Fig. 2. (A) Temperatures measured with thermocouples in three dosimeter packets placed above or in a tall fescue canopy; and (B) relationship of survival (S) of E. coli strain CSRO6 in dosimeter packets on chilled agar or on wooden sticks to UV-B dose (D) measured with a YES broad-band radiometer during full sunlight exposure. All measurements were made on DOY 183, 1997. In (A), packets were mounted on wooden sticks. At ‘0’ time (1107 h CST), packet 1 was placed above the canopy while Packets 2 and 3 were placed on the soil surface. At time ‘a’, the positions were interchanged. At time ‘b’ all of the packets were transferred to an ice chest. In (B), exposure began at 1200 h CST and sets of packets were removed from sunlight at 5-min intervals.