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Abstract - 96 - VI • SUlOlARY Experiments were conducted under laboratory conditions in plant protection Dept. and under field conditions in the experiment station of the faculty of Agricultur ~ Moshtohor, Zagazig University. Kena! Hibiscus cannabinus variety Giza 3 was used to study the side effect of Borne insectioides (endrin, dimethoa te, mephosfolan, profenofos, chlorpyrifoa, methomyl, cypermethrin and fenvalerate. A soil free to a large extent from pesticide residues was used in the laboratory experiments. Four insecticides were used under laboratory conditions to study the side effect of soil polluted by the above insecticides on germination, root and stem growth and on the chemical contents of kenai plants. The above insecticides were used at the rate of 10, 20, 40, 60, 80 and 100 ppm, as active ingredient. Treated soils were placed in pots and were cultivated with 10 seeds of kenaf. Each pot was irrigated with 75% of soil field capacity. The pots were weighed every two days and the loss in water was compensated. After 10 days the percentage of germ.tnation was recorded. After 30 days the root and stem length were measured. Also the symptoms of damage to pla.nts were re corded. Por 0’. - 97 - chlorophyll and carotenoids determinations 0.4 gm. samples from the leaves were used. Samples were extracted by grinding in 85% aqueous acetone and a small amount of Os. C03 were added to acetone solution before grinding. The total chloroplast pigments were ditermined by spectrophotorD3ter. The chloropla at pigments were calculated according to the equations mentioned by Arnon 1949 and Abdel-Haffez 1981. Total phosphorous, potassium, total sugars (reducing and non reducing sugars), and total nitrogen were also determined. Under field conditions, kenaf was cultivated in . plots 1/200 feddan. The area consisted of nine treatments with three replicam for each. Dimethoate, profenofos, chlorpyrifos, mephospholan, endrin, methomyl, cypermethrin and fenvalerate were tested at the rate of 1.0 kg, 2.0 kg, 2.1 kg, 2.25 kg., 3.75 kg, 1.35 kg, 0.3 kg, and 0.6 kg active ingredient respectively. Plants were treated with insecticides just before presowing irrigation. The standard agricultural treatments were followed. After 9 weeks, samples were taken to measure root and stem length. Also the symptoms of insecticide damage on plants were recorded. - 98 - Same methods used before to deterBine chlorophyll, phosphorous, potass1um,total sugars and total nitrogen were conducted in field experiments. After the crop maturity the straw and seeds were weighed. Results indicated that endrin, profenofos, methomyl and chlorpyrifos decreased the percentage of germination. Generally all the above insecticides decreased root growth Dwarfing was evident in all treatments. Chlorpyrifos and methomyl were the most harmful insecticides tested for root and stem growth. Endrin was the only insecticide which increased the stem length at all concentrations tested. Profenofos seems to be less effective than methomyl and chlorpyrifos. The phytotoxic effects appeared clearly in the methomyl treatments. It appeared in the form as deleterious effects on the green parts. It took the form of a marginal browning of the edges of plant leaves. Chlorpyrif’os retarted the appearance of the 4th. and 5!!!. leaf. Endrin increased chlorophyll.!!.and .2 at all concentrations testedo Metho~l and chlorpyrlfos decreased chlorophyll ~ and ~’ while profenofos increased chlorophyll k and decreased chlorophyll ~ at doses more than 60 ppm. --~-» .. _--------------------------~ - 99 - Methomyl and chlorpyrifos also reduced carotenoida at all concentrationsteated, while endrin increased carotenoids only at doses more than 20 pp~. Low doses of profenofos (less than 40 ppm) increased carotenoids. All insecticides tested increased the total soluble sugars except the high doses of chlorpyrifoB (up 40 ppm). While endrin increased the reducing BUgar, it inhibited the non reducing sugar at all concentrations tested. Methomyl was the only insecticide Which increased both reducing and non-reducing sugar. Profenofos increased the redUcing and non-reducing sugar only at high and low dosages only, while at 20-60 ppm the sugar content was inhibited ChlorpyrifoB increased the reducing sugar at high and low dosages while the same dosages decreased the non-reducing sugar. Endrin at all concentrations reduced the nitrogen contents. Chlorpyrifos at all concentrations tested increased nitrogen. Low concentration of methomyl and high concentrations of profenofos increased nitrogen content. All insecticides tested at all concentrations increased potasium content except low doses (10-20 ppm) of methomyli |