Reduced hazard pest and disease control

[DavidCampen]

Since my new greenhouse is actually more properly a conservatory - attached to my home and also at times used by my wife and pets, I am interested in using less toxic pesticides and fungicides.

Before I converted this patio into an enclosed conservatory I have had problems with the usual pests - aphids, mealybugs, spider mites, whiteflies, fungus etc. I don't remember ever having a thrips problem but probably have had those too and just didn't notice

So, in anticipation of experiencing the same pest and disease problems in the (mostly) enclosed conservatory I have been expanding my pesticide and fungicide arsenal but trying to stay with the least toxic materials.

I used to use just garden store permethrin/PBO for insecticide and chlorothalonil for fungicide.

Inspired in part by the recent AOS magazine article about Azadiractin I have been researching additional less toxic pesticides. I have found a number of interesting materials that I plan to add to my arsenal.

First there is the Azadiractin that was discussed in the recent Orchids magazine article. I purchased a quart of the Azatrol brand for about $90 from an online hydroponics supply shop. Azadirachtin is a product isolated from Neem oil.

Next I found Spinosad which is a product produced by a soil bacteria. It is OMRI certified for use in organic food production. It can be purchased in garden stores under several brand names as a 0.5% spinosad content liquid for about $25 per quart. It is also avalable in quarts of 11% material under the name Conserve SC for about $150 per quart.

Third, I have purchased a 1/2 gallon jug of pyrethrin/PBO 5%/25%. Pyrethrin is the natural pyrethroid isolated from pyrethrum flowers. There seems to be a shortage of natural pyrethrum but I was able to purchase the 1/2 gallon jug for $105.

I plan to use the above three materials as a cocktail for insect control. I have already made one treatment with just Spinosad and have not seen any adverse affect on my plants.

[Discus]

I think Ray was recently raving about an orange oil extract for pest control; he's also recommending something called "sucrashield" at the moment.

Here's a long article on more "organic" pest controls from him : First Rays' Home Remedies.

[Ryan.Walsh]

I haven't used the Azadiractin but I have used Neem oil (DynaGro brand) for years. It works extremely well so I'm sure the Azadiractin will do just as well if not better. I'm not sure about the Azadiractin but the Neem oil is a fairly effective fungicide also.

The pyrethrin is also good but be careful with it on young tender shoots. I have seen burning on young shoots with pyrethrin applied at the recommended dose.

Good luck

[DavidCampen]

Yes, thanks, phytotoxicity is a concern that I am aware of and it is a significant reason that I am making a large effort to build up an arsenal of pest control agents now while I only have a couple dozen orchids in my collection and have time to experiment and watch for phytotoxicity. When I get to having a couple hunded plants in my collection and discover a pest problem I will want to be able to treat without waiting to test for phytotoxicity.

It is important to read the (multipage) label that accompanies each pest control agent. This label will mention what plants the agent has been tested on and if there are any plants for which the agent is contraindicated. Azadiractin does carry a warning that it can cause spotting of foliage in orchids, african violet and poinsettia.
Here is the label that accompanies the Azatrol brand azadirachtin:
http://www.pbigordon.com/pdfs/Azatrol-SL.pdf

Here is the label of a nice new systemic insecticide, brand name Kontos, but the label specifically states that it is not for use on orchids (and geraniums and ferns and several other plants).
http://www.ohp.com/Labels_MSDS/PDF/kontos_label.pdf

From reading a bunch of labels, it seems that african violet, begonia, geranium and boston fern are the plants that are most sensitive and I am guessing that if a pest control agent is listed as being acceptable for use on those plants then it will likely also be OK for orchids.

Even the specific formulation of a pesticide can affect its phytotoxicity. Oil based solvents, "stickers" and even nonionic surfactant "spreaders" can have phytotoxicity or increase the phytotoxicity of another agent.

Many pyrethrum formulations are in a solvent/oil base and I wonder if this might be the cause of some phytotoxicty. The pyrethrum/PBO formulation that I purchased is "Riptide" from MGK:
MGK - Riptide Waterbased Pyrethrin ULV
I specifically selected this because it is a water based formulation.

I sprayed spinosad (Monterey Garden) last weekend and have not seen any ill effects. This weekend I will spray with an azadiractin (Azatrol): pyrethrum/PBO (Riptide): spinosad (Monterey Garden) cocktail to test this mixture for phytotoxicity.

