Pomelo Orchard... Problems!

[samuijimmy]

There are dozens of "mature" Pomelo trees on the property I rent... My landlord (Thai) is an "office worker" & no idea about pruning, although he's good at buying "Moo Poo" (dried Buffalo Poo actually... ) 600 bags arrived the other day!

Sadly they have never been, properly pruned... more like rip & cut... (no clean cuts) full of cankers & witches broom & general fungus rots ... not to mention the blessed red ants, that make doing anything not a pleasant job ! I and one of the neighbours have been trying to cut out & burn the cankers... it's a very tedious job! Even he who is more of a gardener gets me jumping up & down, with his methods!

I have introduced them to a pruning saw on long pole, they love it... sure better than a Machete! (great by the way for cutting off the coconut branches, too (fronds is it?)

Some trees produce a reasonable amount of fruit, others hardly any at all.

My question (s)... Anyone have ideas of what to spray to help prevent problems... if written in Thai & English, that might be helpful! So I can show him what to get... (Lime sulphur - dormant oil, would be what I would have used in the west, on fruit trees... but not the same here!) ...

Will the suckers produce fruit? I suspect not, but they seem to want some to grow.... or some of them anyway

Any help appreciated!

[drtreelove]

There are dozens of "mature" Pomelo trees on the property I rent... My landlord (Thai) is an "office worker" & no idea about pruning, although he's good at buying "Moo Poo" (dried Buffalo Poo actually... ) 600 bags arrived the other day!

Sadly they have never been, properly pruned... more like rip & cut... (no clean cuts) full of cankers & witches broom & general fungus rots ... not to mention the blessed red ants, that make doing anything not a pleasant job ! I and one of the neighbours have been trying to cut out & burn the cankers... it's a very tedious job! Even he who is more of a gardener gets me jumping up & down, with his methods!

I have introduced them to a pruning saw on long pole, they love it... sure better than a Machete! (great by the way for cutting off the coconut branches, too (fronds is it?)

Some trees produce a reasonable amount of fruit, others hardly any at all.

My question (s)... Anyone have ideas of what to spray to help prevent problems... if written in Thai & English, that might be helpful! So I can show him what to get... (Lime sulphur - dormant oil, would be what I would have used in the west, on fruit trees... but not the same here!) ...

Will the suckers produce fruit? I suspect not, but they seem to want some to grow.... or some of them anyway

Any help appreciated!

Samuijimmy, You have taken on a big challenge by trying to revive trees that have been poorly pruned and cared for. Without seeing the trees or having a specfic target pest or disease to recommend spraying for, I would suggest that this should not be your focus; broad spectrum general pesticides and fungicides can be found in the organic growers tool kit as botanical extracts and formulations, but it's best not to use pesticides of any kind, organic or not, unless you have a specific target, and choose the least toxic alternative. Citrus trees do have some serious pests and diseases that require control measures, but that should be evaluated in respect of your local conditions and what other growers in the area are seeing.

What you describe as cankers could be wood rot fungus infections at the sites of old pruning cuts. There is no good spray solution for this; the tree will close over these wounds, or the branch will decline or break depending on the severity and extent of the decay.

It sounds to me like the best thing you can do is to let the sprouts regrow around the old pruning cuts, this growth will help the closure process and eventually become new branches that can be thinned to select a new strucural framework.

Yes the new growth on citrus can eventually produce flowers and fruit, as long as that growth is not below the graft where the root stock is from another variety.

For the pruning, sometimes less is better, especially if the trees were recently overpruned. Maybe let them grow out for a year or two in order to regain leaf-surface for photosyntheis and food production. Or if they have already gone a couple of years after hacking, and are very thick in foliage from the resprouting, you could consider going through and thinning, 'just say no' to heading cuts (stubbing).

Citrus do very well with manure fertilizer from my experience, but 600 bags is a lot and should be used intelligently. It depends on whether it is dried already or is fresh and hot, and how you are going to use it. A high nitrogen fertilizer will stimulate new growth, which you may want, or not; excessive rapid growth brings it own problem potentials.

If you post some pics of the trees, the cankers you are talking about, etc., I may be able to give you some more tips; and I may be sick but I'm dying to see what 600 bags of buffalo sh*t looks like; is that a 10 wheeler or what? don

[drtreelove]

After thinking about it, I realized that the 'cankers' may be sunburn.

Citrus are prone to bark damage from sun exposure if the foliage is cut back heavily; if this is the case you will see the damage on the woody stems on the southwest exposure (in the northern hemisphere), where the afternoon sun beats down and burns the bark and living tissue underneath, exposing the heartwood to wood rot fungus infection.

That's another reason not to over-prune and remove the shade and micro-climate effect of the full foliar canopy.

[samuijimmy]

Thank you for the responses Doctor Don...!

I am going to attempt to upload some images here... including the picture of the 600 bags of dried Poo... !

By the way, the extra bags that are left over are for sale, by the property owner... But I think Thai Post might have a problem delivering by mail... ... so limited to anyone on Samui who wants to contact me, & can pick up... 8o baht a bag... discount over 10 bags... )

You will need to turn your screens, the pictures have reverted side ways!

I hope this might give an idea of the mess these trees are in

Thanks again for any input!

Jim

Edited September 30, 2009 by samuijimmy

[drtreelove]

Now I'm going to need a chiropractor after viewing those photos.

The stubs from the old pruning cuts are decaying back into the stem; the heavy exudations are 'gummosis', oxidized sap that exudes from citrus, stone fruits and some other tree species with irritations like fungal and bacterial infections; it's not pathogenic itself, but a sign of internal disorder. Nothing really that you can do about it, except to clean up the pruning cuts and wait for them to close over with callus tissue. The gummosis exudations may continue for a couple of years.

The grey patches/encrustations on the stems are lichen, whether you lichen it or not, it is not a pathogen or parasite, but only an opportunistic co-existence where the conditions are right.

The twisted twig growth from the area of the old pruning cuts is just misdirected rampant growth from the extreme pruning cuts. You can prune that out and leave a few of the better formed sprouts that are straight and in a good position to become new branches.

The buffalo poop is brown gold for the farmer; one sack per tree sounds about right and not excessive, dried is okay for direct application, if it is fresh and wet you should maybe compost it.

htprune.pdf

Edited October 3, 2009 by drtreelove

[samuijimmy]

Thank you, Doc! ,

Sorry about the pictures being sideways... Perhaps when I get a few spare moments I will try to repost the pictures... so I don't give every one a pain in the neck!

The PDF file is very useful, so anyone out there who about to do some pruning should read it first! Having been a professional gardener /horticulturist most of my working life, I know most of the principals .... just needing to learn more about the 'tropical trees" .... of course trying to clean up the hack & prune methods, makes it more difficult ! ....

There always something to learn when it comes to gardening, it does not matter where you live!

[drtreelove]

There always something to learn when it comes to gardening, it does not matter where you live!

Man, you're right about that; always something to learn!

I sympathize with you on trying to straighten out a tree after it's been hacked; I've always considered that kind of re-constructive pruning the most challenging. Just cut what is obvious to you, where you can see something that clearly needs to be done. If you're not sure, it's usually better to let it go and move to something more obvious. You can always come back and look at it again.

The rule of thumb is not to take out more than 25% of the foliage at one time, in a one year period; sometimes specs say two years. The point is that leaf surface is important and taking too much green puts the tree in a stress condition and it either responds by excessive shoot growth, or if it is a tree that doesn't sprout vigorously (like a pine), then it can decline in health or die. So it's best not to overdo it, light pruning for thinning and structural corrections is best.