EFFECTS OF FROST AND FROST PROTECTANTS ON TALL FESCUE SEED PRODUCTION

A study of the effects of frost on 'Grasslands Roa' tall fescue (Festuca arundinacea Schreb.) showed that tall fescue reproductive tillers are particularly sensitive to frost damage at ear emergence and during anthesis.Two air frosts (-2 and -5-degrees-C) were applied to tall fescue reproductive tillers for one 6-h cycle at either ear emergence, anthesis, or 4, 6, or 8 days after anthesis. The -5-degrees-C frost destroyed all seed heads. A single exposure to -2-degrees-C frost reduced seed yield by nearly 50% but had relatively less effect on seed weight and germination, provided frost did not occur at ear emergence or anthesis. Developing seed 6 and 8 days old was less susceptible to -2-degrees-C frost, despite some decrease in seed yield and a slight reduction in the rate of germination. Two frost protectants used in the study, an ethylene oxide condensate (Teric) and a cupric hydroxide (Kocide 101), did not prevent frost damage from occurring, but the seed yield reduction after the -2-degrees-C frost was less in seed heads protected by Kocide 101 (P < 0.05) and Teric (P < 0.10) than in untreated seed heads.