Fig. 4. Changes in canopy net photosynthetic rate (Pn) for creeping (CRP), colonial (CO), and velvet (V) bentgrasses under deficit irrigation in 2002 and 2003. In 2002, irrigation treatments were applied from 1 July through 18 August and then again from 13 September through 1 November. In 2003, treatments were applied from 27 June through 8 September and then again from 1 October to 1 November. Symbols indicate the irrigation treatment as a percentage of ET measurements using weighing minilysimeters. Vertical bars are LSD values (P= 0.05) within a species indicating statistically significant differences for treatment comparisons at a given day of treatment.