Microorganisms impacting production of forage crops

Forage365 is an initiative to enhance forage production by developing year round grazing for the southern Great Plains (Oklahoma and Texas). Using a systems-based approach, perennial forages will be integrated to complement the warm season grasses and winter annuals currently in use. In addition to targeting and improving the pillar species, alfalfa, Bermudagrass, tall fescue, and winter wheat, we are also evaluating the microorganisms associated with these forage species. Microorganisms can greatly impact production of forage crops, either as beneficial or pathogenic microbes. Beneficial fungal symbionts (Sebacina and Epichloë species) and plant growth promoting bacteria are being evaluated to lower agricultural inputs, such as fertilizer, and to provide protection against some biotic and abiotic stresses. The success of tall fescue is often attributed to a fungal seed borne symbiont called Epichloë coenophiala that provides a selective advantage to its host. Sebacina and plant growth promoting bacteria can dramatically increase yield under environmentally challenging conditions. In contrast to the beneficial symbionts, pathogens can dramatically reduce yield and stand longevity. The root pathogen Phymatotrichopsis omnivora is considered a ‘natural born killer’ of dicotyledonous plants, including alfalfa, cotton and fruit and nut trees. This pathogen is endemic to southwest USA and is often considered the main cause of the limited alfalfa production in the southern Great Plains. Unfortunately there are no known mechanisms of disease resistance but recently the fungicide flutriafol has been successfully used to protect cotton and studies are ongoing for use with the perennial crop alfalfa. To better understand how this disease spreads in alfalfa, aerial imaging is being used to identify areas of stand loss, follow the seasonal disease progression and determine the cost of production losses caused by P. omnivora.