Durian leaf antracnose

[Klong Song]

I planted a durian tree a few months ago and it developed brown to black areas beginning at the tip and edges of the leaves (see attached image). A google search makes me think that it is probably leaf antracnose. I went to my local shops in Talad Thai and they sold me a fungicide that they said would clear it up (see attached image). I have sprayed about three times with about a week between applications but I am seeing little improvement if any. I am hoping someone here has some experience with this disease and can offer some suggestions. Thanks

 

 

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[anon2736434]

http://animhosnan.blogspot.com/2013/12/durian-foliar-diseases.html

http://durianinfo.blogspot.com/p/durian-pests-and-diseases.html

[CLW]

First you should remove all infected leaves and dispose them properly.
The fungicide you have is often no longer effective because there are resistances.
You could use mancozeb instead.
I am not sure if there are systemic fungicides available.

[Klong Song]

First you should remove all infected leaves and dispose them properly.
The fungicide you have is often no longer effective because there are resistances.
You could use mancozeb instead.
I am not sure if there are systemic fungicides available.

Thanks for your help, I’ll give it a try.


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[Thian]

My durian also had leaves like that in the past, i always thought it was fertilizer burn or so...it also disappeared by itself...Durian is the only tree in my garden which never has issues, no insects eat it.

 

The ony spray my durian gets is seaweedextract or chemical micronutrients. It always looked healthy to me and gave it's first fruit this year.

[drtreelove]

It sure appears to be a fungal leaf spot and maybe an anthracnose, there are several possible causal organisms.

 

A common mistake is to think that the application of a fungicide will clear up fungal leaf spots or anthracnose type infections. But from my experience, the affected foliage will never be "cured" and clear the necrotic tissue and return that affected leaf or leaves to a normal state, no matter what you spray or inject.  

What you can hope for with a a fungicide application is to suppress the advance of the infection and stop the spread to healthy tissue.  The more advanced the existing infection is in the plant, the harder that is to achieve.

 

Prevention, early intervention is possible to get results of suppression, but cure of an advanced infection is difficult or impossible depending on what the pathogen is and what chemistry you have available for treatment.  (Not all fungicides will suppress all fungi. 

and like CLW points out, chemical fungicides are subject to diseases acquiring resistance to the class of fungicide used. And often, chemical fungicides sprayed on foliage will suppress beneficial fungi and bacteria that work as natural biological controls against pathogenic fungi.

 

That could be why Thian's approach is sound, to build plant health and provide nourishment through soil improvement and foliar nutrient applications which help the plant build resistance on it's own and with the help of naturally occuring beneficial biology. 

You can assist that beneficial biology, in the soil and on the foliage, by first not killing it off. And second, by recognizing the seasonal climate related disease cycles, like wet season and fungal leaf disease, and taking a preventive step by applying a concentrated biological fungicide, maybe along with your foliar fertilizing tank mix.  A good quality EM is one type of biofungicide product, Trichoderma is another. Biofungides are not subject to the same type of resistance. 

It's probably too late in the season and in the disease cycle to expect much results for your durian anthracnose now, but consider a preventive program starting now with soil fertility and a spray program for next year. 

 

 

[JungleBiker]

The same fungus (Colletotrichum gloeosporoides) that causes anthracnose in durian also causes anthracnose in avocado, and the fungicides used for avocado are:

 

(a) Copper-based fungicides - they are protective not curative, and can be used by organic growers; and

 

(b) Amistar (active ingredient: azoxystrobin) which is systemic and has partial curative properaties but should not be sprayed too many times per season. Amistar is made by Syngenta. There are other brands of azoxystrobin that are cheaper. 

 

All of the above are easy to find in Thai agrochemical shops. 

 

 

 

 

[Klong Song]

I was hoping you guys would ring in on this because you always have very informative posts. The disease has spread to a majority of the leaves now but as they fall off there is new growth that soon appears. I am trying to keep the new growth healthy. I will follow the suggestions given here and see if things improve.

