جستجوی مقالات مرتبط با کلیدواژه « آفت کش » در نشریات گروه « کشاورزی »

AbstractHoneybees (Apis mellifera) are pollinators that have great social, economic & ecological importance in agricultural production & biodiversity conservation. Despite the high environmental & economic value of this important creature, the honeybee is always exposed to destructive & damaging factors such as diseases & pesticides. Despite in recent years, mortality of honeybees were reduced due to using the subletal pesticides instead of highly toxic pesticides reduced the acute, but the adverse effects of these pesticides on honey bees should not be neglected. In general, the results obtained in this review showed that carbendazim causes disruption in the development of the nervous system & increases the length of the honeybee's growth stage. Although the bendazim is not lethal & does not cause a disturbance in the intestinal microbial composition of bees, but the pollen consumption were reduced significantly, thus causes a disturbance in nutrition & weakens the immune system, & increases the sensitivies to pathogenic agents. Therefore, beekeepers & farmers must be informed about the use of this fungicide & advised to standard use of this fungicide in agriculture.

Ants are eusocial insects of the family Formicidae and are one of the most successful insects in number and diversity. Despite their favorable impact on the ecosystem, they are sometimes regarded as serious pests due to damage to agricultural products and construction facilities. Baiting is a suitable alternative to many traditional ant control methods. In the present study, the effect of oral toxicity of fipronil, imidacloprid and borax on Tapinoma karavaievi workers was evaluated under laboratory conditions at 72, 96 and 120 hours after treatment and then the survival rate of workers treated with the LC50 of the studied compounds was compared in two weeks. According to the results, the highest oral toxicity in all three-time points was related to fipronil, imidacloprid and borax, respectively. In addition, the evaluation of the effect of pesticides on the survival of workers showed a faster control of workers treated with the LC50 of fipronil (2.46 mg ai L-1) compared to imidacloprid (32.61 mg ai L-1) and borax (2654.4 mg ai L-1). The results showed that 90% effectiveness of fipronil and imidacloprid occurred on days 7 and 11 after treatment, respectively, and it seems that 90% effectiveness of borax will probably take place in the third week after treatment. In general, the current study showed that all three studied pesticides have sufficient potential to control workers and the selection of the most suitable pesticide depends on considering the pesticide concentration, strategy of control and attention to the side effects of pesticides.

In today's world, the extensive human use of pesticides to control agricultural pests and their entry into water resources is a threat to aquatic ecosystems. In this study, Reduction of Chloriprifos organophosphate pesticide from aqueous environment was investigated by bioremediation method by Anodonta cygnea oyster as a bio filter. During a period of twelve days, three treatments with three replications were exposed to three different concentrations of pesticide, 30, 20, 15 mg / l. And indices of toxin concentration, light absorption, water pH and oyster filtration rate were measured to determine the reduction of toxin concentration. At the end of the experiment, the amount of pesticide concentration for treatments with concentrations of 30, 20 and 15 mg/L pesticides were 19 ± 0.1, 4.6 ± 0.153, 3 ± 0.133, with a reduction efficiency of 36.67%, 76.83%, 100% respectively. Percent, Light absorption rate 0.44 ± 0.001, 0.011 ± 0.002, 0.000 ± 0.000 with a reduction efficiency of 38.04%, 77.75%, 100% and a pH of 7.53, 99/7, 6/8 were estimated. Filtration rate for treatments with concentrations of 30 and 20 mg/L pesticides decreased and for treatment with 15 mg/L pesticide concentration had an increasing trend. There was a significant difference between changes in toxin concentration, light absorption miran and filtration rate at the beginning and end of the experiment (P˂0.05). Anodonta cygnea species as a suitable bioremediator for the removal of chlorpyrifos pesticides in agricultural wastewater treatment systems or contaminated natural water environments is recommended, however, further studies are needed in this area.

Borons and copper-based compounds are compounds used as pesticides and fungicides. One of the main problems of these compounds is that they easily be washed. Therefore, the main purpose of this study is to stabilize and reduce the leaching of protective materials using the encapsulation method. The encapsulation method of pesticides (boric acid and Bordeaux) was performed by natural chitosan polymer via electrospinning method and the compounds were used to treat poplar wood layers and make plywood. To evaluate the performance of the final product, physical tests (density, thickness swelling and water absorption), Fourier transform infrared spectroscopy and fungal tests were performed. The results showed that despite the low load of boric acid and pesticide, the performance of the layers was effective against fungal degradation. However, after severe leaching, their performance was reduced. The layers treated with the encapsulated pesticides retain their function as a pesticide against the fungus after washing. In general, the results showed that the technique of encapsulating pesticides can significantly reduce their leaching and on the other hand leads to maintain the function of pesticides.

