Best product for Phomopsis?

[simon_grow]

Hello everyone,

I've been paying really close attention to my trees, and others, over the last several years and I'm starting to notice that we have a lot more fungal issues with Mango than I originally thought. The minor issues with powdery mildew and Anthracnose on fruit is no biggie but we seriously have an issue with Phomopsis.

The only real way to confirm you have Phomopsis is to send out samples to a lab, I used to run such samples but not anymore, but I have not sent out any samples so I'm only speculating. But, I do have a friend that did send out samples and it was confirmed as Phomopsis. I just want to mention that I've been doing a lot of reading on Mango diseases and there are many, many different types of fungal issues that can plague our trees, Phomopsis is just one that I know is confirmed.

In reality, what affects our trees specifically here in SoCal can be any number of fungal or bacterial diseases but from observations from many different orchards around the San Diego area, it is safe to say that many of our sick trees are affected with a type of fungal disease.

I was wondering what the latest consensus is as to the best treatment for fungal diseases, especially for Phomopsis.  I've already searched the forum and read all the threads by Cookie Monster, Mark and others but I'm looking for the best latest information. Things may have changed in half a year.

I know Mark in Texas was an advocate for Phyton35 and others have recommended Abound. I want to find something that is effective that anyone from this forum can just order off the internet. If it is a available in small quantities, even better.

The fungal diseases appear to be affecting smaller trees much more than larger fully established trees. I still believe that sharpshooters are the major vector for disease around much of SoCal.

Simon

[simon_grow]

Phyton35
http://tropicalfruitforum.com/index.php?topic=19877.msg245868#msg245868
Sharpshooters
http://tropicalfruitforum.com/index.php?topic=20756.msg255292#msg255292
Copper Fungicides
http://tropicalfruitforum.com/index.php?topic=19460.0
Simon

[behlgarden]

I have Phomopsis on most trees, here or there. I sprayed with Abound and boron, with not much success. best bet is to cut the infected limbs off. Per Peter sometimes trees grow out of it.

[simon_grow]

Thanks for the report Behl,

After a bit of research, information I gathered from friends in the mango growing community suggest that ensuring our trees have enough Manganese may help with Phomopsis. A friend that has contacted Dr Crane said that Azoxystrobin can help fight Phomopsis. I'm going to try Abound and increase Manganese and magnesium.

I wonder if anyone has noticed any patterns of infection or non infection?

For examples, I have noticed that seedling trees seem less susceptible to die back. Grafted trees seem more prone to die back except that certain varieties like Valencia Pride seem less prone to the die back. I wonder if certain compounds in the sap of specific varieties might offer some resistance. Or Perhaps certain varieties are just more vigorous and able to outgrow the infection?

Simon

[Mark in Texas]

Dithane or any mancozeb product.  No resistance issues, very broad disease control and if it contains a surfactant is rainfast.  Is a broad spectrum contact fungicide vs systemic like the copper pentahydrate products - Magna Bon or Phyton.  You must agitate constantly while spraying and I run mine thru a coarse sieve as I pour into the tank.   http://www.dowagro.com/en-us/usag/product-solution-finder/fungicides/dithanef45

[simon_grow]

Thanks for the information Mark! I'll look more into those products. I have a friend that is going to send me some small samples of Abound. One major issue with these fungicides is that they are very expensive and the quantities they are sold in will last the typical backyard gardener 10 lifetimes if not more. The mango growing community here may want to do a group buy and then split up the bottle into more manageable quantities that are more reasonably priced.

Simon

[GrassFlats]

That is a good idea simon....a forum member recently helped me out with some fungicide that costs an arm and a leg if buying the entire container/bag

[palmcity]

Thanks for the information Mark! I'll look more into those products. I have a friend that is going to send me some small samples of Abound. One major issue with these fungicides is that they are very expensive and the quantities they are sold in will last the typical backyard gardener 10 lifetimes if not more. The mango growing community here may want to do a group buy and then split up the bottle into more manageable quantities that are more reasonably priced.

