PACLOBUTRAZOL CAN REDUCE THE NEGATIVE EFFECTS OF SALINITY ON REPRODUCTIVE GROWTH, YIELD AND FRUIT QUALITY OF STRAWBERRY PLANT

Strawberry plants (Fragaria × ananassa Duch.) are very susceptible to salinity. In order to investigate the interactive effects of paclobutrazol (PP₃₃₃) and salinity on flowering, yield and fruit quality of strawberry plants, three levels of NaCl [0, 5, 10 mM] were incorporated into the nutrient solution and four levels of PP₃₃₃ [0, 10, 20, 30 mg/L] were sprayed on the plants. PP₃₃₃ application caused reduction in inflorescence length, but increased inflorescence and flower number. Salinity reduced number of achenes per fruit. However a foliar application of 10 mg/L of PP₃₃₃ reduced the effect of salinity at 10 mM NaCl salinity and significantly increased the number of achenes per fruit. PP₃₃₃ at 30 mg/L completely overcame any negative effects of 10 mM NaCl salinity on fruit yield while increasing fruit total soluble solids (TSS). The highest level of PP₃₃₃ (30 mg/L) resulted in reduced titratable acidity (TA) on salt-treated (5, 10 mM) plants. The ratio of TSS/TA tended to increase with increased application rates of PP₃₃₃. Salinity resulted in reduced vitamin C, but applications of 20 mg/L of PP₃₃₃ significantly increased vitamin C in both levels of salinity (5, 10 mM).