Avacado Tree /Shot hole borer

[Kathy446]

Hello......
I live in Whittier California and I have an avocado tree that's over 20 years old. We had avocados every year except for last year. I noticed the leaves were dying and spotted some white fungus on the tree branches. I had someone take a look at the tree and was told it looks like the shot hole borer is attacking my tree. We had the tree injected, I'm not sure what it was injected with, but it worked. My tree looks healthy again, new leaves have grown and a whole bunch of avocados are growing on the tree.
Because the tree was injected "Does that mean we can"t eat the avocados? If the avocados should not be eaten and someone does eat one, how will it affect their health? Thank you

 

[jefflovstrom]

Hi Kathy, hope this helps,
http://www.ucanr.org/blogs/blogcore/postdetail.cfm?postnum=24338

Jeff

 

[JeffGu]

You would need to ask the contractor who treated the tree which systemic pesticide and fungicide was used.

If we assumed the pesticide was imidacloprid, there are formulations for trees with edible fruits, that have a lower concentration of the pesticide. Keep in mind that this systemic pesticide does not show up in the flowers and fruit in concentrations sufficient to control pests, and is intended to treat pest affecting the leaves and stems of plants. The formulations for edible crops usually list a harvest waiting period, depending on species... it varies from about a week to about a month and a half. If imidacloprid was used, then you could safely harvest anytime after about two months since the injections, as the fruit wouldn't contain harmful levels, if any, of the pesticide.

Other systemic pesticides used on edible crops have a similar labeling and usage scheme, but you would have to know the particular pesticide and the pre-harvest intervals that are recommended for that product.

 

[Jed1124]

Hello......
I live in Whittier California and I have an avocado tree that's over 20 years old. We had avocados every year except for last year. I noticed the leaves were dying and spotted some white fungus on the tree branches. I had someone take a look at the tree and was told it looks like the shot hole borer is attacking my tree. We had the tree injected, I'm not sure what it was injected with, but it worked. My tree looks healthy again, new leaves have grown and a whole bunch of avocados are growing on the tree.
Because the tree was injected "Does that mean we can"t eat the avocados? If the avocados should not be eaten and someone does eat one, how will it affect their health? Thank you

Do you have the contract from the person who injected the tree? That should state what it was injected with. Otherwise call them and ask. They should have a record of what was used and the date it was used on. Let us know what you hear from them or your contract.

 

[Jed1124]

You would need to ask the contractor who treated the tree which systemic pesticide and fungicide was used.

If we assumed the pesticide was imidacloprid, there are formulations for trees with edible fruits, that have a lower concentration of the pesticide. Keep in mind that this systemic pesticide does not show up in the flowers and fruit in concentrations sufficient to control pests, and is intended to treat pest affecting the leaves and stems of plants. The formulations for edible crops usually list a harvest waiting period, depending on species... it varies from about a week to about a month and a half. If imidacloprid was used, then you could safely harvest anytime after about two months since the injections, as the fruit wouldn't contain harmful levels, if any, of the pesticide.

Other systemic pesticides used on edible crops have a similar labeling and usage scheme, but you would have to know the particular pesticide and the pre-harvest intervals that are recommended for that product.

I don't know of any trunk injected Imadacloprid that is labeled for edibles. I don't know them all but that is news to me. I see the homeowner stuff in the hardware store but I have not on the stuff we use in the industry. Residuals can be as long as 3-5 years for imidacloprid on some trees.

 

[JeffGu]

I don't know of any trunk injected Imadacloprid that is labeled for edibles.

You're probably correct... I believe the imidacloprid formulations for edibles are usually root wash, with low concentration of the pesticide. I probably should have used a different example.
But, we don't know what was used, or even if the contractor was aware that the avacados were for human consumption... so, we still need to know what was used. Residuals for the pesticide in the flowers and fruit are always a lot lower, but any injectable suitable for edible fruit/nut trees should have the pre-harvest interval listed. That's also useful information for determining the risk to bees... if the treatment is done at least as long as the interval before flowering, you lower the risk of killing important pollinators.

Here, in the temperate zone, I tell folks not to eat any fruit from the trees during the year the treatment was done. The exception would be the aforementioned, low concentration root wash formulations, which I use on my own fruit trees on occasion. If treated well before flowering, those are safe... but they always have the pre-harvest interval listed for various species (the list is quite long), as well, in the product documentation.

