A pot experimental study was carried out during the season of 2019/2020. The experiment was a factorial involving 3 factors (1) H humic acid H0 and H1 added to soil at 0 and 2 g L -1 ; (2) Boric acid spray B : B0, B1 and B2 solutions of 0 , 2 and 4 mg L -1 respectively (3) PP333 Paclobutrazol P0 , P1 and P2 foliar solution of 0, 20 and 40 mg L -1 respectively (18 treatments 2H x3Bx3 PP333). The heaviest dry weights of leaves/plant was gained by H and 20 ppm pp333-sprayed plants . Applied

more »

... nts, particularly PP333 at 20 , 40 ppm and B at 2 mg L -1 , among these anatomical features were the most important ones, i.e., thickness of leaf midrib, length and width of vascular bundle, phloem and xylem tissues and number of xylem vessels in vascular bundle as well as the leaf blade thickness.