Hardwood stem cuttings of bougainvillea (Bougainvillea spectabilis Willd) consistingof two to four leaves were treated with triadimefon (triazole derivative) in the form of foliar sprayat 50 ppm and 100 ppm, while the control plants were treated with water spray. The (treatment)plants were irrigated once in two days, once in four days and the control plants were irrigateddaily. The experiment was conducted at the Al Maqam campus of the U.A.E. University, Al Ain.The experimental design was completely randomized with the two factors being irrigation andchemical treatment, consisting of nine treatment combinations, replicated three times. The relativewater content (RWC) in both concentrations was similar, while the control plants showed highplant-water content. Photosynthetic pigments viz., Chlorophyll a, increased with increasingconcentration of the chemical, while the Chlorophyll b and Total Chlorophyll showed significantdifferences with different treatment combinations of irrigation frequencies and triadimefontreatment. Combination of triadimefon with irrigation frequencies produced sun-type chloroplastsand increased chlorophyll accumulation. Compared with the control, the stomata from the abaxialepidermal peels in the triadimefon treated leaves were sunken, narrow and appeared partiallyclosed. Both triadimefon treatments increased the number of trichomes compared to the leafsamples of control plants. Formation of epicuticular wax in treated plants was noticed, which wasprobably formed to act as a barrier against water loss. The results of the present study may add tothe plant growth regulatory effects data published previously on the synthesis of photosyntheticpigments, and other growth responses conducive for protection against moisture stress.
Triadimefon, moisture stress, chloroplast, trichomes, sunken stomates