Registration of ‘DeSoto’ Tall Fescue

'DeSoto' tall fescue (Festuca arundinacea Schreb.) (Reg. no. CV-59, P1 583747) was developed by the Mississippi Agricultural and Forestry Experiment Station and released in June 1994. DeSoto was tested under the experimental designation, MSF-77-1. DeSoto is an open-pollinated population derived from plants selected for forage yield potential and persistence from an old, unmanaged stand of tall fescue located near Starkville, MS, in the spring of 1977. This selected population was designated MSF-77-1. Yield trials indicated that MSF-77-1 had good forage yield potential in Mississippi; however, it was discovered that almost 100% of the plants contained the fungal endophyte Acremonium coenophialum Morgan-Jones & W. Gams, the agent involved in summer syndrome and poor animal performance of cattle grazing tall fescue pastures. In 1983, MSF-77-1 was subjected to a single cycle of mass selection for freedom from endophyte. Seed of MSF-77-1 that had been stored at ambient temperature for 2 yr was grown out, and leaf tissue from 6-wk-old seedlings was stained and examined for the presence of the endophyte. Plants with no viable endophyte were transplanted to an isolation block and allowed to random mate. Endophyte-free seed of MSF-77-1 was harvested from this block in the spring of 1985. All subsequent yield evaluations of MSF-77-1 were carried out with endophyte-free seed. DeSoto matures earlier than 'Kentucky 31', but slightly later than 'Fawn'. DeSoto headed 4.7 d earlier than Kentucky 31 and 3.4 d later than Fawn in 1992 at MSU. DeSoto underwent anthesis 4.3 d earlier than Kentucky 31 and 6.9 d later than Fawn in 1991 at MSU. DeSoto reaches peak production earlier in the spring than Kentucky 31 and, thus, produces higher yields early in the spring during the critical period when forage is often in short supply. DeSoto tall fescue has shown good forage dry matter production potential in trials since 1977 throughout the southeastern USA. Dry matter forage yields of DeSoto have been similar to those of the cultivars, Fawn and endophyte-free Kentucky 31. DeSoto was evaluated in 14 regional (35 year-location combinations) trials from 1977 to 1993. DeSoto produced dry matter yields which were among the best-yielding entries in most trials and which were not significantly different from the highest-yielding tall fescue entry in 20 of the 35 year-location combinations. In steer calf grazing trials, average daily gain of DeSoto (0.397 kg d~') was similar to that of endophyte-free Kentucky 31 (0.399 kg d'). DeSoto has an intermediate level of resistance to net blotch [caused by Cochliobolus sativus (Ito & Kuribayashi) Drechs. ex Dastur] similar to that of Kentucky 31 and 'Alta'. DeSoto possesses a low to moderate level of resistance to crown rust (caused by Puccinia coronata Corda) and is similar to the level of rust resistance in Kentucky 31. Overall disease rating for DeSoto at Lexington, KY, in May 1988 was intermediate and was similar to Fawn and endophyte-free Kentucky 31. Data from Lexington in 1988 and 1989 indicated that DeSoto had excellent resistance to Rhizoctonia spp. DeSoto was one of the highest rated entries for resistance to Rhizoctonia in both years. Persistence of DeSoto is similar to that of other endophyte-free cultivars. DeSoto is adapted to a wide geographic area ranging from Oklahoma to Kentucky to the Gulf Coast. It is similar to Kentucky 31 in both forage production and animal performance, but tends to produce earlier in the spring than Kentucky 31. It is recommended for those areas where early forage production is desired and which may be subject to diseases caused by Rhizoctonia spp. Generations of seed increase from breeder seed shall be one each of foundation, registered, and certified. Breeder seed will be maintained by Mississippi Agricultural and Forestry Experiment Station (MAFES). Foundation seed will be produced under the direction of MAFES Foundation Seed Stocks, Box 9811, Mississippi State, MS 39762. Application (no. 9400217) has been made for U.S. plant variety protection.