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Windsor, Ontario, Canada

I sprayed bifenthrin 4 days ago. Will be there be any issues with spraying a systemic fungicide now? Will the bifen residual stop the systemic from being absorbed? Will the spray wash the bifen away? Will there be any bad interactions? Tremor?

Thanks

6/16/2007 12:21:27 AM

Ctpumpkin@optonline.net

You're OK to spray in the cool of late afternoon.

Good question about penetration. Systemic fungicides are really just acropetal penetrants. They don't enter the vascular system of a plant & move around. Rather they enter between guard cells. Bifenthrin cannot alter the guard cell arrangement. I suspect that if anything did, the plants would suffer mightily.

It has been thought that some anti-transpirants would interfere with plant absorption but the research hasn't been widely published that I am aware.

6/16/2007 10:19:57 AM

Windsor, Ontario, Canada

So if I am spraying systemics in general, how much should I care about complete coverage? If they dont move around the vascular system, do you still have to get full coverage? Is spraying the tops enough if it absorbed?

Further, as long as a pesticide (let me use what I spray for the example) bifenthrin, and a fungicide (both myclobutanil (immunox) as a systemic and chlorothalonil (daconil) as a contact) mix properly and dont separate, is it ok to combine them? What possible chemical interactions could be expected?

I always spray in the evening, and sometimes near dark to avoid any burning problems. I dont spray tips either. I figure, less spraying is easier/better, and if you are going to spray at/in the dark, a fungicide would eliminate any issues with drying leaves in the dark.

Thanks again. Oh, just out of curiosity, what is your background in the ag industry.

6/16/2007 10:49:41 AM

Ctpumpkin@optonline.net

Certified Pesticide applicator in several capacities since 1983. Have also worked for a manufacturer & a formulator but now back with another distributor.

You still need to spray both sides of the leaves. There are some strobilurin fungicides that have translaminar properties (Compass/Flint for instance). Meaning the fungicide will gas-off & recollect elsewhere but this is not a good excuse to misapply the material.

Heritage/Quadris seems a little better than most at moving all the way through a leaf but this isn't true about many other fungicides.

6/16/2007 4:28:13 PM

Windsor, Ontario, Canada

Nice, to have someone so knowledgeable in the forums. I/We appreciate all the help. Do you think mixing either myclobutanil/bifenthrin or chlorothalonil/bifenthrin would be a problem, or should chemicals always be applied seperately?

6/16/2007 5:26:41 PM

Ctpumpkin@optonline.net

I've mixed 2 elements together many times but I try to watch the weather & temperature a little more closely. Eagle plus Talstar is a common tank mix here & we've never had trouble with it.

I would be more cautious with chlorothalonil. It is the only fungicide I've seen cause plant injury here even used alone though many others say they've not experienced problems with Daconil.

BUT

I always use the LOWEST rates when spraying young pumpkins. Even half rate applications. The young growing tips are already very sensitive. So if we make half rate treatments every week we eventually end up with the correct dose with MUCH less chance of plant damage.

6/16/2007 10:37:35 PM