Simon

Dithane or any mancozeb product.  No resistance issues, very broad disease control and if it contains a surfactant is rainfast.  Is a broad spectrum contact fungicide vs systemic like the copper pentahydrate products - Magna Bon or Phyton.  You must agitate constantly while spraying and I run mine thru a coarse sieve as I pour into the tank.   http://www.dowagro.com/en-us/usag/product-solution-finder/fungicides/dithanef45

I wanted to wait to see if anyone mentioned mancozeb as the chart I found does not list mangos.
Marks Texas Wine Grape State does have a nice chart on fungicides. Especially phomopsis and anthracnose in last 2 columns.
http://winegrapes.tamu.edu/grape-growing/diseases-pests-problems/grape-disease-management/black-rot/efficacy-of-fungicides-for-the-control-of-grape-diseases/

Efficacy of Fungicides for the Control of GRAPE Diseases
Fungicide (tradename)   Black Rot1   Downy Mildew1   Powdery Mildew1   Phomopsis Cane and Leaf Spot1   Anthracnose
azoxystrobin (Abound)2,3   +++   +++ (FRP)   +++ (FRP)   +   ?
boscalid (Endura)   0   0   +++   0   ?
boscalid + pyraclostrobin (Pristine)3   +++   +++ (FRP)   +++   ++   ?
captan (Captan, Captec)   +   +++   0   +++   +
cyprodinil (Vangard)   0   0   0   0   ?
fenarimol (Rubigan)2   ++   0   +++ (FRP)   0   ?
fenhexamid (Elevate)   0   0   0   0   ?
ferbam (Carbamate)   +++   +   0   +   ?
fixed Copper and lime   +   +++   ++   +   +
iprodione (Rovral)   0   0   0   0   ?
kresoxim-methyl (Sovran)2,3   +++   ++ (FRP)   +++ (FRP)   +   ?
mancozeb (Dithane, Mancozeb, Manzate)   +++   +++   0   +++   +
metalaxyl (Ridomil GoldMZ)   ++   +++   0   +   0
metalaxyl (Ridomil Gold Copper)   +   +++   ++   +   0
myclobutanil (Nova)2   +++   0   +++ (FRP)   0   ?
phosphorous acid (various formulations)   0   +++   0   0   0
potassium salts (Armicarb 100, Kaligreen)   0   0   ++   0   –
pyrimethanil (Scala)   0   0   0   0   ?
quinoxyfen (Quintec)   0   0   +++   0   0
Stylet oil (JMS)   0   0   +++   0   0
Sulfur (several formulations)   0   0   +++   +   ?
tebuconazole (Elite)2   +++   0   +++ (FRP)   0   ?
thiophanate-methyl (Topsin M)4   +   0   +++   ++   ?
trifloxystrobin (Flint)2,3   +++   + (FRP)   +++ (FRP)   +   ?
tebuconazole + trifloxystrobin (Adament)   +++   +   +++   +   ?
triflumizole (Procure)2   ++   0   +++ (FRP)   0   ?
Ziram   +++   ++   0   ++   +
Lime sulfur (Calcium Polysulfide)
dormant spray   –   –   –   –   ++
Key: +++ = highly effective; ++ = moderately effective; + = slightly effective; 0 = not effective ? = effectiveness unknown or not established; FRP=Fungicide Resistance Possible
1Source: Midwest Commercial Small Fruit and Grape Spray Guide 2008
2These fungicides are not recommended for powdery mildew control due to the development of funigicide-resistant strains of the powdery mildew fungus.
3These fungicides are not recommended for downy mildew control due to the development of funigicide-resistant strains of the downy mildew fungus.
4Where Topsin M-resistant strains of the powdery mildew and Botrytis fungi have been detected, Topsin M will be ineffective and should not be used.

[fruitlovers]

What do affected limbs look like? Do you have a photo?

