This investigation was carried out during the two seasons of 1999 and 2000
in the Agricultural Experiment and Research Station of Faculty of Agriculture, Cairo
University, Giza, Egypt to study the response of the anatomical structure 0 f mung
bean to different concentrations of ethrel, cycocel (CCC) and phosphorus. Transections 01 main stem revealed that treatments with ethrel at 200 and
300ppm or with CCC at 1000 and 1500 ppm enhanced the growth of stem in width by
increasing the thickness of cortex, vascular tissues and diameter of pith. Most vessels
and ray cells of secondary xylem of ethrel treated stems tended to enlarge in radial
direction more than in tangential one. Fertilization of mung bean plants with moderate
rate of phosphorus (23.25 kg P205i feddan) produced stems with higher amount of
conductive tissues and wider xylem vessels than those fertilized with 15.5 or 31 ,00 kg
P₂05i feddan I Transverse sections of leaflet blades at the median region of main stem
showed that ethrel increased sizes of midrib, vascular bundle and cells of ground
tissue, while the rate of 1000 ppm CCC increased the size of midrib and thickness
of blade (palisade and spongy tissues) the rate of 1500 ppm decreased them. Plants
received 23.25 kg P20S I feddan produced leaf blades with higher amount of tissues
than those fertilized with 15,50 or 31.00 kg P20S I feddan.