الفهرس 
coverOnly 14 pages are availabe for public view
 |  | from | 136 |  |  |
| | | from | 136 | | |
Abstract
A greenhouse experiment was carried out 2006/2007 and 2007/2008 growing seasons to determine the potentials and elimination efficiency of some natural additive materials; sugarcane bagasse, rice straw and gypsum on leaching of organic chemicals that could contaminants the groundwater. Also, to study the side effect of the additive materials on plant growth. br 1. Organic chemical leaching to the groundwater: br The results showed that the additive materials affected extensively the leaching of tribenuron-methyl (TBM) and cadusafos through the tow tested soil types; sandy clay and sandy soil. Rice straw and sugarcane bagasse additive materials highly reduced leaching of TBM and cadusafos than gypsum. Rice straw treatment achieved the highest average reduction percentage (-33.8 and -43.1%), than sugarcane bagasse (-18.1 – -29.6%) when compared with TBM treatment alone in sandy clay and sandy soil, respectively. Also, Rice straw treatment achieved the highest average reduction percentage (-44.4 and -52.8%), than sugarcane bagasse (-36.9 and -44.5%) when compared with cadusafos treated alone in sandy clay and sandy soil, respectively. br 2. Organic chemical accumulation in different soil types: br Results revealed that all additive material obviously affected TBM and cadusafos concentration in soil and this effect varied according to additive material type, concentration, soil type and depth. br 2. 1. Tribenuron-methyl herbicide: br The average decrease/increase % of each material dose, it illustrated that sugarcane bagasse, rice straw and gypsum treatments at the dose of 300, 300 and 160 kg/fed. showed the highest average reduction % of TBM residues reaching, -56.5%, -50.0% and -50.7%, respectively. Also, it illustrated that sugarcane bagasse was the most effective mobile and reducing material for TBM residues in the treated soil reaching -47.7%, followed by rice straw (-41.5%) and gypsum (-38.3%). As in sandy clay soil, average decrease/increase % of each material dose illustrated that in both of sugarcane bagasse, rice straw and gypsum treatments at the dose of 300, 300 and 160 kg/fed. showed the highest average reduction% of TBM residues reaching, -54.3, -12.9 and -36.9%, respectively. Total average decrease/increase % indicated that sugarcane bagasse straw was the most effective mobilize and reducing material for TBM residues in treated soil reaching -42.2%, followed by gypsum (-30.9%) and rice straw (-12.0%). br 2. 2. Cadusafos nematicide: br As the same tribenuron-methyl as, the cadusafos average decrease/increase % of each material dose showed that in both of sugarcane bagasse, rice straw and gypsum treatments, the dose of 300, 300 and 160 kg/fed. caused the highest average reduction% of cadusafos residues being, -39.6%, -31.5% and -53.7%, respectively. Also, total average decrease/increase % indicated that gypsum was the most effective mobile and reducing material for cadusafos residues in treated soil reaching -46.4%, followed by sugarcane bagasse (-35.9%) and rice straw (-30.0%). br As in sandy clay soil, the average decrease/increase % of each material dose illustrated that in both of sugarcane bagasse, rice straw and gypsum treatments at the dose of 300, 300 and 160 kg/fed. showed the highest average reduction% of cadusafos residues reaching, -49.5, -47.9 and -53.0%, respectively. Also, total average decrease / increase % indicated that gypsum was the most effective mobilize and reducing material for cadusafos residues in the treated soil reaching -45.7%, followed by sugarcane bagasse (-41.1%) and rice straw (-33.8%). br 3. The side effect of the additive materials on the plant: br 3. 1. Glutathione S-transferase activity (GST): br Mean results of sugarcane bagasse and gypsum additive materials treated alone or in combination with TBM and/or Cadusafos during the 1st and 2nd seasons showed insignificant effect on GST activity of the treated plant, being 93.99 and 131.46 IU/mg protein and 91.95 and 123.37 IU/mg protein comparing to the untreated plant (91.06 and 123.86 IU/mg protein). Meanwhile, rice straw significantly increased GST activity during the 1st and 2nd growing season reaching 116.89 and 188.99 IU/mg protein, respectively, compared with the untreated plant. Also, sugarcane bagasse and rice straw showed its peak at the rate of 150 kg/fed. at the 1st (109.86 and 146. IU/mg protein) and 2nd (158.13 and 305.67 IU/mg protein) growing season, respectively. In the contrary, Gypsum treatment effect was decreased gradually with increasing dose rate, reaching its peak at the rate 40 kg/fed. being, 106.03 and 145.18 IU/mg protein during the 1st and 2nd growing season, respectively. br 3. 2. Chlorophyll contents: br 3. 2 .1. Chlorophyll (a) contents: br Data showed that chlorophyll (a) of wheat leaves varied significantly according to the applied pesticide, additive materials type and dose during the two growing seasons. Sugarcane bagasse and rice straw when it was applied in combination with TBM or cadusafos, increased chlorophyll (a) content significantly and the increasing rate was positively correlated with increasing rate of rice straw reaching its peak at 4.0 g/pot. br Data of gypsum + TBM or cadusafos treatment illustrated that chlorophyll (a) content of wheat leaves decreased significantly after 7, 14 and 21 DFA, during the first and second growing seasons comparing with TBM or cadusafos treatment. br 3. 