[Mark in Texas]

I wanted to wait to see if anyone mentioned mancozeb as the chart I found does not list mangos.

That's because the target is grapes.  Doesn't mean it won't work well on mangos and isn't safe.  This labeling biz is a bunch of bullshit, expense, that the vendors must submit to for every group of crops. 

Nice job.  Here's a photo of what you presented.  Worth opening! 



For you non commercial guys Captan and mancozeb is your cheapest and most effective solution.  Be sure you use a non-ionic surfactant in your mix or you're spinning your wheels.   Captan can be sprayed up to the day of harvest, at least for grapes which unlike mango are eaten/crushed skin and all.

Good luck!

[simon_grow]

Great discussion everyone! Thanks for all the detailed information.

Oscar, I recently cut away the infected limbs but I'm sure I missed some so I'll take some pictures if I can find some more infected limbs. Small branches typically completely die back and the dead leaves remain on the dead limb without falling off.

Simon

[simon_grow]

Oscar,

Here are a few pictures of some die back. I don't currently have any pictures of the typical die back with the leaves still attached because those branches are easily identifiable and immediately removed. These pictures below show the die back creeping down.

Several months before die back occurs, I notice that there are often times wounds created by sharpshooter insects. First I will notice the bite mark, just a small hole with a bit of wet looking sap. Several weeks later, the wound turns black and get progressively larger. If the bite is on the leaf petiole, sometimes only the leaf will fall off but other times, the dead area enlarges and the whole stem dies back to a collar.









Some of the pictures look very much like typical die back of spent inflorescence except these stems were not floral.

Die back can also be caused by root disturbances.

Simon

[fruitlovers]

Thanks Simon. I think i got that occuring here as well. 

[gozp]

Simon, does drenching epsom salt (high in sulfur) combats any diseases for mangoes or is it any beneficial?

[simon_grow]

In my opinion, Epsom salts are beneficial for many growers here in SoCal because our plants often lack Magnesium or sulfate. Magnesium is to Chlorophyll what Iron is to our Hemoglobin.

If our plants are very healthy, I would assume that it will be much better able to defend itself from diseases or at least it will be healthy enough to overgrow what is dying back.

A friend mentioned that Dr Crane said that Manganese deficiency could open a mango tree up to infection by Phomopsis so in my opinion, we should especially focus on supplementing our trees with Manganese in order to lessen the chances of infection.

I've mentioned this many times before but I'll say it again because there are newer members that may not have read through all my older posts, if your soil or water pH is outside the optimal range for mangos, I highly recommend foliar feeding as opposed to drenches or pelleted fertilizers.

For each major, minor and trace element, there is an optimal pH range where the mango trees roots can readily uptake that element. One element may be more bioavailable between 5.5-6.5 and another element may be more bioavailable between 6.2-7.8. If the pH of your soil is 8.0, your plant will likely show those nutrient deficiencies in short time.

One major problem we have is that many minor and trace element deficiencies look very similar and some gardeners will add too much of the element they thought was deficient only to find out they were wrong so they add too much of the next element they thought was deficient. By adding too much of one element or another, it can cause antagonistic imbalances between the elements or ions in the rhizosphere. Many of us refer to this as nutrient lock.

Because we generally have high pH soil and water here in SoCal, many of the minor and trace elements are not bioavailable. We can make more of the elements bioavailable by bringing down the pH of our soil closer to 6.5 but our plants will still likely need other minors and trace elements that the native soil is lacking.

I recommend that we apply our fertilizers as a foliar spray as the total amount of fertilizer used in foliar spraying is significantly less than that of ground applications and you pretty much eliminate the likelihood of nutrient lock in the rhizosphere.

For the drip zone of our trees, I highly recommend a good layer of compost followed by a nice layer of mulch. This will create a nice microclimate for earthworms and micro organisms. These bugs along with bacteria and fungi in turn release waste that is fertilizer for our trees that may be more bioavailable because they act as a mixture of cations and anions that can be exchanged at the soil root interface.

