Effect of the trap crop, , on , , and .

The effect of the nematode trap crop was assessed against three spp., the potato cyst nematode (in Idaho), the recently described (in Oregon), and the tobacco cyst nematode (in Connecticut) in field trials. At all locations the ability of to reduce encysted second-stage juveniles (J2) in egg densities compared to fallow was considered. For , the impact of planting and termination dates of on final egg densities was also evaluated; and for , the ability of the nematode to reproduce on potato () after exposure to was determined. Encysted J2 in egg densities of all three spp. declined from 25 to 68% after trap cropping with . For , reduced final encysted J2 in egg density by 23 to 50% compared to the fallow treatment, and significantly decreased reproduction on potato after exposure to by 99 to 100% compared to the fallow treatment ( < 0.0001). For , the planting date of in May or June did not impact final egg densities ( = 0.32). Rather, percentage reduction in encysted J2 in egg density was most influenced by the length of time to which nematodes were exposed to , with 30 and 81% reduction after 6 vs 12 wk of exposure, respectively ( < 0.0001). Similar levels of nematode reduction after were observed for after 12 to 14 wk of exposure to the trap crop; density changes consisted of a 114% increase after susceptible tobacco, a 65% decrease after resistant tobacco, and an 88% decrease after compared to bare soil. In conclusion, this research demonstrates the widespread applicability of in reducing a diversity of spp. present in the USA. The effect of the nematode trap crop was assessed against three spp., the potato cyst nematode (in Idaho), the recently described (in Oregon), and the tobacco cyst nematode (in Connecticut) in field trials. At all locations the ability of to reduce encysted second-stage juveniles (J2) in egg densities compared to fallow was considered. For , the impact of planting and termination dates of on final egg densities was also evaluated; and for , the ability of the nematode to reproduce on potato () after exposure to was determined. Encysted J2 in egg densities of all three spp. declined from 25 to 68% after trap cropping with . For , reduced final encysted J2 in egg density by 23 to 50% compared to the fallow treatment, and significantly decreased reproduction on potato after exposure to by 99 to 100% compared to the fallow treatment ( < 0.0001). For , the planting date of in May or June did not impact final egg densities ( = 0.32). Rather, percentage reduction in encysted J2 in egg density was most influenced by the length of time to which nematodes were exposed to , with 30 and 81% reduction after 6 vs 12 wk of exposure, respectively ( < 0.0001). Similar levels of nematode reduction after were observed for after 12 to 14 wk of exposure to the trap crop; density changes consisted of a 114% increase after susceptible tobacco, a 65% decrease after resistant tobacco, and an 88% decrease after compared to bare soil. In conclusion, this research demonstrates the widespread applicability of in reducing a diversity of spp. present in the USA.