Toxic Effects of the Trap Crop Solanum sisymbriifolium on the Hatch and Viability of Globodera pallida

Globodera pallida, the pale cyst nematode, is a quarantined potato pest first found in Idaho in 2006. The containment and eradication of this economically devastating pest has been the focus of control since its discovery. Globodera pallida survives for 30+ years in soil and can cause up to 80% yield loss in susceptible potato varieties. Soil fumigants have been key to eradication efforts but many have been banned. Therefore, new control methods are needed. Solanum sisymbriifolium induces hatching but limits G. pallida reproduction and can be used as an alternative control measure. However, as S. sisymbriifolium has little economic value as a crop and its seeds are largely unavailable, it has not been widely adopted by potato producers. There is evidence that this plant kills the nematode by producing toxins, although this is poorly understood. Liquid-liquid extraction of S. sisymbriifolium leaf and stem tissues by hexane and 1-butanol reduced hatch by 49.5%, and 68.3%, respectively, compared with the potato root diffusate control. Many chemicals may be responsible for this toxic effect, including steroidal glycoalkaloids produced by plants in the Solanaceae family. The discovery of novel chemistries for nematicide development would be valuable for potato cyst nematode control.