 

As an aside for the dr, I think I saw in one of your previous posts that you have spent some time in Santa Cruz, CA. I lived in the county from 1975-1990, from Boulder Creek to Aptos and points in between. Great place to live.

 

Thanks for your advice on this problem.

 

 

 

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[CLW]

The same fungus (Colletotrichum gloeosporoides) that causes anthracnose in durian also causes anthracnose in avocado, and the fungicides used for avocado are:
 
(a) Copper-based fungicides - they are protective not curative, and can be used by organic growers; and
 
(b) Amistar (active ingredient: azoxystrobin) which is systemic and has partial curative properaties but should not be sprayed too many times per season. Amistar is made by Syngenta. There are other brands of azoxystrobin that are cheaper. 
 
All of the above are easy to find in Thai agrochemical shops. 
 
 
 
 

I was always thinking that Azoxystrobin was an antibiotic.
I read more about it and found out that it is a engineered compound after some natural occurring fungi.
It is classified as a low toxic fungicide and will degrade in the soil after 40 days.
One article just mentioned one should use brand name formulations because generics are sometimes polluted with toluol.

[Klong Song]

Would one of you please recommend a foliar feeding product. Thanks


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[CLW]

Would one of you please recommend a foliar feeding product. Thanks


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Do you mean foliar fertiliser / plant strengthening product?

[Klong Song]

Do you mean foliar fertiliser / plant strengthening product?

Yes


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[drtreelove]

On 10/22/2018 at 8:07 PM, JungleBiker said:

The same fungus (Colletotrichum gloeosporoides) that causes anthracnose in durian also causes anthracnose in avocado, and the fungicides used for avocado are:

 

(a) Copper-based fungicides - they are protective not curative, and can be used by organic growers; and

 

(b) Amistar (active ingredient: azoxystrobin) which is systemic and has partial curative properaties but should not be sprayed too many times per season. Amistar is made by Syngenta. There are other brands of azoxystrobin that are cheaper. 

 

All of the above are easy to find in Thai agrochemical shops. 

 

 

 

 

 

On 10/22/2018 at 8:26 PM, Klong Song said:

As an aside for the dr, I think I saw in one of your previous posts that you have spent some time in Santa Cruz, CA. I lived in the county from 1975-1990, from Boulder Creek to Aptos and points in between. Great place to live.

Now you're making me homesick for the fresh clean air off the Pacific ocean and the cool fragrant redwood forest.  Yes I lived and worked in Santa Cruz since 1975 also, when I moved from Arizona to Boulder Creek. I was 20 something, making $3.50 an hour as a tree worker in Phoenix and I was sick of climbing palms and thorny mesquites and palo verdes in the desert heat.  I heard that I could make $5 or 6 an hour in California. So I packed up my dog and climbing gear and a few belongings in my pickup and headed out to LA and up the Big Sur coast.  I had a girlfriend in BC and a place to stay; got hired by Davey Tree the day after I arrived and was hiking up big redwoods, firs and oaks by the following Monday. It's an amazingly beautiful, bountiful, culturally diverse and prosperous region. The trees are really incredible and gave me an outdoor athletic life and health, and a 40+ year career. 

 

 

 

[Klong Song]

Now you're making me homesick for the fresh clean air off the Pacific ocean and the cool fragrant redwood forest.  Yes I lived and worked in Santa Cruz since 1975 also, when I moved from Arizona to Boulder Creek. I was 20 something, making $3.50 an hour as a tree worker in Phoenix and I was sick of climbing palms and thorny mesquites and palo verdes in the desert heat.  I heard that I could make $5 or 6 an hour in California. So I packed up my dog and climbing gear and a few belongings in my pickup and headed out to LA and up the Big Sur coast.  I had a girlfriend in BC and a place to stay; got hired by Davey Tree the day after I arrived and was hiking up big redwoods, firs and oaks by the following Monday. It's an amazingly beautiful, bountiful, culturally diverse and prosperous region. The trees are really incredible and gave me an outdoor athletic life and health, and a 40+ year career. 
 
