Evaluation of diverse cover crops as hosts of two populations of soybean cyst nematode, Heterodera glycines

Abstract

Soybean cyst nematode (SCN; Heterodera glycines) reproduces on a wide range of plants, including some cover crops. However, reproduction of SCN populations on a number of cover crops has not been investigated in the northern Great Plains. Thirty-five cover crop species/cultivars from four plant families were evaluated as hosts for SCN. Greenhouse evaluations were done with two common SCN populations, SCN103 (HG type 0) and SCN2W (HG type 7) under controlled conditions. The sources of two SCN populations were two soybean fields of North Dakota. After 35 days of growth, white SCN females were extracted from individual plants and counted to determine a female index (FI = average number of females on a tested crop/average number of females in a susceptible check x 100) for each crop. Out of the 35 cover crop species/cultivars tested, at least one of the SCN populations reproduced on seven crops/cultivars but did not reproduce on the other 28 crops/cultivars. Out of these seven crops, only white lupine (Lupinus albus L.) was a suitable host (FI ≥ 10) for both SCN populations in all the experiments, while others showed varied responses from poor host to suitable host for the SCN populations. The host crops were from the family Brassicaceae or Fabaceae, while all the crops in the Linaceae or Poaceae family tested were non-hosts. The non-host crops can be planted in SCN-infested fields without the concern of increasing SCN populations, while poor hosts with low female index should be evaluated for effects on reduction of SCN numbers in the fields before they are used as cover crops in a soybean cropping system.