Control of Using or 4-Hydroxybenzyl Alcohol with the Trap Crop or the Biofumigant Seed Meal Extract.

The pale cyst nematode is a highly specialized, economically important pest for potato production. The specialized hatching requirements, ability to adapt, and the loss of effective control strategies such as methyl bromide fumigation increase the challenge to eradicate in Idaho. Without a suitable host, this nematode can remain dormant as encysted eggs in soil for up to 20 years. In this study, we first demonstrated that seed meal extract (SME) or 4-hydroxybenzyl alcohol (HBA), under laboratory and greenhouse conditions, enhances egg hatch rate when exposed to potato root diffusate (PRD). This hatch rate enhancement in the presence of PRD is speculated to be due to an increase in egg-shell permeability. We then tested the efficacy of (i) following prior treatment with SME (0 and 4.48 t/ha) or HBA (0 and 0.12 t/ha) and (ii) SME (0, 0.14, 0.56, and 1.12 t/ha) following HBA treatment (0 and 4.48 t/ha) on egg viability, hatch rate, and reproduction of encysted eggs. alone reduced the number of encysted eggs compared to the nontreated control by up to 67%, indicating that this trap crop triggered eggs to hatch. When combined with SME or HBA, significantly reduced egg count, hatch rate, and viability more than alone. The combination of with HBA or SME eliminated reproduction on the susceptible potato. All the tested rates of SME alone or with HBA reduced egg hatch rate, viability, and reproduction compared to the nontreated control. Combining HBA and SME further significantly reduced egg hatch rate, viability, and reproduction than those rates of SME alone.