Following is an edited summary of the 9 responses I have received to date on organic control of field bindweed (Convolvulus arvensis), also known as creeping jenny or small morningglory. Authors/addresses were deleted. They are in no particiular order. I hope I have not left anyone out. Thanks to one and all for taking time to respond.

1. I am not sure how large the acreage is but sometimes using an organic mulch like straw can help to smother weeds, but organic mulches must be spread onto a clean surface and must be thick enough to cover the entire soil surface to shade our weed seedlings. There has been research that shows a reduction in broadleaf weed seedlings when rye is used as a cover crop. Rye has allelopathic effects on broadleaf weed germination.

2. I can tell you it is a serious problem here too, even on ground fumigated with methyl bromide/chloropicrin. It would seem any "top kill" would result in carbohydrate starvation (e.g. flaming/sharpshooter) and would eventually be effective. But how many years would it take?? Seems Dr. Clyde Elmore at UC Davis did some work in the past on this or other perennial weeds to determine how quickley one needed to come back to kill new growth so that there is a net reduction in food reserves - I think it was fairly quick as I recall..........very important for the CHO starvation to be effective.

3. We have a few patches of bindweed on our 3 acres of organic vegetables, both field and hedge. We have tried covering it over with black plastic for the whole season; when we remove the plastic in the fall it comes right back. We have tried full-season bare fallow as well as "smother" crops like buckwheat with the same results. The stuff drives us nuts. Apparently, the root systems can go down 30 feet or more, so it is quite difficult to exhaust it. You can hoe it one day and it will grow back by the next.

4. Bindweed is, *I think*, very similar to wild buckwheat which grows here. If it is, it is very susceptible to flaming, at least when young. Because it keels over more easily than many crops, it *might* be possible to flame certain emerged crops fairly aggressively to get the bindweed. Certainly flaming controls wild buckwheat very well (crop) preemergent. Caution advised, tho. ;-) I use geese as weeders, but I'm unsure whether they eat buckwheat or bindweed or not. If they do, certain crops such as potatoes, strawberries etc. could be cleaned up that way. It would require segregating goose tolerant crops from crops considered palatable by the geese. I find that mulching is not very effective in controlling buckwheat.

5. In my experience, bindweed thrives on fertility. As you improve the soil the bindweed gets more invasive. This is why rotation is important. I have observed strong alleopathic effects when spring barley is planted in soil infested with bindweed. I seem to remember that it burned down the bindweed like an herbicide. You could try a few strips of barley in your garden. This effect takes place early in the growth stage of the barley. mybe you could incorporate it as a green manure, and plant something else after.

6. I would want to look at the soil test with the suspicion that K might be high in relationship with Ca. One would want first to make sure Ca is arount 70% of the cation exchange capacity in terms of base saturation %. They I would recommend green fallowing after deep plowing. I suggest deep plowing because bindweed has deep rhizomes and sends up shoots which will be severed by the horizontal slicing action of the plow. Green fallowing may seem expensive compared to herbicides but at least is has the additional value of improving the soil's overall fertility and quality while combatint weeds. I suggest planting an vigorous green manure crop with inexpensive seed cereal grains, buckwheat, etc or mixed with legume such as vetch. When 16" to knee high disc or rototill into the top 6" of soil along with any weeds which will be struggling along in this enormously competitive environment. At disc down this is a good time to add compost or manure and other fertilizers especially rock phosphate (the biological activity associated with green manure incorporation generates lots of organic acids which help weather rock fertilizers. As soon as initial decomposition is well underway, one should replant another green manure crop. A typical sequence I have used several times to eliminate perennial weeds goes like this: Late summer or early fall - rye and vetch. Late winter - manure on green manure crop as new growth begins Late spring - disc down and replant to buckwheat or oats with peas. Summer - disc and replant buchwheat. Late summer plant vetch with rye again to provide overwinter cover - this field will be very well suited to organic vegetable production the following spring. This will reduce annual weeds very effectively as well and will probably eliminate soil borne crop diseases for the several seasons to follow. One alternative might be to turn active swine into the field in hopes they will rid the soil of bindweed but I think the green fallow is far more effective and beneficial for future production. I hope this proves usefull to you, and would be interested in hearing how things turn out......

7. I have been working on trying to control field bindweed with vinegar. I have used two volumes, 20 gal/a and 40 gal/a of straight vinegar (5% acetic acid). The best control with 20 gal/a was about 15% - not too good. When I doubled the volume, control was as high as 60% and averaged 50%. I plan to continue this work, looking at sequential applications - perhaps two or three applications at tow to three week intervals or to use a higher concentration of acetic acid (10% or higher). Up to this point, I have been using regular vinegar from the grocery store, but to increase the concentration and lower the cost, I will start using glacial acetic acid, available at any chemical supply company. Glacial acetic acid is what food companies buy and then dilute with water to make vinegar. The price I heard was $6./gallon, which will make 15 or so gallons of vinegar.

   Sharpshooter or Scythe - These are two different names for the same active ingredient - pelargonic acid. Scythe, the current name, is made by Mycogen corporation. It is a contact herbicide, very effective against annual weeds. I know that Mycogen is trying to get this materail approved for use by CCOF, but I'm not sure where it currently stands. In my comparisons of Scythe vs. vinegar, I didn't see a lot of differences, although I did not look at Scythe for field bindweed control.

8. I am not sure how large the acreage is but sometimes using an organic mulch like straw can help to smother weeds, but organic mulches must be spread onto a clean surface and must be thick enough to cover the entire soil surface to shade our weed seedlings. There has been research that shows a reduction in broadleaf weed seedlings when rye is used as a cover crop. Rye has allelopathic effects on broadleaf weed germination.

9. If the bindweed isn't wreaking havoc on production, I'd leave it. We found bindweed drew some of our destructive insects away from our crops.