- Author: Tanya Kucak
A couple summers ago, some of my tomatoes produced little or nothing. At the end of the season, I discovered evidence of root-knot nematodes (RKN): galls on the roots that impair the plant's ability to take up water and nutrients. So last summer, I planted my vegetables mostly in the spots that did not have RKN, found several RKN-resistant tomato varieties, and planted my seedlings with lots of compost and some worm castings.
The result was an outstanding tomato crop. I found RKN evidence on some plants, but no plants failed. Of all the nematode-resistant hybrid tomato varieties I planted last year, four were standouts. All of these produced consistently throughout the season, until frost.
* Purple Boy F1 is a prolific dark medium-size tomato with a good flavor and excellent shelf life. I've grown it for three years and like it a lot. It's not as luscious as some of the big sandwich tomatoes I like, but its flavor is among the best of any hybrid I've tasted.
* Chocolate Sprinkles F1 is a delicious striped dark cherry tomato that produced well. It's a large cherry with a subtle point on the end. If I could only grow 5 varieties, this one and Purple Boy would make the cut.
* Bush Early Girl F1, a compact 2' bush, produced a steady crop of red round unblemished fruit. Itoutproduced the other 6 or 7 red round hybrids I grew. Red round tomatoes aren't my favorites, but everyone I shared them with loved these tomatoes! (This variety is rated as nematode-resistant, but the more common indeterminate Early Girl F1 is not.)
* Artemis F1, a small red cherry, was my partner's favorite. The plant was so huge and productive that I couldn't pick them all! This is a cherry best eaten in the garden or soon after picking, because it had a relatively short shelf life.
For additional nematode suppression this year, I seeded a cover crop of Kodiak mustard in January. This mustard will produce high levels of nematode-suppressing glucosinolates when it's chopped and incorporated into the soil. In a month or two, I will also grow a bed of French marigolds (including Nemagon), which also suppress RKN, and zinnias, one of the few plants not affected by RKN.
For more information on root-knot nematodes, see https://ipm.ucanr.edu/PMG/PESTNOTES/pn7489.html.