 
 

I was always very appreciative of Davey Tree for keeping Hwy 9 open, always fast and efficient. When I got back to CA after traveling through Central and South America friends said It was happening in SC and I should come up. I wasn’t disappointed, those early days were the best. I started out in Boulder Creek as well. Like a lot of guys I bought a truck and started cutting firewood to make ends meet. Used to work with a friend on Deer Creek road taking downed trees on the uphill side. Hard work but like you say it keeps you outside and in good shape. Did some milling as well, we had Stihl 090’s on each end of a four foot bar. When I go back to CA I always try to fit in a couple of days in SC to see old friends.

Can you suggest a foliar fertilizer for my durian tree? I am always at the mercy of the people in the shops.


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[drtreelove]

On 10/22/2018 at 8:07 PM, JungleBiker said:

The same fungus (Colletotrichum gloeosporoides) that causes anthracnose in durian also causes anthracnose in avocado, and the fungicides used for avocado are:

 

(a) Copper-based fungicides - they are protective not curative, and can be used by organic growers; and

 

(b) Amistar (active ingredient: azoxystrobin) which is systemic and has partial curative properaties but should not be sprayed too many times per season. Amistar is made by Syngenta. There are other brands of azoxystrobin that are cheaper. 

 

All of the above are easy to find in Thai agrochemical shops. 

 

 

 

 

In my opinion, the problem with using broad spectrum chemical fungicides like Amistar, is that you get locked into a vicious cycle of chemical dependency, and along with killing pathogens, may be killing and not cultivating the natural defenses.  And although this chemistry is registered for specific food crops, I try to avoid systemic pesticides for food producing plants

BTW, Copper based fungicides are not all created equal, some are not appropriate for application to foliage and fruits, and for mixing with other chemistry, because of phyto-toxicity.  Best to determine which product is recommended for the target and the host plant and at what period of time in the growing cycle and at what concentration.  

[drtreelove]

17 hours ago, Klong Song said:

I was always very appreciative of Davey Tree for keeping Hwy 9 open, always fast and efficient. When I got back to CA after traveling through Central and South America friends said It was happening in SC and I should come up. I wasn’t disappointed, those early days were the best. I started out in Boulder Creek as well. Like a lot of guys I bought a truck and started cutting firewood to make ends meet. Used to work with a friend on Deer Creek road taking downed trees on the uphill side. Hard work but like you say it keeps you outside and in good shape. Did some milling as well, we had Stihl 090’s on each end of a four foot bar. When I go back to CA I always try to fit in a couple of days in SC to see old friends.

Can you suggest a foliar fertilizer for my durian tree? I am always at the mercy of the people in the shops.


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090, thats a major power-head, How's your hearing? Mine's long gone along with other seriously abused body parts. 

 

I don't know what to recommend for foliar fert here, I have seen liquid kelp and humic acid products, with which you can't go wrong.  Thian or other friends here may offer some suggestions.  I never look at foliar fertilizing as a complete nutrient application, but it can be an important supplement for specific absorbable nutrients.  Not all essential plant nutrients can be absorbed and utilized through foliar applications,  Even the ones that can need to be applied frequently, like weekly, because there such a limited amount of the material that is absorbed with one application.  

I have never found one particular product even in the US.  I did a lot of foliar fertilization for trees an shrubs, but always in combination with soil applied fertilization.   I tank-mixed a solution of high quality chelated micro nutrients and liquid kelp along with a fulvic acid product to facilitate absorption, and compost tea or a biological fungicide product.  I never tried to get macronutrients with foliar, but used soil applications with soil-test based amendments or a complete fertilizer. 