2 .2. Chlorophyll (b) contents: br Results illustrated that chlorophyll (b) of wheat leaves changed in parallel with chlorophyll (a) and its content differed significantly according to the applied pesticide, additive material type and dose during the two growing seasons. Sugarcane bagasse in combination with TBM or cadusafos significantly decreased chlorophyll (b) than pesticide when it was applied individually at the different periods. Such effect was positively correlated with increasing sugarcane application rate during the two growing seasons. The addition of cadusafos to sugarcane bagasse led to an increase in chlorophyll (b) content over the untreated material and /or TBM. On the contrary with sugarcane bagasse, rice straw treatments when applied in combination with TBM or cadusafos, increased chlorophyll (b) content significantly and the increasing records were positively correlated with increasing the rate of rice straw. Gypsum + TBM or cadusafos treatment showed significant reduction in chlorophyll (b) content of wheat leaves after 7, 14 and 21 DFA, during the first and second seasons compared to untreated. br 3. 2 .3. Chlorophyll a/b ratio: br Ratio of chlorophyll a/b showed that all treatments showed no great differences on chlorophyll a/b ratio according to the applied pesticide type, additive material type and dose during the two growing seasons. br Sugarcane bagasse alone or in combination with TBM and cadusafos increased chlorophyll a/b ration remarkably, after 7 DFA. Rice straw combined with TBM showed a remarkable increase in a/b ratio being 10.02% in relative to TBM treatment after 14 DFA. Gypsum treatments alone or in combination with TBM and cadusafos increased chlorophyll a/b ratio remarkably after 7 DFA, while showed a remarkable reduction in chlorophyll a/b ratio after 21 DFA, at the 1st season being -10.04%. At the 2nd season, gypsum +TBM treatment increased chlorophyll a/b ratio after 14 being 11.0% relative to the TBM treatment. br 3. 2. 4. Total chlorophyll contents: br Data showed that the change of total chlorophyll of wheat leaves synchronizes with the variation in chlorophyll (a) and chlorophyll (b) according to pesticide type, additive material type and dose during the growing two seasons. The results showed that when TBM was applied alone, total chlorophyll decreased significantly and it was less than the untreated plant after 7, 14 and 21 DFA during the 1st and 2nd growing seasons. Dissimilarity, cadusafos treatment increased total chlorophyll significantly during all sampling time. When sugarcane bagasse was applied in combination with TBM or cadusafos, total chlorophyll decreased significantly and it was less than when the pesticide was applied individually at all sampling times. In rice straw treatments + TBM or cadusafos treatment data showed that total chlorophyll content of wheat leaves varied significantly according to rice straw rate and sampling time. Total chlorophylls decreased significantly after 7 DFA, while it showed significant increase after 14 and 21 DFA, comparing to TBM or cadusafos treatment. Gypsum + TBM or cadusafos treatment showed significant decline in total chlorophyll content of wheat leaves after 7, 14 and 21 DFA, during the two growing seasons than that resulted -#102;-#114;-#111;-#109; TBM or cadusafos treatment. br 3. 2. 5. Carotenoids contents: br Data showed that wheat leaves carotenoids varied significantly in relation to the applied pesticide, additive material, and its dose during the growing two seasons. In sugarcane bagasse combined with TBM or cadusafos treatments, carotenoids decreased significantly less than when the pesticide was applied individually at 7 and 21 DFA. The decreasing effect was positively correlated with increasing sugarcane application rate during the two growing seasons. Also, data showed that the addition of TBM significantly increased carotenoids content more than the untreated material and /or cadusafos at the different sampling time; 7, 14 and 21 DFA. Opposite to sugarcane bagasse, rice straw treatments when it was combined with TBM or cadusafos, increased carotenoids content significantly and the increasing numbers were positively correlated with increasing rice straw rates. Gypsum + TBM significant decreased carotenoids content than the TBM treatment after 7 and 21 DFA., while Gypsum + cadusafos results showed significantly decreased. br 3. 2. 6. Fresh weight: br Results of fresh weight showed that all additive materials treatments increased the fresh weight during the two growing seasons significantly. Rice straw was the most effective treatment showing the highest increasing effect at 300 kg/fed. (7.0 and 5.52 g/plant) followed by sugarcane bagasse at 225 kg/fed. (6.25 and 4.78 g/plant) and gypsum was the lowest showing the highest effect when applied at rate of 40 kg/fed. (5.97 and 4.53 g/plant) at the first and second season, respectively. br 3. 2. 7. Dry weight: br Data of wheat dry weight illustrated that all additive materials treatments showed significant effect on treated plant dry weight during the two growing seasons. Rice straw showed the highest increasing effect reaching its peak at 300 kg/fed. (1.47 and 1.87 g/plant) followed by sugarcane bagasse at 225 kg/fed. (1.27 and 1.47 g/plant) and gypsum when applied at 40 kg/fed. (0.92 and 0.72 g/plant) at the first and second season, respectively. br -#102;-#114;-#111;-#109; the above mentioned results it could concluded that all additive materials treatments showed significant effect on TBM and Cadusafos leaching in soil and/or groundwater contamination. br Rice straw was the most effective treatment which reduced leaching of the treated pesticide at the rate 300 kg/fed followed by sugarcane bagasse and gypsum. Also, rice straw treatment was significantly increased chlorophylls (a, b and total) after 7, 14, and 21 DFA comparing with gypsum treatment. Rice straw significantly increased GST activity and showed the highest increasing effect on fresh weight and dry weight.