Sharpshooters major vector for disease in Mangos in California?

[simon_grow]

We know that Phomopsis is present in California and I've been noticing an explosion in the number of sharpshooter bugs that suck juice from our Mango trees. I've watched them feed and noticed that the area where they feed usually turns dark and sap usually flows out from the wound after several days to a couple weeks and the injury sometimes turns dark and sometimes the injury will heal. I've noticed that in some cases, the entire young stem will die back. I'm actually surprised that nobody else in California is noticing these bugs that scoot from side to side on their trees.

There are already several threads for fungicides but I'm especially interested in a systemic fungicide that someone can recommend for California although I am extremely interested in opinions from Florida and other areas as to why I might want to use something else.

Previous threads mentioned that Azoxystrobin is the best active ingredient to combat Phomopsis here in California and products like Abound, Quadris and Prestine are perhaps the best of the best.

I try to grow all my plants with no pesticides and fungicides but I would like to perform a few experiments where I treat several young trees with a systemic fungicide to see if preventive applications of fungicide, even before I see any signs of disease, could increase the rate of growth of mangos.  I will not allow these trees to hold fruit for at least 3-4 years and I intend to stop the use of the systemic fungicide 1 year before I intend to allow the trees to hold fruit.

I believe that sharpshooters are the primary vectors for disease here in California and the diseases that they can spread, mainly Phomopsis, can greatly inhibit the growth of young, unestablished Mango trees here. By using a systemic and preventing disease before the tree is infected, I hope to greatly accelerate the establishment of young trees.

All three of these systemic fungicides are extremely expensive, is there something cheaper that may work as well? Are there smaller sizes available? I've searched the web but I can't find small size bottles? Perhaps there is a generic that works equally well?

If there are other solutions that may work, I'd love to hear your ideas and suggestions. Thanks in advance!

Simon

[simon_grow]

Let's not forget that many of our favorite varieties of mangos come to us via plants or scions from Florida and there are reported cases of Botryosphaeria Dieback(thanks Bsbullie)  http://postimg.cc/image/xrqdbc58l/ a fungus which can lay dormant until the tree is stressed. Most of us here in California have experienced dieback at one point or another but let's remember that Mango can be affected by any number of diseases which often have similar indications but from my experience as a microbiologist, we cannot positively ID a disease or pathogen without DNA or cultured identification.

If an orchard has 100 trees all showing the exact same symptoms and DNA results from 99 of those trees come back as disease X, that does not guarantee the 100th tree has the same disease X. With this disclaimer in mind, we can oftentimes narrow down the pathogen and determine wether it is bacterial or Fungal in nature, viruses may be more difficult to ID as they may exhibit various symptoms.

Mark also recommended Magnabon or Phyton 35 as a systemic Bactericide/Fungicide, maybe it's better to prevent both?

Here are several threads that discussed fungicides for mangos.
http://tropicalfruitforum.com/index.php?topic=19460.msg241526#msg241526
http://tropicalfruitforum.com/index.php?topic=1001.msg224776#msg224776
http://tropicalfruitforum.com/index.php?topic=15673.msg253878#msg253878
http://tropicalfruitforum.com/index.php?topic=20070.msg248415#msg248415

Simon

[bsbullie]

Simon - the dieback I posted about is not that common throughout nor us it rampant.  As a matter of fact, I have personally only seen it affecting PPK/Lemon Meringue and have also seen it controlled with fungicides and follow up care.

[simon_grow]

Thanks for the report Rob! I'll keep that in mind. I really wanted to point out that there are any number of Mango diseases out there.

I'm really wondering how much fungal diseases inhibit the growth and establishment of young trees here so I hope I can run a few experiments to see if I notice significant differences in growth between treated and untreated trees. Some rootstocks show significant disease resistance, or at least they are not showing obvious symptoms, whereas other rootstocks are completely stunted.

Simon

[Nisp66]

I had seen lots of these bugs chillin on the branches and did not know what they were or did. The fight begins.
Thanks Simon

Raul

[JF]

Thanks Simon for putting this together and Rob for the clarification.

[knlim000]

Simon,
I don't know if mine are caused by sharpshooters as I do not see the critters on some trees, and these some trees exhibit the sympton you described.  The sap oozing out and the wound gets bigger and bigger.

So for the last week, I have been using tea tree oil on the places that has the wound. I use cottons to rub it.  Amazingly, I think it works like a wonder. It doesn't harm the tree. As a matter of fact, the wounded area starts to form thick scab, bulging out like us human. So now, I start applying the oil to any places that has sap oozing out or little cuts on the tree.

Here's pictures of the after applying the oil, no before pictures. 

[knlim000]

As you can see, I lost about one side of the lower trunk on this Mahachanok.  I don't remember how it had happened. The fungus ate about half of the trunk.  I applied the tea tree oil to try to stop further damage.  I can see the two veins on the trunk exposed.  I cut the top branch off (hence the new flushes ontop) and bind the cutted branch onto the exposed trunk and tape it up with parafilm.  I will need to check if branch  will fused onto the trunk, it's worth a try.  Definelty not sharpshooters. I think it might have been that I wrapped it with bubble wrap last oct & nov and some how the fungus formed inside the moisture? When I open up the bubble wrap in December, I can see that the trunk was shriveling.  I wished I had applied the tea tree oil sooner.