Since water and soil are important components of the ecosystem ‎and their quality reduction affects the environment and agriculture, it is necessary to determine ‎the effects of pesticides on soil and water resources and determine their residual concentration ‎levels in the land. Agriculture, especially paddy fields, should be controlled and managed. ‎Therefore, the purpose of this study is to determine and evaluate the level of residual ‎concentrations of organophosphate pesticides in soil and water samples of Rudbar County and to ‎investigate their ecotoxicological status.‎

In this study, the multiplicity of 12 stations was determined using a ‎systematic random method in the paddy lands of Rudbar County. In total, 24 samples including ‎‎12 water samples and 12 soil samples were collected. Water sampling was performed in 1-liter ‎dark-colored bottles and soil sampling was performed from the surface layer according to the ‎standard method. All samples were transferred to a laboratory in a freezer containing dry ice. ‎Organophosphate pesticides were measured using the EPA 8041b standard method. All analyzes ‎were performed by gas chromatography with the mass detector in Aria Shimi Sharif Company. To ‎study the ecotoxicological status of pesticides, two databases named National Pesticide ‎Information Center and Pesticide Properties Database were used. The two databases are affiliated ‎with Oregon State University, the US Environmental Protection Agency, and the University of ‎Hertfordshire. Statistical analysis of the data included analysis of variance using one-way ‎ANOVA test, comparison of means using Duncan's test, correlation using Pearson's method, and ‎analysis of principal components using the covariance method.‎

Based on the results, 11 organophosphate pesticides were identified in water and soil ‎samples of Rudbar paddy fields. Ethion in soil and Diazinon in the water had the highest residual ‎concentrations. Sheikh Ali Tues 1 and 2 and Mirzagolband 1 stations with the values of 4.55, ‎‎3.99 and 3.49 ug/kg had the highest amount of Ethion toxin residues in the soil. In addition, ‎Sheikh Ali Tues 2, Mirzagolband 1, and Halimeh-Jan stations with 3.96, 1.71, and 1.68 ug/L, ‎respectively, had the highest amount of Diazinon pesticide in water samples. The results showed ‎that the downstream lands in the area of Imamzadeh-Hashem compared to the upstream lands in ‎Rudbar city have a higher concentration and load of pollution. The mean concentration remaining ‎in soil samples (0.987 ug/kg) was higher than in water samples (0.304 ug/L). Based on the results ‎of pesticides Diazinon, Methyl Parathion, Azinphos Methyl, Malathion, and Ethion in the studied ‎stations showed a significant difference. A comparison of the mean residual concentrations of ‎pesticides with their physicochemical and ecotoxicological properties showed that in terms of ‎potential risk and toxicity for aquatic organisms, the concentrations of BetaMevinephos, ‎Malathion, and Azinphos Methyl pesticides were 0.043, 0.573, and 0.272 ug/kg, respectively. Has ‎been very high, which has put these pesticides in a situation of high and toxic danger to aquatic ‎organisms in the region.‎

Extreme use of pesticides on agricultural land has caused environmental problems. ‎As a result, monitoring and evaluation of pesticide residues in paddy fields are very important ‎because contaminated effluents are discharged directly from rice fields into rivers, depending on ‎several factors. Due to the high levels of residual concentrations of some organophosphate ‎pesticides in the region, it is necessary to hold training courses on farmers' familiarity with the ‎dangers of pesticides to prevent, control, and reduce pollution under the supervision of experts. ‎Also, to fight non-chemically against pests, it is suggested to use the Trichogramma bee in the ‎form of Trichocart to fight the rice stem-eating worm, colored traps, and attractants in paddy ‎fields.‎

Cabbage white, Pieris brassicae (L.) (Lepidoptera: Pieridae) is an important pest of cruciferous in Iran and the world. In this study, the effect of four insecticides; hexaflumuron, spinosad, abamectin and indoxacarb on cabbage white and its parasitoid Cotesia glomerata L. was investigated The LC50 values obtained from the analysis of probit as a result of the effect of different concentrations of hexaflumuron, spinosad, abamectin and indoxacarb on the 3rd instar larvae of P. brassicae after 72 hours were (0.213, 0.298, 0.30 and 0.434) ml/L, respectively. The LC50 values obtained from the same insecticides on eggs of P. brassicae after 7 days were (0.831, 0.440, 0.267 and 0.489) ml/l, respectively. The results of the same compounds effects on parasitoid after 7 days showed that hexaflumuron and indoxacarb are the most harmful and abamectin is the least harmful for this natural enemy. The results showed that the most effective insecticides on 3rd instar larvae of P. brassicae during 72 hours was hexaflumuron. In the study of parasitization of third instar larvae of cabbage white under the influence of different concentrations of hexaflumuron, spinosad, abamectin and indoxacarb in compared with control, results showed at low concentrations of all four insecticides, there is no significant difference between control and insecticides, but there was a significant difference in higher concentrations and the mean number of third instar larvae in the control treatment increased. According to the results of this study, hexaflumuron can be suggested as a low-risk compound for parasitoid and effective against this pest.