I'm rather surprised that the contractor didn't discuss any of this with the homeowner, prior to treatment.

 

[Jason Douglas]

Commercial imida products with residential labeling dont have fruit tree harvest intervals for root soaks/soil injections as the product isnt intended for it. I bet it says somewhere in the fine print about no feed/food/forage for 12 months after treatment. There may be an orchard-only product that allows a root soak but I doubt it. We once treated a bunch of apples for San Jose scale with Safari soak and multiple crawler sprays and I only agreed to the work if they were marked and taken out of fruit production for 12 months. Work on fruit trees is a PIA.

Since the avocado had bark beetles, em ben was probably used rather than imid and the residual can be for some time.

Gotta ask the applicator what they used and they'll have to talk to the manufacturer about residual in the fruit.

 

[Kathy446]

You would need to ask the contractor who treated the tree which systemic pesticide and fungicide was used.

If we assumed the pesticide was imidacloprid, there are formulations for trees with edible fruits, that have a lower concentration of the pesticide. Keep in mind that this systemic pesticide does not show up in the flowers and fruit in concentrations sufficient to control pests, and is intended to treat pest affecting the leaves and stems of plants. The formulations for edible crops usually list a harvest waiting period, depending on species... it varies from about a week to about a month and a half. If imidacloprid was used, then you could safely harvest anytime after about two months since the injections, as the fruit wouldn't contain harmful levels, if any, of the pesticide.

Other systemic pesticides used on edible crops have a similar labeling and usage scheme, but you would have to know the particular pesticide and the pre-harvest intervals that are recommended for that product.

You would need to ask the contractor who treated the tree which systemic pesticide and fungicide was used.

If we assumed the pesticide was imidacloprid, there are formulations for trees with edible fruits, that have a lower concentration of the pesticide. Keep in mind that this systemic pesticide does not show up in the flowers and fruit in concentrations sufficient to control pests, and is intended to treat pest affecting the leaves and stems of plants. The formulations for edible crops usually list a harvest waiting period, depending on species... it varies from about a week to about a month and a half. If imidacloprid was used, then you could safely harvest anytime after about two months since the injections, as the fruit wouldn't contain harmful levels, if any, of the pesticide.

Other systemic pesticides used on edible crops have a similar labeling and usage scheme, but you would have to know the particular pesticide and the pre-harvest intervals that are recommended for that product.

I misplaced the invoice for the tree service, and the contractor is on vacation. But I did find an email from the contractor stating that he was going to use Merit. Once the contractor is is back I will update my post with more information. Thank you

 

[JeffGu]

Merit is an imidacloprid product, usually at 75% concentration and mixed with water as a soil drench when used on trees. I'm thinking you might not want to eat the avocados until you talk to the contractor. I wasn't aware in was injectable, but I don't do injections. Jason probably knows. That's probably going to be a high concentration of the pesticide. I use Bayer's Fruit, Citrus & Vegetable on my fruit trees... but it's only about .2% concentration, and I dilute it down. I've only used that high-powered Merit on highly infested ornamental trees.

 

[Kathy446]

The tree is close to the wall and anyone passing by can easily pick the avocados off the tree and I'm worried that they will get sick. Im am going to have put a warning sign to let the public be aware not to eat the avocados.

 

[JeffGu]

Good thinking, Kathy.

 

[ATH]

Find out what rate it was applied. You can water it down quite a bit. There are several different formulations...

Here is the label for the only "Merit" injectable that I know of. Specifically says NOT to use on fruit or nut trees.

Merit 2F label (linked here) DOES say it can be used on fruit and nut trees, but not commercial.

We are back to: what was used? There are other injectable imidacloprid formulations. Merit is the 'brand name" imidacloprid, but it is off patent now, so there are dozens and dozens of other brands. Did he really use Merit, or does he call all imidacloprid "Merit" (kinda like calling all tissues "Kleenex"...)

 

[beastmaster]

Im really suprised that a drench or injectable worked on the shot hole borer. I removed over a 100 high value trees at the santa ana botanical gardens in Clairmont(L.A.)that were devastated by this pest. They bore deep into the wood in effect making it like balsa wood. Their entry holes are not round but half round, flat on other side. Vary Unique.
I am Suspicious of a lot of companys that diagnose and treat trees. But its great if merit will stop this pest.

 

[Jason Douglas]

It's not labeled for bark beetles.