[simon_grow]

You're welcome Raul and JF. Knlimooo, some of the pictures you posted are definitely sharpshooter damage and it does appear that some of the wounds got infected with fungus, primarily the wounds that turn dark.

I was going to post some pictures of sharpshooter damage and progression of wounds but I can't seem to be able to post pictures at the moment.

Anyways, this is exactly what I'm talking about. I believe that sharpshooters are a major vector for disease in mangos and we have to be proactive in this fight.

I'm still trying to narrow down which systemic fungicide to use.

Simon

[marklee]

Simon,

As far as I know when I worked for the County Ag dept. we were only looking for the "GlassyWinged sharpshooter" it may be carrying the
 bacteria X. Fastidiosa or "PIerces disease in grapes, and causes types of leaf scorch, in Oleander, Peaches  and other plants,
You may be seeing the "Smokey Brown" sharpshooter. I have not read anywhere that mangoes are a plant that is harmed  by the sharpshooter.

[Mark in Texas]

All three of these systemic fungicides are extremely expensive, is there something cheaper that may work as well? Are there smaller sizes available? I've searched the web but I can't find small size bottles? Perhaps there is a generic that works equally well?

If there are other solutions that may work, I'd love to hear your ideas and suggestions. Thanks in advance!

Simon

Magnabon is reasonable and it's OMRI certified FWIW.

Attached page 1 of 2 recommended fungicides for Texas vineyards. Dithane, a topical mancozeb type product would be a good choice for phomopsis control and is what many use here during the spring rainy season, which has "killed" us Texas vineyard managers this year.  Being that all are "food grade" they should be safe to use as directed. As noted in the chart do not apply Dithane within 66 days of harvest.   ++++ = most effective; 0 = none



Just got a comprehensive disease bulletin in from Agrilife and here's a part ALL should heed about losing resistance by applying strobies at the wrong time.

Some strobilurins are more effective against downy than others, so check an efficacy chart before making the decision on which to use. With downy as well as powdery mildew, the very worst thing a grower can do is to apply a strobilurin material on top of an ac-tive infection. This is asking for trouble by creating the ideal environment for resistance to occur. With these materials, resistance is controlled by a single gene, and when resistance is formed, they quit working all together. When that happens a grower typically applies the material then finds out two weeks later that they have a disaster on their hands. Phos-acid materials such as Prophyte, Phostrol, Rampart, etc. provide growers with an excellent post-infection and rescue treatment, but they provide little forward protection.

Imidacloprid aka Adonis 75WSP will control sharpshooters.  In fact once applied it repels them.  It has saved the Texas wine industry from the deadly Pierce's Disease epidemic years ago.  PD is pretty much a thing of the past, thank God.

Mark

[simon_grow]

Thanks for the information Mark! That brings up an even more important point, we need to create a well planned schedule were we switch fungicides on a rotating schedule so that the pathogens don't build up resistance. Improper use of these chemicals can be detrimental in the long run if not utilized correctly.

Another point to consider is wether or not to just target the sharpshooters themselves instead of the diseases which I presume them to carry, and it is only my presumption.

I need to think about this some more before I cause more harm than good.

Simon

[raimeiken]

wow I never even thought of those bugs doing damage. I see them all the time on my mango trees only, around the newer branches.

[knlim000]

So I unwrap the prarafilm, BIG mistake!!!  I should not have wrap the cutted branch with the trunk. It was all moldy  and I went thru about 10 cottonswaps cleaning it with tea tree oil.  I love this oil.  It seals up the wound very quick , a day or two. 

This is not the doing of sharp shooter.  For some reason, the bark shrivel up (maybe from the bubble wrap causing condensation).

[simon_grow]

That recent pic isn't sharpshooter damage but the second picture you posted appears identical to a picture I have of sharpshooter damage. They suck on newer younger green growth. Try some copper fungicide, it works really well.

Simon

[knlim000]

I see great and fast result with tea tree oil in a day or two. Does the cooper fungicide work fast?

[simon_grow]

Copper works great and the soap spray forms breaks the surface tension for better penetration. I use copper soap sprays for my scions before I wrap them with parafilm so they don't get moldy.

Simon

[simon_grow]

Early Sharpshooter damage, I literally watched as the bug raised his butt in the air while sucking juice and peeing out his butt at the same time. This is 2-3 weeks after initial damage.

Here is a healed, lignified wound

Wound with potential fungal infection


Wound which initially turned black and now has died back



Here is a picture of the bug in question

We need to stop this bug, it sucks on plant juices from multiple varieties of trees and i just hope it's not a vector for HLB in citrus

Simon

[Mark in Texas]

I see great and fast result with tea tree oil in a day or two. Does the cooper fungicide work fast?

As a curative?  Only if it's systemic which leaves you two copper products - Phyton 35 and Magabon. Topical coppers such as Kocide are useless once you have a problem.

[OCchris1]

I feel your pain Simon. I have smashed quite a few sharpshooters in my yard but never equated the insect with the branch dieback i have experienced until now. Makes perfect sense and now its game ON. Chris