Effect of 2, 4-D sprays on the anatomical characters of some weeds

Abstract

Seedlings ofAchyranthes aspera L.,Cassia tora L., andRuellia tuberosa L. were sprayed with 100, 200, 400, 600, 800 and 1,000 ppm of 2, 4-D solution. The herbicide induced proliferation of cambium in the hypocotyl and stem ofA. aspera, cambium, xylem elements and tannin cells in the hypocotyl and stem ofC. tora and cambium and phloem in the hypocotyl and stem ofR. tuberosa. It had a lethal effect on the cortex, endodermis, phloem, xylem and pith of the petiole ofC. tora, on cortex, cambium and phloem in the hypocotyl and stem ofA. aspera and on cortex, endodermis, cambium and phloem in the hypocotyl and stem ofR. tuberosa. InR. tuberosa proliferation of pericycle in the root was also seen in the form of huge masses of cells, limited in length. Endodermis and cortex from this region of proliferation had ruptured. Adventitious roots developed from the hypocotyl and internodes inR. tuberosa and only from internodes inC. tora, may be due to proliferation of phloem and cambium inR. tuberosa and of cambium inC. tora, respectively. Small protuberances on the stem region ofA. aspera were also ascribed to the proliferation of cambium. Lysigenous cavities were found in the cortex and pith of the stem ofA. aspera treated with 2, 4-D.