July 14, 2016

Good morning, Root knot nematodes can very easily cause a gardens demise. Once you get them, you will always have them, with luck in a somewhat controlled state.

I have tried a number of “controls” with different degrees of success.

This year , I have mentioned on several occasions that I am using Azagaurd and administer it through my drip system. I have pulled some plants to examine the roots. I have not noticed the huge galls that I have gotten in the past. Also there are only 3 beds where I have noticed plant mortality. One plant did not show galling and is a point of confusion for me as to what caused its demise. As for the other beds RKN was the cause.

I have noticed in some of the beds that I know are infected with RKN wilt on these hot sunny days . But with the drip system they can be rehydrated. These areas do produce veggies but at a much reduced rate. It will be interesting to inspect these roots come this fall.

It has been documented that cereal rye (not annual rye) is a trap crop. What information I have gleamed is, the females enter the roots and the young can not leave. I would be glad to hear from anyone that may have heard different. Cereal rye is most often used as a winter cover crop and seems to be planted at that time for a trap crop too.

Now there are a lot of tasks that I do in the garden that do not fully occupy my mind, so I find myself getting into some serious dissecting of subjects and this cereal rye trap crop is one of them.

This winter planting of cereal rye to trap nematodes does not seem logical and the best you would do is build biomass in the garden. Building organic matter in the soil is also one of the control methods for RKN. The decomposing organic matter reeks havoc on RKN ( actually it is the bacteria decomposing the rye) but would not trap them.

So back to the cereal rye trap crop. During the winter RKN either go dormant, die or for any rate do not pose a problem to plants. RKN are active in soils above 60 degrees. RKN do not move deeper into the soil horizon because they are very slow movers. It is mechanical means that they do most of their traveling and not on their own. Studies have shown they move less than a foot per year on their own.

I have nothing to back this up with but I suspect that the adult RKN die when the soil gets cool. It is the eggs that hatch in the spring that infect the bed (eggs are a very secure and safe for pests, it is when they are least vulnerable). This is why when removing infected plants, removing as many of the galls is a very good thing.

So as all this is bouncing around in my brain, I think why not plant the cereal rye during their active time of year and then bake the rye with clear greenhouse film. If my premise that the females enter the plants, lay eggs and the young cannot leave this would have a potential to reduce their populations.

Of course this sounds good on paper. I have a squash bed that is in maturity decline (of course hastened by the RKN) and a portion of a cucumber bed that has a replacement already in place. Soooo we will give this a whirl. There will not be anyway to quantify this until next year. Of course as if I need any inspiration to look forward to the next season. Anyone with RKN experience with cereal rye trap crops, I would most certainly like to hear from you. Thanks in advance!!

There are a number of resistant crops and most are in the mustard family. These crops I grow in the cooler months when RKN is not active. Most of these mustard crops do not grow as well in our summer heat. I have grown Idaho Gold Mustard that has been reported to have nemacidal properties. Here again, I have grown this in the winter and have turned it in well before the RKN are active. So it is hard for me to quantify the effectiveness of these crops resistance or nemacidal properties they may have. Here again I do have some Idaho Gold Mustard that I need to see if it will grow in our summer heat.

This week I will harvest chard, kale, lettuce, carrots, green beans, summer squash, butternut squash, cucumbers and tomatoes. Please ask about quantities.

Iam experiencing some problems in my chili and eggplant beds. I have no idea if there are any to harvest. Likewise with my tomatoes, although I have noticed the toms have started to regrow. I should not run out of them but there will be a diminished supply for a while. It has been a strange growing year with some anomalies that have been confusing. I am hoping to rectify this in the near future.