression but the damage to the leaves themselves will not go away.   Leaf drop is the plants way of getting rid of the problem and is normal.  Make sure to remove the leaf litter from under the tree as it will overwinter in the damp mulch  and return again in the spring. 

The pics with the leaves showing green veigns is not symptoms of Citrus Greening but nutrient dificiency. What is the ph of your water/soil there? Something your doing- or the soil that is around the plants roots - is limiting proper nutrient uptake causing the leaf chlorisis.  Citrus likes 5.5-6.0 . Citrus greening crosses the veigns and is blotchy and non symetric on the leaves. Black splotches or burned leaf tips are not typical symptoms.

What are you foliar feeding with this time of year? Id stop foliar feeding  for a while.  It is really easy to cause leaf damage if the follir mix you are using is too strong. Mix that with high temps and it becomes even easier to damage the leaves.  To rule this out I would just rely on fertilizer you have already applied until spring. No need to add more this time of year anyway. Wait until bloom to start your fert program again. 

Leaf curl can be caused by several diseases  as well as nutrient deficiencies- usually of the minor elements. Ill leave that to someone else to diag that. That said, the leaf curl - nutrient deficincy in my opinion

Smaller fruit- heavy fruit set most likley- thin to have larger fruit

Warmer weather- slower to yellow  fruit
 

The idea is to limit contributing factors to your leaf concerns. Any and all of the above can work in tandem and further stress your plant. Begin to treat this plant by being patient- as often ,discovering what the cause is,  is harder than actually treating the plant.

[JJROSS54]

Hi Linda
How are you watering your trees?, here in Arizona you need to deep water citrus to keep the salts leeched away from the root zone, our water here has a lot of salt and is a common problem if you water to often and shallow. From the looks of some of the leaves that are burning from the ends  looks to me like salt uptake. Deep water less often is what is recommended by all of the local nurseries here
The curling leaves are just a local insect called Thrips and they don't really hurt, they just make things look bad.

[desertgardengirl]

Not sure how to post individual replies to both of you, so will sort of combine here. Thank you both for time and information.
I am not sure of the exact PH of soil and water, but both are known to be high and alkaline here. I pulled the mulch back from surrounding the trunk about 1 foot in September. I do deep watering, and test with a rod to a depth of 2 - 3 feet to be sure the roots are not standing in water before watering again. I am continually learning and fine tuning my tree watering and care, and admit that the watering routine has not always been perfect. I have been foliar feeding with Urban Farm Apples & Oranges, with plenty of micronutrients. Also my regular fertilizer has all the micronutrients too. I foliar fed once a month Sept thru Dec, since it is recommended to help against winter cold, but will discontinue for now as you suggest. I know the usual signs of thrips and leaf miners, so sprayed with Neem Oil a couple times to try to limit the damage to what little new growth flush I was getting in the fall, but new growth just looked worse and worse. I also tried one spray with Sevin to see if that would help for insects, and no visual improvement there either. If you think the trees can be saved, I am thinking of removing all the fruit from the trees to hopefully relieve some of their load stress. Patience is not usually my strong suit, but I will do as you suggest and hope to see some improvement and a good spring flush. What little growth there was this fall is completely shriveled, deformed, discolored, and usually drops and ends up in more tip dieback. I have been keeping the dead tips trimmed off so I can track any progress, and yes I do sanitize my clippers continually. Thanks again for your help.

[LaCasaVerde]

Let the fruit ripen at this point. Looks like you are close anyway to harvest.

 Ive had aphids cause leaf curl on new growth.   Malathion spray kills them. They are visable to the eye. Thrips can as well as JJROSS54 said. Ive always had those issues though in the spring first flushes here- it may be different there.  Looks like all your curled leaves are fairly new growth so that may be the answer to the curling issue. High heat can also cause this...which you said you had. from

 http://mgorange.ucanr.edu/Edible_Plants/?ds=530&uid=108

2. Overwatering can cause leaves to curl or cup INWARD. Also, stress from very hot weather will cause leaf cupping

Dont ask a big box store but go to your local nursery when you get a chance and ask them what soil amendments if any would be recommended. I would ask  the owner as the information tends to be more reliable.

