Monday, July 9, 2007

Are Organic Pesticides Safe?

I don't have much time here, but I do have a question for the organic gardening veterans out there. In trying to Google organic solutions to my tomato plants' stink bug invasion(besides squashing 'em with my hands), I ran across some pesticides touted as organic, which I'm assuming means they're from natural sources.

However, when reading the fine print, I could not deduce whether or not they kill pollinators, such as honey bees, and I also saw a couple of notes stating that they could pollute water sources.

I also saw some discussion about "Bt," which I'm unfamiliar with. I AM familiar with genetically modified this the same thing, and therefore to be avoided like the plague?

Pardon my ignorance. The question here is to reap the cumulative wisdom from so many of you whom I appreciate, who are far far ahead of me in practical knowledge of these things from experience.

My hesitation to just go out and buy something labeled "organic" stems from two things:

1. I'm cheap. The purpose in doing the organic tomatoes was in part to raise good food economically, without each fruit becoming the proverbial "$60 tomato."
2. I'm cynical, or well let's just say cautious, about claims made by companies promoting pesticides. Even the "safe for animals and humans" sort I saw on my cursory Googling attempt had ingredients which on other sites were tagged with cautions about exposure.

Is there a time and a way to use such, or are trap crops and diversity plantings for the encouragement of beneficial insects, etc, the best way to go?

I did note on one site specific to stink bugs that they were not usually a widespread problem BEFORE the advent of genetically altered (perhaps this is the Bt that was mentioned??) crops, specifically cotton engineered to be more boll-weevil resistant in the Deep South. According to that article, the reduction of that particular "pest" led to a different balance and opened the door in different ways to the rise of stink bug infestations for a whole spectrum of soft fruits and soy beans, now difficult to counteract.

Any thoughts from the blogosphere on these things? Thanks to Phelan for her comments about this recent development. My garden's infestation is now beyond the squashability threshold...


Thanks in advance for advice!


e4 said...

I'm not an expert here, but I'll tell you what I do know... I've had good luck with Neem-based products. And Bt is short for Bacillus thuringiensis which is just a type of soil-based bacteria that goes after certain larvae, like caterpillars, grubs, etc. I might be wrong, but I don't think it works on adult bugs.

My copy of The Organic Gardener's Handbook of Natural Insect and Disease Control says this about stink bugs:

"Control weeds in susceptible crops; remove or mow weedy areas adjacent to garden beds; attract native parasitic wasps and flies by planting small-flowered plants. As a last resort, dust with pyrethrin."

(Pyrethrin is typically made from chrysanthemums. Don't know if there's a homebrew version...)

april said...

Hi Robbyn,
Warped people gain high marks on my are now one of them.

No gong for you.

Patrick said...

I came here via Mike's post on Planbe.

I agree with everything Mike says, and I also agree with what you say about your reasons for being reluctant to go out and buy organic solutions when there is a better way.

I never use any pesticides, organic or otherwise. I also almost never use any fertilizers. One of the most important reasons is because these products rarely have a useful purpose, and there is almost always a better way.

For fertilizer, if you use compost you don't need any. The only reason to use fertilizer is if for some reason you can't use compost, and even then it's not always necessary.

Using pesticides, like Mike explains, will almost always make the problem worse in the long run. In addition, there are some untreatable problems (like tomato and potato blight), for which nothing works. Trying to use organic or non-organic pesticides, will just be a waste of money and will lead you into a cycle of buying ever more expensive and toxic products, expecting that something will eventually work.

The most important things you can do to prevent insect and disease problems are to use compost, practice good hygiene including removing infected plant materials as they appear and removing insect pests by hand if possible.

Now, having said all of this, the one exception might be Bt. This won't work on stink bugs, only certain types of caterpillars and other larvae. I personally don't use it, but I might in the future. If you grow cabbage and related plants, it can be a lot of help. It is just a naturally occurring bacteria, and it's not very toxic. It is the same thing as what they use with GM crops, but what you use in the garden is on a much smaller scale and much lower concentrations. I have several friends that use Bt, and are very happy with it.

I would never use Pyrethrin. Some people make pesticides by liquefying tobacco plants in a blender. Tobacco is just as toxic for the environment in this way as it is to people. It's easy to make something very toxic from natural ingredients if you put your mind to it.

farmer, vet and feeder of all animals said...

Hi Robbyn:
I am sorry I have seemed "lost". Thanks for all the comments though.
Neem---we use it too. Very stinky smelly stuff so don't get it on your hands---the smell lingers. Invest in the tried and true "oil" that you can buy on line in a brown glass bottle---don't go to home depot and get the neem there (though the brand SAFER does work but I prefer the "mix it myself" stuff). The cost in the long run is much better and the concentration factor is too.
Also try a soapy water solution---gives the bugs a belly ache. About a tablespoon of soap (dove, ivory or better yet any all natural soap you might have like Basic H or something) with a tablespoon of neem (tobacco juice also works---get a bag of "chaw" and soak it in water) mix in a gallon of water and apply. Early morning or late afternoon are best. I personally like late afternoon unless your having a bad mold experience---it sits overnight and gets them late and early the next morning.
Also---good ole hand picking and dropping or pushing/shaking them into soapy water. Though stink bugs/squash bugs etc are quick as lightening---that trick works much better early in the morning with japanese beetles and june bugs.
Hope that helps
Good luck!

Laurie said...

You should always read up on any type of poison, organic or otherwise. Remember that poison ivy and rattlesnake venom are all 100% organic so "organic" by itself doesn't mean "safe."

I've never used anything but Safer soap, and picking bugs off with my fingers, but I've never had your particular problem.

Don't rely on the garlic/cayenne pepper remedy. I grew cayennes one year for the sole purpose of making this spray. Bugs ate my cayenne peppers!

Jane said...

Bt, bacillus thuriengensis, is the same as in BT genetically modified crops. The difference is organic farmers are permitted to spray Bt on their crops; genetically modified Bt crops have the Bt built in. Spraying on organic crops can inadvertently kill insects in the same insect family as the target family (spraying for cabbage moth can kill other moths and butterflies that aren't endangering your crop but just happen to be in the field). Bt built into the crop, as in genetically modified Bt crops, only kills the target insect that eats that crop. Much more sustainable, and without killing non-target insects.