Originally Posted by Ryan.Walsh

I haven't used the Azadiractin but I have used Neem oil (DynaGro brand) for years. It works extremely well so I'm sure the Azadiractin will do just as well if not better. I'm not sure about the Azadiractin but the Neem oil is a fairly effective fungicide also.

The pyrethrin is also good but be careful with it on young tender shoots. I have seen burning on young shoots with pyrethrin applied at the recommended dose.

Good luck

[Ray]

David,

SucraShield is sucrose octanoate esters, and they create holes in-, and desiccate insect and mite adults, pupae, larvae and eggs, while most traditional insecticides are classical toxins. it is OMRI and WSDA listed for organic gardening/farming.

I am about to also carry a fungicide (waiting on a shipment) that destroys the living creatures and spores by relying on nanoparticles of soybean oil, and the the natural physical function of reducing surface energy to disrupt the cell wall.

[DavidCampen]

The sucrose octanoate sounds very interesting, I will have to put that on my list of things to acquire.
http://www.fcla.edu/FlaEnt/fe87p6.pdf

Originally Posted by Ray

David,

SucraShield is sucrose octanoate esters, and they create holes in-, and desiccate insect and mite adults, pupae, larvae and eggs, while most traditional insecticides are classical toxins. it is OMRI and WSDA listed for organic gardening/farming.

I am about to also carry a fungicide (waiting on a shipment) that destroys the living creatures and spores by relying on nanoparticles of soybean oil, and the the natural physical function of reducing surface energy to disrupt the cell wall.

[DavidCampen]

I sprayed yesterday. To make 6 liters of solution I mixed the following with RO water:

Monterey Garden - spinosad 0.5%, 200 ml
Azatrol - 1.2% azadirachtin, 60 ml
Bonide - 1% pyrethrin/10% PBO , 250 ml

This gives these concentrations in the final 6 liters of solution:

Spinosad: 0.017%
Azadirachtin: 0.012%
Pyrethrin: 0.042%
PBO: 0.42%

I treated all of the plants in my conservatory:
Cattleya, Paphiopedilum, Phalaenopsis, Encyclia, Dendrochilum, Zygopetalum, Dendrobium speciosum, Stanhopea; also Platycerium, african violets and Plumeria.

Now to watch for a week for any evidence of phytotoxicity.

The spray formulation was a bit stinky. I have rinsed and thrown away the Bonide Pyrethrin/PBO container so I can't check it but I suspect that this was the stinky ingredient. The Azatrol has only a slight smell and the Monterey Garden Spinosad also only a very slight and pleasant smell.

[3oranges]

I am interested in your results, particularly the use of Azadirachtin. Did it spot the foliage?

[DavidCampen]

Originally Posted by 3oranges

I am interested in your results, particularly the use of Azadirachtin. Did it spot the foliage?

A yes, I was wondering if anyone would ask. It is a bit embarrasing. I don't know if it was the Azatrol; I suspect the Bonide Pyrethrin/PBO, but I did do some damage to a couple of Cattleya leaves and killed a Dendrobium speciosum. A Stanhopea and Gongora did fine as well as some Dendrochilum and Laelias and a Brassavola.

I suspect either the piperonyl butoxide (PBO) synergist in the pyrethrin formulation or hydrocarbon solvent in the pyrethrin formulation. Next time I use pyrethrin, I will use the Riptide formulation that claims to not have hydrocarbon solvent, has a lower ratio of PBO to pyrethrin and I will also use a lower amount (1/2-1/3) of pyrethrin in the final mix.

The next time I use Azatrol I will use it alone and also in a lower concentration.

[littlefrog]

I've used azradactin on the entire greenhouse with absolutely no damage to flowers or leaves... Your mileage may vary. Plants in there include orchids of all types (of course), bromeliads, ferns, gesneriads, succulents, foliage... a little of everything.

I've also used spinosad with good results. When I tank mixed the azradactin, spinosad, and Distance (a systemic IGR), I did see some damage. Since neither of the first two did any harm, I suspect the Distance. Distance has been good to me, though. Only damage I saw was a few flowers.

I bought some sucrashield from Ray, but I confess I forgot I had it... Since I've seen a few mealy bugs and aphids around the last few weeks, I'll break that out next.

Rob