[drtreelove]

1 hour ago, drtreelove said:

In my opinion, the problem with using broad spectrum chemical fungicides like Amistar, is that you get locked into a vicious cycle of chemical dependency, and along with killing pathogens, may be killing and not cultivating the natural defenses.  And although this chemistry is registered for specific food crops, I try to avoid systemic pesticides for food producing plants

 

 

"Farmers are so often locked into an ever-escalating armory of rescue chemicals, in an attempt to maintain yield and profitability. In fact, the global statistics reveal a remarkable trend. Each year, we introduce more chemicals into the equation, and yet every year there is an overall increase in pest and disease pressure. This is actually the definition of “unsustainable”. We can’t keep pouring on more and more, for less and less response."  Graeme Sait

 

[Klong Song]

 
"Farmers are so often locked into an ever-escalating armory of rescue chemicals, in an attempt to maintain yield and profitability. In fact, the global statistics reveal a remarkable trend. Each year, we introduce more chemicals into the equation, and yet every year there is an overall increase in pest and disease pressure. This is actually the definition of “unsustainable”. We can’t keep pouring on more and more, for less and less response."  Graeme Sait


 

Thanks, I’m learning more everyday.


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[Thian]

On 10/23/2018 at 9:26 AM, Klong Song said:

Would one of you please recommend a foliar feeding product. Thanks


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I use Resistim which is for foliar feeding against rootrot..it is a mix of potassiumphosphate and some other beneficials to keep the tree strong and healthy. I brought it from Europe though.

 

Also i prune the durian to keep it open so light and wind can go into the canopy easy.

 

When i see flowerbuds i spray seaweed extract (homepro) and that worked well last year. This big tree looks very healthy now.

 

My 2  small lab-lae duriantree's have yellow spots in the leaves and look crappy, they are in pots and i'll have to treat them better i guess (more sun).

 

I grew a big avocado on the same spot for years and it never had any issue except for the hass grafted on it, that always looked sick and finally died. (the tree consisted of 4 varieties). But i culled that tree since it never bloomed here in BKK.

Next to it i had a cocktail mangotree consisting of 25 different varieties grafted on it but that also had anthtracnose which i sprayed with sulfur/copper...that didn't work well though.

 

When you google for growing durian you'll see that the Thai use a different approach than the rest of the world...Thai don't use mulch and prefer chemical fertilizers against rootrot.

 

I prefer to grow my tree's without spraying chemicals, i only spray it in emergency but seaweedextract or multi-micro's i spray regularly...

 

About neem i noticed there are different strengths for sale...i now have a clear neem (others were brown) which costed much more and is much stronger...

 

0-52-34 fertilizer sold in thailand is mono potassiumphosphate against rootrot, that's sold in thailand in every plantshop.

 

I'm no expert at all and just use google for info. Durian is the most easy fruittree that i grow (i have loads). 

 

 

 

 

 

[Klong Song]

I use Resistim which is for foliar feeding against rootrot..it is a mix of potassiumphosphate and some other beneficials to keep the tree strong and healthy. I brought it from Europe though.
 
Also i prune the durian to keep it open so light and wind can go into the canopy easy.
 
When i see flowerbuds i spray seaweed extract (homepro) and that worked well last year. This big tree looks very healthy now.
 
My 2  small lab-lae duriantree's have yellow spots in the leaves and look crappy, they are in pots and i'll have to treat them better i guess (more sun).
 
I grew a big avocado on the same spot for years and it never had any issue except for the hass grafted on it, that always looked sick and finally died. (the tree consisted of 4 varieties). But i culled that tree since it never bloomed here in BKK.
Next to it i had a cocktail mangotree consisting of 25 different varieties grafted on it but that also had anthtracnose which i sprayed with sulfur/copper...that didn't work well though.
 
When you google for growing durian you'll see that the Thai use a different approach than the rest of the world...Thai don't use mulch and prefer chemical fertilizers against rootrot.
 
I prefer to grow my tree's without spraying chemicals, i only spray it in emergency but seaweedextract or multi-micro's i spray regularly...
 
About neem i noticed there are different strengths for sale...i now have a clear neem (others were brown) which costed much more and is much stronger...
 
0-52-34 fertilizer sold in thailand is mono potassiumphosphate against rootrot, that's sold in thailand in every plantshop.
 
I'm no expert at all and just use google for info. Durian is the most easy fruittree that i grow (i have loads). 
 
 
 
 
 

Thanks, I also want to try to keep the chemicals to a minimum. I will try to take the least toxic route and hope for the best.


