Advantages of Endophyte Infection for Irrigated Pastures of Semiarid, Cold-Desert Environments.

Little research has evaluated possible endophyte benefits to adaptation and production of grasses in the irrigated pastures of the semiarid, cold-desert environments of the western USA. Severe irrigation shortages are common; however, production demands are increasing necessitating maximizing tall fescue’s (Festuca arundinacea Schreb.) productivity when grown in sub-optimal conditions including drought, salinity, and cold temperatures. In a field study under irrigation in the Intermountain Western USA, the yield advantage to Kentucky 31 tall fescue infected with wild-type Neotyphodium over endophyte-free Kentucky 31 was greatest (over 15%) when irrigation was severely limited to natural precipitation. In an evaluation of salinity tolerance there were no significant differences in plant LD₅₀ values due to endophyte infection. In a recent study Jesup MaxQ recovered better from winter injury than Jesup E– when grown in a high-elevation cold-desert, irrigated environment. These studies suggest the need for additional research to elucidate the potential advantages of wild-type and novel endophytes for tall fescue production in irrigated environments typical of the semiarid western USA.