Growth and cation uptake in turf-type tall fescue ( <i>Festuca arundinacea</i> Schreb.) are affected by low light intensity

Summary Low light intensities adversely affect the growth of tall fescue ( Festuca arundinacea Schreb.). The objective of this experiment was to understand the effects of low light intensity on tiller/leaf appearance rate, and on cation uptake. Single plants of two tall fescue cultivars, ‘Tar Heel II’ and ‘Wolfpack’, were established in plastic tubes and maintained in a greenhouse. The plants were subjected to shade treatment by covering with black knitted polyethylene cloth that allows 30% of full light to pass through without changing the light quality. Shade treatment reduced the biomass and stomatal density of tall fescue but did not affect stomatal conductivity. There was a greater reduction of root biomass (66%) than shoot biomass (47%). Shaded tall fescue also had a lower leaf appearance rate (0.132 leaf d -1 ) than that in full light (0.139 leaf d -1 ), which decreased to 0.065 leaf d -1 and 0.070 leaf d -1 , respectively, over 4 weeks. Similarly, tiller appearance rate in shade was 0.36 tiller d -1 , as compared to 0.42 tiller d -1 for full light, which decreased to 0.11 tiller d -1 and 0.18 tiller d -1 , respectively, 4 weeks after shade treatment. Shoot potassium concentration showed no difference in plants grown under shade or full light. Our results indicated that Fe content increased in leaves under shaded conditions. However, the optimum Fe content for managing tall fescue under such conditions is still unknown. Further research on the soil application of Fe and phytosiderophores to enhance shade tolerance is recommended.