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[Thian]

37 minutes ago, Klong Song said:

Thanks, I also want to try to keep the chemicals to a minimum. I will try to take the least toxic route and hope for the best.


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In that case i wouldn't worry too much for that anthracnose, unless all leaves of the tree look bad...the dry season is coming soon and that will change the climate for pests and diseases.

[drtreelove]

10 hours ago, Thian said:

In that case i wouldn't worry too much for that anthracnose, unless all leaves of the tree look bad...the dry season is coming soon and that will change the climate for pests and diseases.

That's an intelligent approach!  

[Thian]

2 minutes ago, drtreelove said:

That's an intelligent approach!  

Well durians are natives here, especially where i live. It's the most easy tree that i have, never has pests or insects.. Only thing they really hate is floodings, that killed a lot of them during the big flood.

 

When i read about Thai not using mulch or organic ferts i guess that works best in south thailand where the climate is more wet.

 

If you see how the durians from 600 us$ a piece are grown in nonthaburi they are planted on small dykes between watercanals...so it must be humid there as well all the time. The websites all warn for too humid conditions so i'm confused which websites to believe.

 

My durian also sheds leaves all the time, don't know if thats normal but it grows very well, too well cause i have to prune it regularly (don't want a giant tree) in my poststamp garden.

 

But it's best to plant several different varieties together so they can crosspollinate and will all give much more fruit.

 

I think the most important thing is to plant it on a small hill, never plant it in a valley where water likes to stand...They also like loamy soil. Mine grows in a raised bed from 40 cm high with lots of compost and close to other tree's.

Last year mine bloomed first time after 5 years and bloomed again 2 months later. I gave it a lot of potassiumsulfate plus droughtstress to make it bloom...when i saw tiny buds i sprayed seaweed-extract, got many flowers that i handpollinated and had 3 fruits....2 dropped and finally harvested the 1st durian which was perfect.

 

 

 

 

[JungleBiker]

On 10/23/2018 at 9:26 AM, Klong Song said:

Would one of you please recommend a foliar feeding product. Thanks
 

Polyfeed 20-20-20 + magnesium and micro nutrients. From Israel. Sold in Thai shops in green-plastic-foil packs of 1kg for about 120 baht or so.  I don't think it contains any calcium so you might want to also spray some calcium nitrate as a separate spray. 

[Thian]

8 minutes ago, JungleBiker said:

Polyfeed 20-20-20 + magnesium and micro nutrients. From Israel. Sold in Thai shops in green-plastic-foil packs of 1kg for about 120 baht or so.  I don't think it contains any calcium so you might want to also spray some calcium nitrate as a separate spray. 

That one from israel might be slow release fertilizer....that one costs 120....normal 20-20-20 or 16-16-16 is half the price...

 

I use japanese slow release fertilizer now which melts in 6 months time.

[JungleBiker]

On 10/29/2018 at 7:11 PM, Thian said:

That one from israel might be slow release fertilizer....that one costs 120....normal 20-20-20 or 16-16-16 is half the price...

 

I use japanese slow release fertilizer now which melts in 6 months time.

 

No, it's definitely not slow release.

You mix it with water and apply.

50 - 100 grams per 20 litres (typical volume of a knapsack sprayer).

Spray over the plant.

Made by Haifa of Israel but put into 1kg packs by a Thai company - with Thai and English script on the label. 

 

Yes, there are different formulations such as 6-12-40 + Mg and ME for fruit growth/quality. 

 

[Thian]

5 minutes ago, JungleBiker said:

 

No, it's definitely not slow release.

You mix it with water and apply.

50 - 100 grams per 20 litres (typical volume of a knapsack sprayer).

Spray over the plant.

Made by Haifa of Israel but put into 1kg packs by a Thai company - with Thai and English script on the label. 

 

Yes, there are different formulations such as 6-12-40 + Mg and ME for fruit growth/quality. 

 

I see, i used to buy the slow release from haifa...but it leaves empty pellets which don't totally melt.

