Mint is grown in northern California in the Fall River/Big Valley and in the Klamath Basin. Production of this specialty crop is important to the local economies of northeastern CA. The short frost-free period (1000-m elevation) limits crops which can be grown. Mint thrives with long warm days and cool nights and is an ideal fit. Marketing and use of mint oil is highly sophisticated as oil from various sources is mixed for the end-product and critiqued with the scrutiny given to fine wines. Mint is stressed by spider mites (Tetranychus spp.) and by a complex of soil-borne insects lead by the mint root borer (Fumibotys fumalis). Considerable research has been conducted on mint in the Pacific NW. However, the results of these studies did not appear to completely fit California conditions. Growers and consultants lost confidence in these results and it was obvious that adaptive studies needed to be conducted.
Spider Mites: The tenets of the Oregon management system for mites are population assessment, estimation of yield impacts, and effective use of appropriate management tactics (miticides and releases of predatory mites). Our studies were designed
- to develop treatment thresholds
- to design efficient sampling methods for mites
- to investigate the efficacy of reduced risk miticides including biological materials
- to study the use of predatory mites for the management of spider kites in mint
Mint Root Borer: A degree-day model was developed in Pacific NW to assist in timing population events. This model and reduced risk insecticides were evaluated in California.