Study On Heat-tolerance And Unicomazole Seed Soaking Physiological Effects Of Tall Fescue Varieties

Tall Fescue (Festuca arundinaces Schreb.) has been widely used in the playground, courtyard and etc., for its fresh green colour, long-green periods and strong adaptability to the enviroment. However, although it has the strongest heat tolerance among the cool-season grasses, It still has difficulty in overcoming summer stress in transitional areas including Nanjing. Since Tall Fescue growth fast, Clip costs the most of the money and manpower during the turf management. The paper compared the heat tolerance and growth characters of 14 Tall Fescue varieties in Nanjing across summer, and chose five representative varieties of them to study the relationship between the turf quality and their physiological characters , the heat tolerance mechanism were also discussed. Moreover, uniconzole were used to seed soak two Tall Fescue varieties which differed in growth speed, then seeding rate ,drawf effects and physiological reactions to high tempetature stress were studied..According to the semi-lethal time, which derived from the Sigmoidal electrolyte curve, Heat tolerance of the 14 Tall Fescue varieties were compared, it showed, TF01 and TF05 had the strongest heat tolerance; then it comes to TF03, TF13, TF16, TF06, TF07, TF19 and TF14 and TF08; TF11, TF10 and TF18 were the were weak in heat tolerance; TF12 were the weakest.The study on growth characters of Tall Fescue during summer turned out, the 14 Tall Fescue varieties could be classified into three categories: TF07, TF08, TF10 and TF18 belonged to the first category, they present high quality before summer stress for they had dark green leaves, high coverage and density, however, from August their coverage and density reduced to the lowest, and their turf quality remained to be the worst on both August and September. So they were weak in heat tolerance. TF06, TF11, TF12, TF13, TF14, TF16 and TF19 belonged to the second category, they grow well before summer stress, and they had worse quality for only one month. So they belonged to the mid-heat-tolerance varieties. TF01, TF03 and TF05 belonged to the last category, their turf quality were listed to the best during the whole summer, especially, TF03 had worst...