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Biological Controls #8? Control Powdery Mildew

Microbeman

Microbeman

The Logical Gardener
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Actinovate;

Originally Posted by Microbeman
Actinovate is Streptomyces lydicus (bacteria). I'd be very interested to know if it is effect against PM

Well you're in luck. I just found some PM near my cool air intake and I have some Actinovate. Trial test this week,I'll let you know what becomes of it. I'm assuming it will be one of those things where continued applications are needed every few days..who knows.
 
Microbeman

Microbeman

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I hope I did not jump the gun starting up this thread. If Cheese and George have not already placed their posts elsewhere, please put them here.

Controlling Powdery Mildew (PM) is a giant deal. There are many strains/species of the family Erysiphaceae and some ones introduced to North America in the past 15-20 years. To fight something, I believe it is best to understand it and unfortunately PM is relatively complex, changes stages and is apparently hybridizing.

From a bit of research today it 'appears' the species 'mostly' effecting cannabis/hemp are;
Podosphaera macularis [aphanis]
(formerly Sphaerotheca macularis) First seen in the west in 1996 in Yakima valley where it destroyed crops of hops and has since spread throughout the west and has opened up its appetite to include some other crop species and some species of weeds. In its aphanis variation it effects strawberries.
AND
Leveillula taurica (anamorph; Oidiopsis taurica)
introduced to Florida 1971; effecting chili and bell peppers, tomatoes, cotton, globe artichoke, onion. Leeks, tomatoes and can also infect weed species.

Although Actinovate (Streptomyces lydicus) claims that it can control PM, I could find no direct evidence by way of trials to support the claim yet. [a certain member who used to get peer reviewed papers for me is no longer with us:tiphat:] I've attached a paper which outlines some fungal pathogens it was effective against. I also attached a document from UC Davis about PM. It appears that Actinovate is effective against some fungal pathogens and it has been determined (hoped for) that it may be a broader fungal pathogen antagonist. If it works, it works. Be mindful that just spraying water on PM controls it (or some species) to a large degree.
http://pmep.cce.cornell.edu/profiles/biopest-biocont/biofung/strepto_lydic/actinov_reg_0305.html

My opinion is that PM is encouraged by higher amounts of nutrients but that is only a speculative hypothesis at this point. To beat back an outbreak of PM, I think what is needed is an organism which devours it. I am (slowly) working on two angles to this, one bacterial, one fungal.

Our PM problems in our greenhouse a number of years back subsided when we stopped using fertilizers and used compost tea consistently. Because we had no control for comparison, it cannot be determined that this was causational.
 

Attachments

  • Streptomyces lydicus WYEC108 as a Potential.pdf
    962 KB · Views: 29
  • ucDavis.pdf
    336.1 KB · Views: 46
N

Nondual

Serenade - Bacillus subtilus

AQ-10 - pretty sure the original company distributing it went down but another bought the rights and available somewhere.

Ampelomyces quisqualis isolate M-10 is a naturally occurring hyperparasite of powdery mildews. This parasitism reduces growth and may eventually kill the mildew colony. The mycoparasite is not restricted to powdery mildews. In vitro work indicates that it can be parasitic on Botrytis cinerea Pers. Ex. Fr., Alternaria solani (Ell. & Mart.) Sor., Colletotrichum coccodes (Wallr.) Hughes, and Cladosporium cucumerinum Ell. & Arth (Jarvis & Slingsby, 1977) There is no information indicating that A quisqualis shows infectivity or pathogenicity to any organisms beyond this relatively narrow taxonomic range of fungal pathogens. Indeed, its life history strategy as a hyperparasite, would tend to preclude a wide host range.

It infects and forms pycnidia (fruiting bodies) within powdery mildew hyphae, conidiophores (specialised spore-producing hyphae) and cleistothecia (closed fruiting bodies of powdery mildews). Having penetrated into the mildew hyphae, the fungus produces pycnidia, in which form the pathogen can survive adverse periods e.g. winter, in and around the host plants of the mildew fungi. The pycnidia produce spores, which require favourable conditions for successful germination e.g. in terms of temperature, moisture and in particular the presence of the appropriate host. Over-wintering pycnidia can also be produced saprophytically in vascular plants e.g. in mildewed clover leaves and in cucumber leaves (Yarwood, 1939). The infectivity of the spores produced by the pycnidia rapidly diminishes under field conditions (e.g. 24 to 48 hours), although this can be extended under appropriate conditions.

