he effects of paclobutrazol on physiological and biochemical changes in Patumma cv. Chiang Mai Pink during water
stress were investigated by using 0 (control) and 1,500 ppm (treatment) of paclobutrazol. Paclobutrazol was applied once as
soil drench. Two weeks later, water withholding was started for 40 days. Soil water content, relative water content (RWC) in
the leaves, plant height, dry weight/plant, chlorophyll a and b contents, and proline and malondialdehyde (MDA) contents in
leaves were evaluated every 10 days for 40 days after the start of water withholding. The results showed that the dry weight
and RWC in the plants treated with paclobutrazol were higher, while the reduction of plant height, proline, and MDA contents
were lower than the control during water deficit. This study indicates that paclobutrazol increased the tolerance of Patumma
plants to water stress.