Most of the people on this forum like me who are growing citrus outside are growing in traditional citrus growing areas like so cal and the US southwest where the air is hot and dry.

In addition to this forum I would research florida state U and other university websites where citrus in grown in a more tropical humid environment like yours. jon

Hi, thanks for the reply.

A wide variety of citrus trees are very common in yards here, but I guess few people in Hilo are on the internet. :) My previous rental house had an orange tree that made wonderful juice oranges.

Native trees of the citrus family are also abundant throughout the native forests - wet, mesic or dry - though they produce only seed pods instead of fruit. Here's my native rutaceae photo page, with melicope, platydesma and xanthoxylum galleries:

http://www.pbase.com/bkrownd/rutaceae

brooks

This post was edited by bkrownd on Sat, May 31, 14 at 16:48

The soap should be for horticultural use. If you use only Neem oil repeatedly you risk having pests build up a resistance.

Some scale is controlled with oil.

Johnmerr needs to chime in here about tropical citrus.

I've been spritzing them with neem and insecticidal soap every other day for a week or two, but the various infestations (mites, fungus, scale and miners) seem to be spreading. :/ Could the twice a day rains just be washing it all off?

The ants aren't deterred either, so I guess I should put some kind of barrier on the lower trunk since the ants seem to be involved in the problems.

I think I need to seek out a fruit tree book before I add components to the spraying campaign.

I added Safer soap with sulfur to my arsenal. I'm trying to spray more in the morning, to avoid the regular evening/night rains washing the spray off right away. It's working for my citrus trees now. Infestations of scale and fungus are in retreat! Ants are less interested. I can't say whether there is any change in the leaf miners.

Tahitian lime:

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Kaffir lime:
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This post was edited by bkrownd on Sat, Jun 7, 14 at 15:10

Okay, first, if they were my trees I would treat them with a systemic that goes a long way to controlling insects that eat or suck on the leaves. You must control the ants; if you have ants you will have aphids. I don't think ants bring the scale; that is more commonly brought by birds. Depending on what type of scale you have, the systemic will keep it pretty much under control; for my garden plants I control scale by hand; but they are the larger type that are easy to see and remove. Once you have the scale under control, regular inspections (get yourself a 10x loupe) and removal by hand or with Q-tip and alcohol is fairly easy.
Now, because you are in the tropics you will also have fungus/mold problems, which you need to keep under control, especially if your trees are close together; again a systemic fungicide makes life easier. Ask your local nursery what type of systemics you can access.
For the unknown 10 ft tree, if you can post a photo of the tree, a closeup of the leaf and maybe a photo of the fruit and a cross section cut at the equator of the fruit, someone here can likely give you a pretty good guess as to what it is.
At that size and regular production, could it be a Meyer lemon?

Thanks for the reply!

Someone I work with suggested scorching the ground around the trees with a propane torch to discourage the ants. Apparently that works for him - they really don't like crossing the scorched earth. While it would also help with some nasty weeds, that's a bit too intensive for me. ;)

The large orange/lemon trees I've had always had ant infestations without showing any obvious harm, and produce huge quantities of fruit. I was thinking about perhaps some kind of paste around the trunk to prevent ants from climbing, but with our daily rains that might wash off too fast to be reliable, and I'm worried about causing rot. That was my first idea to investigate, anyhow.

Are there natural systemics for what you suggest? I'm trying to avoid using exotic chemicals on anything except roaches and termites. Citrus trees are so tough and well suited to the local climate it doesn't seem necessary to get too extreme.

Kumquat is not in the ground yet. Here are the other two.

Yuzu:

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Honey tangerine:

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This post was edited by bkrownd on Sat, Jun 7, 14 at 17:11

Old lemon-orange tree. Fairly sour and faintly unpleasant flavor. (may be over-ripe) A specific variety, or perhaps just a mongrel?

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This post was edited by bkrownd on Sat, Jun 7, 14 at 17:26

I might have to use a seriously nasty systemic for my clermontia shrub, though, because the mites are obliterating it and neither the safer soap or neem is effecting them.

bk... looks like a Meyer lemon to me; definitely not an orange judging by the leaf; maybe if you stop thinking of it as an orange and start thinking of it as a lemon, you will be happier.

This post was edited by Johnmerr on Sun, Jun 8, 14 at 22:01

Thanks! I'll check whether the unusual component of the flavor is consistent with meyer lemon, or if it's just this tree.