Simon

[simon_grow]

Simon, does drenching epsom salt (high in sulfur) combats any diseases for mangoes or is it any beneficial?

gozp, Magnesium Sulfate is a bit different than Sulfur. Sulfate is bioavailable to plants and is considered(generally) as non acidifying. Sulfur is not bioavailable to plants until it gets oxidized and elemental sulfur is highly acidifying. Microorganisms in soil can oxidize sulfur into sulfuric acid which is highly acidic.

Sorry for going off on the long tangent but yes, Epsom salts are good but I don't know of any particular diseases that adding Epsom salts can ward off. I mentioned above that I recommend foliar feeding for most our mango trees elemental needs but Epsom Salts are one of the fertilizers I still do apply on the ground.

Simon

[fruitlovers]

Does lime (calcium) help to ward off fungal diseases in mango? Is it better to use dolomite for this purpse, Ca+Mg?

[Mark in Texas]

What do affected limbs look like? Do you have a photo?

Black splotches or streaks.

[Mark in Texas]

Does lime (calcium) help to ward off fungal diseases in mango? Is it better to use dolomite for this purpse, Ca+Mg?

Not straight lime.  Maybe Bordeaux mix which contains lime to offset the acidity of copper sulfate.

http://ipm.ucanr.edu/PMG/PESTNOTES/pn7481.html

But, if you're going to go thru the hassle of mixing a copper spray might as well have the convenience and far superior control of copper pentahydrate products.

[simon_grow]

I would use a product especially formulated to prevent mango diseases. I don't know if lime or Dolomite by itself, used as a foliar or ground application would do anything to prevent disease, I don't recall coming across any articles in this regards. I do know that lime and Dolomite can raise soil pH which can be good or bad depending on the current pH of your soil.

As a wholistic approach, I personally use baking soda and water to prevent mold/fungus from growing on my indoor wheatgrass. I wonder if anyone has tried this to prevent Powdery mildew on mango inflorescences?

Simon

[wslau]

I would use a product especially formulated to prevent mango diseases. I don't know if lime or Dolomite by itself, used as a foliar or ground application would do anything to prevent disease, I don't recall coming across any articles in this regards. I do know that lime and Dolomite can raise soil pH which can be good or bad depending on the current pH of your soil.

As a wholistic approach, I personally use baking soda and water to prevent mold/fungus from growing on my indoor wheatgrass. I wonder if anyone has tried this to prevent Powdery mildew on mango inflorescences?

Simon

Simon...
Posted on other thread (pg 32)
http://tropicalfruitforum.com/index.php?topic=1001.775

[simon_grow]

Thanks Warren, I just read the article. I can't believe it's not allowed to be used in some places simply because baking soda is not labeled as a fungicide.

Simon

[Mark in Texas]

Thanks Warren, I just read the article. I can't believe it's not allowed to be used in some places simply because baking soda is not labeled as a fungicide.

Simon

That's the way this EPA controlled game is played out.  Much of it may stand to reason, the rest is just plain stupid.

BTW on dithane there is a long window between application and harvest, something like 76 days.

[BestDay]

I'm having horrible Phomopsis problems on my Dot mango.  It has almost killed the small tree back to a stump.  I went to Orange County Farm supply and their pesticide guru recommended Monterey Complete Disease Control with an active ingredient of bacillus Amyloliquefaciens.  He says it is a beneficial Bacteria that outcompetes most harmful bacteria and Fungi such as Phomopsis and Powdery Mildew.  Since it is a bacteria you only have to use it as a drench once to get it into your soil.  As a foliar you need to spray it every two weeks.  Has anyone tried this?  It sounds too good to be true.

Bill

[DesertDreamer]

Phyton 35, mancozeb, in rotation seems to have saved a 'fruit punch' in my yard.  No way a. Liquifaciens is going to cure.