Marigolds aren't a 100% fix but their performance was pretty impressive in a study that is currently being conducted by Antoon Ploeg; a nematologist and UC Riverside. I was at a UC research field day about a month ago and he was showing off his latest study. Planting French marigolds before tomatoes was giving control similar to commercial nematicides. When the marigold roots are penetrated, their response is to produce chemicals that kill nematodes. The one that's most likely to have this effect is called "α-therthienyl". Here is a link to a study that goes into the process in painful detail. You have to plant them though. Marigold tea and other stuff won't work because the roots have to be present and then be attacked for the chemical to be produced. For tons more nematode information from a local extension guy, check out his site and links His study also included some of the resistant varieties that Jean was talking about and they were performing much better than other varieties. When the resistant varieties were planted after marigolds, the plant vigor and production was very near that of the control group. Then too, always mix at least 2 inches of compost into the bed before you plant. is also good advice since it helps increase the population of beneficial bacteria, fungi and predator nematodes that aid in control.

Jo, I don't think they could have traveled from your soil to the styrofoam cups unless you flooded a bed with irrigation water AND the water ran over to the cookie sheet AND the water found its way up into the cups AND so on and so forth. So, please stop blaming yourself and relax, OK? I agree with PHJ and Dodie that it is likely she already had nematodes in her soil too. Root knot nematodes are incredibly common in southern parts of the country that have soil with a high sand content. In parts of Florida the RKN's are so bad that you have to raise tomatoes in containers elevated well above the ground so that the RKNs cannot travel via rainwater up throught the pots' drainage holes. Most photos I've seen from Florida posted by people who are fighting nematodes show their pots raised at least a foot above the ground and sitting on stone or cinder block walls, decks, etc. Y'all know, too, that the nematode-resistant varieties of toms can sometimes outlast the RKNs, right? So that explains why you'll often see them hit some plants but not all plants. Some plants resist or tolerate them well and others don't. Dodie, you're a real sweetheart and Jo's so lucky to have you for a friend! Dawn

RKN would be rare if you haven't had problems with them before and if you do have them then they are already throughout your soil so problems should be seen in other plants as well. Sacrificing one plant won't prevent further contamination but it is the only way you can confirm them. So if you wish you can pull up one plant and check for the root galls. But there are many possible reasons for wilts with tomatoes and stem knots on tomato stems are often nothing more than normal primordia. But to be sure we'd need some additional info or a photo if at all possible. Dave

Does anyone know if beneficial nematodes will destroy tomato root knot nematodes? And why would my Champion VFNT tomatoes get root knot nematodes? Doesn't that "N" stand for nematode resistance? Thanks **** No, beneficial nematides don't destroy RKN's The reason your Champion VFNT came down with RKN's is b'c the diseases listed after the variety name indicate not resistance, as in 100% resistance, as in the plants will NOT come down with a specific disease, rather, they indicate a tolerance to a disease. The tomato industry changed the word resistance to tolerance quite a few years ago after several large commercial tomato growers sued the seed sources b'c their plants came down with diseases they were indicated as being resistant to. I use the word tolerance when talking about disease, but most seed sources, hybridizers, etc, continue to use the word resistance. The disease tolerances listed after a variety name, then, many times allows for an extra couple of weeks growth and for commercial growers that's often time enough to get the sugar readings up ( Brix) which allows for a harvest, but sometimes not. In a given location both disease pressures and environmental conditions can dictate what the outcome will be. IN places where the RKN's have built up to destructive populations the soil usually is sand based and the RKN's move easily from sand grain to sand grain via the water shell around each grain thus spreading easily. Carolyn