growmoxone

Kay,
Gramoxone is a contact acting weedkiller which will kill any soft plant material that it comes into contact with. If your potatoes are above ground level now, then spraying with Gramoxone will kill anything that's visible and accessible to the spray. This will be very damaging and make it difficult for the crop to recover. It had a label recommendation for pre-emergence use in potatoes but not for more than 10% crop emergence. I would expect your crop is way too advanced to spray safely.

To answer your two questions

(1) If you do decide to spray, then the spuds will be safe (assuming you'll actually get a crop worth harvesting) Gramoxone isn't transported in the plant unlike Roundup so it won't reach the tubers.

(2) Gramoxone is deactivated when it touches the soil, so sowing a following crop in the same area is safe. The only concern is spray drift. If spraying on a windy day, some spray might drift onto another crop, this will certainly cause damage,light to severe scorching but it depends on how much drifting actually occurs.

Overall, I think spraying now will cause serious damage to your crop. Spraying the field before planting your potatoes would have been much better.

Hope this helps,

Yes is the answer to both questions. It will kill all green life above the ground but jondaine is correct it will not be transferred down to the tubers but if they are in infancy I would expect there to be none anyway so you may render your potato crop useless.

The important question is, what type of weeds do you have. If you have problems with nettles and couch etc, or other deep rooted weeds, gramoxone is not the answer.

If your potatoes are just starting to come up you will be all right . Gromoxone is used by farmers for this very job.The potatoes will be safe to eat . Any chance of a pic to see what size your potato plants are?

In the old days people planted potatoes to clean the ground up wich usually invovled lots of hoeing but lots of people forget about the hoeing part of the operation so if you can get a small army together to do the hoeing you will have to spray jacob

growmoxone

Many thanks for all the replies. The spuds were about 3inches tall, but now with all the rain are about 6/7 inches. Pink Fir look ready to flower soon. We have decided to fit a hood to the sprayer and spray between the rows only, let spuds grow, harvest, then spay again before planting fruit in the autumn.
Reassured about eating.

Thanks again!

Kay

Watch out for spray drift!
I know you intend using a hood, but potatoes and tomato's are particularily susceptable to weedkiller.

It only takes a few microns!