Sundheim and Krekling (1982) demonstrated that A. quisqualis produced specialised appressorium-like penetration structures on powdery mildew. Penetration of the host cell was probably due to mechanical and enzymatic processes. Furthermore, enzymatic digestion played a major role in the invasion of the host cell and the destruction of cytoplasm. Invading hyphae penetrated the host cells through the septal pores of the host. Beuther et al (1981) studied the effects of extracts from the hyperparasite on growth, sporulation and conidial germination of the host. They found no evidence of toxin production.
Click to expand...
Calcium deactivates the pectolytic enzymes produced by powdery or downey mildew condida and stops the PM from 'rooting' even deeper/more into plant tissue. The condida spread in between plant cells where pectin predominates, and I could be a bit off there, can be inhibited with increased calcium levels. Visible PM is the mushroom (fruiting body) of the hyphae (mycelium). While that may not be the correct scientific way of describing things I think people get the picture.

I'm a bit rusty on the hyphae/condida thing.

Foliar calcium for PM helps! As a plant matures in the flowering cycle it's under stress and basically dying so PM becomes more prevelant the deeper you get to flower...IMO. Serenade always seemed to work great early on but the more you used it, and also the more mature the plants were (deeper in flower), the less effective it seemed.

My opinion is that PM is encouraged by higher amounts of nutrients but that is only a speculative hypothesis at this point. To beat back an outbreak of PM, I think what is needed is an organism which devours it. I am (slowly) working on two angles to this, one bacterial, one fungal.
Click to expand...
I have heard that when N is used to excess it can promote PM issues. Instead of the 'higher amounts of nutrients' thing the flip side of sorts is having unhealthy plants which are disease and pest magnets. A treatment can also be looked at as a bandaid.
 
N

Nondual

Microbeman said:
link for the quote? Sp; condida = condidia
Click to expand...
I'm not so technical like you about these things regarding proper scientific lingo. I looked and actually it's conidia. I remembered it as condida that were the roots penetrating but guess that's the hyphae. I think you have it from here cause I seem to be pretty wrong.
 
Microbeman

Microbeman

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Nondual said:
I'm not so technical like you about these things regarding proper scientific lingo. I looked and actually it's conidia. I remembered it as condida that were the roots penetrating but guess that's the hyphae. I think you have it from here cause I seem to be pretty wrong.
Click to expand...

yes I mispelt it too; haha
 
Microbeman

Microbeman

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Do you have a link for your quote? BTW, I'm not arguing with you in the slightest. Don't stop posting.
 
Microbeman

Microbeman

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Nondual said:
What were the fertilizers?
Click to expand...

Our PM problems in our greenhouse a number of years back subsided when we stopped using fertilizers and used compost tea consistently
Click to expand...

Prefer the whole quote. Any and all fertilizers; zero zilch nadda

We had experimented with many types of fertilizers, typical & organic (OMRI certified)
 
guest2012y

guest2012y

Living with the soil
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Actinovate.....well it works,yet as I suspected and as the directions indicate...an application every 7 days to protect new tissue.

I sprayed the flowers to see if it burns the hairs...it did not burn the hairs on any of the plants in the spray area.

I would and do spray bacterial concoctions around 15 mins b4 lights out...that way the heat,light,etc. doesn't discourage the bacterial colonies from forming...right?

I have not reached full PM attack mode yet...I suspect as the season progresses and the flower size increases I will have more opportunity to play with Actinovate in the next few weeks.
 
jaykush

jaykush

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id also like to add to this thread that there are certain species of ladybug that eat PM right off of leaves. they are not your average red and black spotted ladybug. one species is yellow and has many small black spots.

i have seen a few, but have not gone out to observe them eating the PM on some of the wild plants around here.
 
guest2012y

guest2012y

Living with the soil
Veteran
I've tried everything with PM and have a rather close relationship with this thing. The observations I make and the solutions I use work simply due to living with it. I've a list of 'do's and dont's' that keep me in the game without ever losing my crop to PM.

The big winner for me is bacterial controls..they work if you are attentative to your garden,yet the environment is everything. The organic bacterials such as Actinovate only protect the treated tissue and have to be re-applied. Some colonies of PM eating bacteria may die off in a couple days and leave the leaf tissue unprotected.

The conditions in which PM needs to grow need to be avoided...control that and you control PM. After you get it in your room it's all about treatment and future prevention.

A week later after the Actinovate application there is no sign of it returning....so far.
 
guest2012y

guest2012y

Living with the soil
Veteran
Double post.......but,I should also say that for 20 dollars you get a pouch of Actinovate that has 2 oz's of a white powder in it. 1/2 teaspoon per gallon of water for a foliar spray. Not bad considering that that 2 Oz's will last a long time at that rate of application.
 
Last edited:
jaykush

jaykush

dirty black hands
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Our PM problems in our greenhouse a number of years back subsided when we stopped using fertilizers and used compost tea consistently
Click to expand...

i didn't see this but i agree, i have noticed that not only with PM and pests but larger organisms like deer for example will go for a "fertilized" plant long before they will an identical plant that has been naturally grown( mulching, polycropping, etc...) i really dont understand the whole concept fully but its almost like we are unintentionally "Sweetening" up our plants for pests, for no reason at all. not sure what to call this but i think its a valuable topic to discuss for moving natural farming forward.
 
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