Effect of bio-stimulants on growth and chemical composition of mahogany seedlings grown under treated wastewater (TWW)

A pot experiment was carried out to study the effect of treated waste water (TWW) on mahogany seedlings and the role of bio-stimulants in alleviating the harmful impacts, using –6- months' old seedlings.  The TWW was used in 3 types coded as 75%WW/25%PW, 50%WW/50%PW and 25%WW/75%PW, according the ratio between treated wastewater (WW) and potable water (PW).  All seedlings grown under the different types of TWW treatments were sprayed with some bio stimulants. The results revealed that irrigating mahogany seedlings with 25WW/ 75PW, significantly increased plant height, improved the formation of leaves, fresh weight leaves, 25WW/ 75PW increased total indoles whereas using 75WW/25PW or 50WW/50PW, for irrigation produced thicker and heavier FW of stems. FW of leaves with 50WW/50PW gave the heaviest fresh and dry weights of leave and roots diameter, total phenols, free proline and total soluble sugars. The treatment of 75WW/25PW formed significantly longer roots, both 75WW/25PW 0r 50WW/50PW, insignificantly increased fresh weight of roots. All bio-stimulants significantly increased plant height and seaweed extract, salicylic acid and Pot. silicate were the most effective. PS treatment exhibited the thickest stems.&nbsp