THE INFLUENCE OF ADDING MORPHACTIN TO THE HERBICIDAL ACTION OF BROMOXYNIL ON THE GROWTH, CHEMICAL COMPOSITION AND ANATOMICAL STRUCTURE OF CHARD PLANT

Two pot experiments were carried out during the two successive seasons of 2001/2002 and 2002/2003 in the green house of the National Research Centre, Dokki to investigate the effect of spraying Bromoxynil at the concentrations of 0, 1.00, 1.25 and 1.50 mg/l and Morphactin at concentration of 0, 20, 40 and 80 ppm alone or in combination on the growth after 30 and 60 days from spraying Beta vulgaris, L. var Folliosa A. SF. Leaf beet (Chard). Chemical composition was determined after 60 days from spraying.
                The anatomical studies were performed in the leaves of three months old plants treated with the lower concentration of  Bromoxynil (1 mg/l) or Morphactin (20 ppm) as well as plants treated with the combination between (Morphactin 40 ppm + Bromoxynil 1.00 mg/l), since the high concentration of both substances induced complete eradication of Chard.
                Combined treatment 40 ppm Morphactin and 1.00 mg/l Bromoxynil increased thickness of midvein, but decreased number of vascular bundles. While, thickness of the leaf at its marginal portion was not affected. At the same time, such treatment decreased thickness of the upper and lower epidermis. While, palisade tissue thickness was increased. However, spongy tissue was not affected.
                Morphactin and Bromoxynil induced also decreases in N, P and K with the increase in concentration. While, Zn and Mn were increased with the increase in concentration of both Morphactin and Bromoxynil.
                These results showed clearly that adding low concentration of Morphactin increased the efficiency of the herbicidal properties of Bromoxynil.