 

I'm interested to know if the durian looks fine after spraying the 20-20-20 since i don't dare to do it. At this moment i don't give it anything except seaweed-extract by foliar sprays cause the dry period has started and i want it to bloom.

 

https://www.haifa-group.com/durian-trees-fertigation-foliar-feeding-recommendation

 

Here you see that the lowest dose for a durian (small tree like mine i guess) needs around 6 kg a year...i'll follow this scheme for my tree this year and start today.

 

but does anybody know what this means?: PF = Polyfeed drip of the different analyses indicated. 

 

I'll use 8-24-24 and hope it's right...

 

 

[Klong Song]

I see, i used to buy the slow release from haifa...but it leaves empty pellets which don't totally melt.
 
I'm interested to know if the durian looks fine after spraying the 20-20-20 since i don't dare to do it. At this moment i don't give it anything except seaweed-extract by foliar sprays cause the dry period has started and i want it to bloom.
 
https://www.haifa-group.com/durian-trees-fertigation-foliar-feeding-recommendation
 
Here you see that the lowest dose for a durian (small tree like mine i guess) needs around 6 kg a year...i'll follow this scheme for my tree this year and start today.
 
but does anybody know what this means?: PF = Polyfeed drip of the different analyses indicated. 
 
I'll use 8-24-24 and hope it's right...
 
 

Thanks guys, I am finding your information extremely useful.

[Klong Song]

 

No, it's definitely not slow release.

You mix it with water and apply.

50 - 100 grams per 20 litres (typical volume of a knapsack sprayer).

Spray over the plant.

Made by Haifa of Israel but put into 1kg packs by a Thai company - with Thai and English script on the label. 

 

Yes, there are different formulations such as 6-12-40 + Mg and ME for fruit growth/quality. 

 

Doing a quick search I can’t seem to find Polyfeed in the 20-20-20 formula. Would other formulas be acceptable?

[Thian]

32 minutes ago, Klong Song said:

Doing a quick search I can’t seem to find Polyfeed in the 20-20-20 formula. Would other formulas be acceptable?

No and i also wouldn't use the 20-20-20 this time of the year since it has too much Nitrogen which makes the tree's willing to grow instead of bloom....i don't know how old/tall your tree is though but if it's big/old enough to fruit you shouldn't give much N (from NPK).

 

Durian needs waterstress to bloom, cold temps also help. 20 days no water (some claim 10) will make the tree bloom and that's what you want of course (unless the tree is too small). Foliar sprays work much better than watering fertilizers in the soil....but be carefull cause it can also easy hurt the tree.

 

N is for growth

P is for blooming

K is for sweet fruit and a stronger tree.

 

Micro's are necessary if the soil is lacking them....they also help to let tiny flowerbuds grow better and open up. 

 

I don't know if my soil is lacking anything and micro's don't hurt if you don't apply too much of it...if you add too much the tree might even die and the soil can become unfertile so be carefull with them...seaweed is multi-micro but not very strong so you won't give too much easy compared to chemical micro-nutrients.

 

Too much water also isn't good for durian cause they can suffer from rootrot easy.

 

Depending of the size of your tree you can follow that scheme from Haifa..but for a young small tree it's best to use slow release fertilizers (for most sensitive fruittree's actually). They melt in 3 months or longer depending of the brandname.

 

If you want very fast growth you can give urea 46-0-0 and will see the tree flushing soon but that can also burn the roots if given too much...and if you give it the leaves will be full of nutrients that insects can smell and attract. Be carefull with it for durian but citrus like pomelo thrives on urea since they are high feeders and can stand it better. But also citrus will attract pests when they are high on Nitrogen.

 

So to make tree's bloom don't use Nitrogen at all or just a tiny bit....do that in combination with waterstress and low temperatures and they should bloom in theory.

 

Tree's that have an easy life (get watered every day) won't bloom...i have plenty of them haha but i grow many in large pots so it's easy to stop watering them. Of course the tree has to be old enough to fruit so if you have small duriantree's don't expect them to fruit and you can give the 20-20-20....But grafted duriantree's can fruit in 4-5 years in Thailand...seedlings take 8-10 years.