Our research on cover crops has focussed on the use of marigolds (Tagetes spp.) to control root-knot nematodes (Meloidogyne spp.). In greenhouse experiments marigold varieties were identified with high efficacy in nematode control. Subsequent field tests showed that selected marigold varieties, grown prior to a susceptible crop, lowered nematode populations and increased yields similar to soil fumIgation.

Relevant publications:

Ploeg, A.T. 2000. Effects of amending soil with Tagetes patula cv. Single Gold on Meloidogyne incognita infestation of tomato. Nematology 2:489-493.

Ploeg, A.T., and P.C. Maris. 1999. The effect of soil temperature on the life cycle and reproduction of Meloidogyne incognita on tomato and marigold. Nematology 1:389-393.

Ploeg, A.T. 1999. Greenhouse studies on the effect of marigolds (Tagetes spp.) on four Meloidogyne species. Journal of Nematology 31:62-69.

Marigold grown in field experiments for root-knot nematode control