How long for Di-syston to leave a plant?

[chuckfranke]

Since my beloved roses are now organic and have been for about a year i am wondering - how long does it take before systemic pesticides are out of them?

The reason I ask - Rose hips... I tend to prefer not mixing nerve agents in my vitamin C intake whenever possible.

The soil around the roses is now INCREDIBLY active after compost, cornmeal and molasses - worms everywhere you look and they are fit little suckers.

Anyone know the persistence of Acephate or Di-Syston? used to alternate them for thrip control.

FWIW their thrip control properties kinda sorta suck... Inow have ladybugs and little spiders and no thrips.

[Nadine]

I don't know. Did you use per label, or did you have the same mentality I had years ago that using more would even do better? :oops:

If you are worried, use some nor-it on the site. This carbon activated charcoal product is not cheap, but just like many things, it is well worth the investment. Good to share with you again.
By the way, your posts are hilarious! You are fun!

[Enzyme11]

The short answer is that I know about the same about Di-Syston (disulfoton) as you probably already know. I haven't looked at acephate, but I'll edit and add it if/when I find anything. As to disulfoton, I haven't yet found plant persistence data specifically for roses. The synthetic world tends to consider roses to be merely ornamental, and persistence analysis for such plants tends to be in the areas of continuing pest mortality and of contact risk to people working among the plants. Your question is not concerned with whether the poison still is active enough to kill sucking insects. Disulfoton is a systemic organophosphate, but the clearance rate of it and its metabolites varies among host plant species. One report I saw showed that the clearance rate in tomato plants was ~ three times that in cotton. At least five of the intermediate breakdown products of disulfoton are toxic themselves; one of them formerly was a stand-alone pesticide, but it apparently has been removed from the market. I've seen data showing that one of the troublesome metabolites remained in a subject plant (not a rose) after about 9 1/2 months.

As to whether the residue concentrates in the hips (not to be confused with cheesecake) or petals, how much of existing residues one would consume by ingesting those in a typical quantity, and how dangerous that level of consumption would be, I don't know. Disulfoton breaks down faster in a rich organic environment, but I don't know whether high-organic soil greatly affects in vivo metabolism of either pesticide in the plant. (It's funny that pesticides in the soil break down best/fastest in 'organic" soil conditions, where they usually aren't used much, and worse in soil conditions where they are used.) One study indicated that boiling contaminated apple juice did not affect the disulfoton residue concentration. That would seem to imply that the process of making tea from contaminated rose hips would not ameliorate the residue. One would think that a year would be long enough, but it seems to me that pesticide metabolite persistence often is understated; without test data, it's hard to know. If I find relevant data, I'll post it here.