Dont worry Ive had citrus plants that were completley defoliated come back. They are pretty hardy. Your plants dont look that bad at all, just need to tweek the variables to see whats going on.

Not familiar with Apples & Oranges Citrus and Fruit Tree Fertilizer but looks to be a super concentrated fert.
Id be looking at the salt and ph issues.... that is a good question for the nursery there as well as using this as a foliar spray and at what mix ratio.

[Millet]

The leaf curl on the young leaves was caused by insects.  This happened when the leaves were young and tender.  It's too late to correct it now.  Spraying the young leaves until they harden up with horticultural oil avoids the problem. A lot of your leaf burn looks to be from high soluble salts, You need to water deep to flush away the salts.  You should get your water tested also for bicarbonates.  If you water has high carbonates or bicarbonates, which it probably does,  each watering adds to your trees problems.  My well water had that problem and caused the same foliage problems.  I have sense switched to rain water. The second picture is an iron deficiency, probably caused by the high pH of the Arizona soil.

[Millet]

Linda, if your irrigating your trees with municipal water, you can call your water company and they will tell you the pH , bicarbonates, and  total alkalinity (as CaCO3) content of your water. Total alkalinity should be  <100 for irrigating citrus.

[desertgardengirl]

Linda, if your irrigating your trees with municipal water, you can call your water company and they will tell you the pH , bicarbonates, and  total alkalinity (as CaCO3) content of your water. Total alkalinity should be  <100 for irrigating citrus.
Thanks Millet for this tip. Collecting info is especially helpful when you know what you are looking for.

Thank you LaCasaVerde for your additional information and encouragement too. I am in the process of turning my small backyard growing area into a food forest. The orange and grapefruit were the first two trees I planted almost 3 years ago, and planted most of the other trees in the last year. I am constantly learning and wish I knew then what I know now, but still far from knowledgeable. Once something is derailed, it's hard to figure out how to get back on track. There is no doubt that I have done many things wrong with these trees in particular, but with the help of knowledgeable people on this and other forums, I hope to do better going forward. I know water is a big problem here, and I have set up a couple rainbarrels, but with my limited space and low rainfall it is literally a drop in the bucket when trying to water so many trees and plants. I will use all rainwater available on the orange and grapefruit for the next couple months in hopes of helping their recovery. I also changed my drip watering to bubblers this fall, which I hope will improve the watering part of the equation.

[desertgardengirl]

LaCasaVerde
Thanks for the link, I finally got time to read it thoroughly and it is really good straightforward advice and info.

[Millet]

When you have a soil salt problem, the drier the the soil around the root zone becomes the higher the salt concentration becomes.

[JJROSS54]

The salt problem in our area is the water more than the soil, this is the reason all of the local nurseries recommend deep watering to push the salts on down away from the root zone, this time of year deep water every 2 or 3 weeks and mid summer when we are 100+ once a week or more as needed but just do not shallow water every few days, this just lets the salt content from the water increase in the soil, then when things dry out a bit the trees takes up the higher concentration of salts and you see the leaf burn.
I only live about 10 miles from her so I have the same conditions as she does.
This area grows some great citrus but it is all flood irrigated so they are watered nice and deep.

[desertgardengirl]

The salt problem in our area is the water more than the soil, this is the reason all of the local nurseries recommend deep watering to push the salts on down away from the root zone, this time of year deep water every 2 or 3 weeks and mid summer when we are 100+ once a week or more as needed but just do not shallow water every few days, this just lets the salt content from the water increase in the soil, then when things dry out a bit the trees takes up the higher concentration of salts and you see the leaf burn.
I only live about 10 miles from her so I have the same conditions as she does.
This area grows some great citrus but it is all flood irrigated so they are watered nice and deep.

Thanks for the additional info. I have had a basic understanding of this, but your post and the last one from Millet help to make this more clear to me. I will be much more diligent in developing my watering schedules on these and all my trees.