Increasing population growth and the urgent need to increase agricultural production are closely related to the increasing use of chemical pesticides, including pesticides. Exposure to toxins has harmful effects on human health and the environment, as well as many adverse health effects. Therefore, serious measures are needed to prevent these negative effects and harms to the farmers who are exposed to it on a daily basis. Whereas the health behavior of farmers in the use of chemical pesticides is a necessity; The purpose of this study was to analyze the health behavior of farmers in Khorramabad city in the use of pesticides. The statistical population of this study included farmers in Khorramabad city, which was estimated using a sample of 150 people using Krejcie and Morgan table. The data collection tool was a questionnaire that the content validity of the research tool was confirmed by experts and its reliability was confirmed using Cronbach's alpha. The results showed that knowledge variables with 0.43, attitude with 0.60 and disease with 0.29 could directly affect the health behavior of farmers. Using mass media, virtual social networks, holding face-to-face meetings consisting of agricultural and health experts, leading and trusted farmers, using pesticide and pesticide sales centers as educational opportunities, and increasing farmers' access to some tools The need to institutionalize the healthy and safe behavior of farmers in the field of principles and methods of pesticide and pesticide management is suggested.

Pistachio is one of the most important agricultural products of the country.  It is extremely important and accounts for about 81 percent of the country's non-oil revenues. In this study, the degradation of two pesticides, metacystox and fenitrithion was investigated by ultraviolet radiation. These three pesticides are commonly used in a wide range in pistachio gardens in the country. One of the most important agricultural and plant protection tasks is to produce safe crops with residual pesticides below the MRL level. The aim of this study was to investigate the effect of UV radiation combined with the photocatalytic effect of titanium dioxide and hydrogen peroxide on the degradation of these two pesticides in pistachio products.The samples were extracted by LLE method and determinated by GC-MS. Exposur times were 30, 60,120 and 300 minutes.The results showed that the highest percentage of degradation of pesticides was related to metasystox and affected by uv / H2O2 at 38.5%. The optimum time in all trials was 300 min. UV irradiation alone at 300 min time on metasistox and fenitrothion in pistachio reduced the toxin by 24/2and 17/1, respectively.Experiments showed that degradation of the studied toxins was possible using UV irradiation and the destructive effect of UV on chemical structures was proved in experiments. Therefore, UV radiation in a specific dose can remove residues of pistachio pesticides. Combined with UV agents, hydrogen peroxide and titanium dioxide can more effectively remove contamination from agricultural products.

A Quantitative Structure–Activity Relationship (QSAR) study based on Genetic Algorithm  Multiple Linear Regressions (GA-MLR) were carried out for the prediction of the toxicity (logIC50) and the logarithm of octanol-water partition coefficient (logPow) of some carbamate derivatives as insecticides. The optimized conformation of compounds were obtained at HF/6-31G* level with Gaussian 98 software. Dragon software is used to calculate molecular descriptors. A data set of these compounds was randomly divided into 2 groups: training and test sets. The QSAR models were optimized using multiple linear regressions (MLR).The most relevant molecular descriptors were collected by Genetic Algorithm (GA) and backward regression. The best GA-MLR models are obtained using statistical parameters, such as squared correlation coefficient (R2), adjusted squared correlation coefficient (R2adj), root mean square error (RMSE) values for training and test sets. The best QSAR models are obtained based on the statistical parameters Leave-one-out (LOO) cross-validation, external test set, external validation parameters (Q2F1, Q2F2, Q2F3) and the concordance correlation coefficient (CCC) were used to quantify the predictive ability of GA-MLR models. The results showed that GA-MLR models could be used to predict the activities of carbamate derivatives.

Ecosystem Services frameworks are emerging as an approach of capturing the wider impacts of policy decisions or evaluating land use change in order to more comprehensively take into account the range of effects on the environment, and on the benefits humans receive from. The Millennium Ecosystem Assessment (MA) (2005) defines ecosystem services as ‘‘the benefits that humans obtain from ecosystems”. Costanza et al. (1997) postulated that ecosystem services comprise of ‘‘flows of materials, energy, and information” from the natural environment to the society. Yield and production for agricultural crops have been improved during the last century, however, these achievements have caused different environmental social and safety problems for human and the environment such as increase in greenhouse gases, eutrophication of rivers, lakes and other water bodies.This study aimed to evaluate environmental consequences of agroecosystems managed conventionally in three Razavi Khorasan, South Khorasan and North Khorasan Provinces. The environmental consequences of intensive agriculture were grouped into damages maid to natural resources such as water, air, soil, biodiversity and human health affected by over-consumption of chemical fertilizer, herbicide and pesticide.

Cultivated area and consumption of chemical inputs in North Khorasan, South Khorasan and Razavi Khorasan provinces during 2004-2009 were determined. Environmental impacts were calculated using six categories i.e. air (emission of greenhouse gases such as N2O, CO2 and CH4 to the atmosphere), water (quality criteria such as NO3- and pesticide concentrations in water), soil (amounts of NO3-, organic carbon, pesticides and herbicides in soil), biodiversity (losses of pastures, jungles and bee hives), human health (residues of Diazinone, Azinophos-Methyl and NO3- in some vegetables) and natural resources (losses of nitrogen fertilizers via leaching and volatilization and pesticides consumption effects) affected by chemical inputs such as fertilizers, herbicides and pesticides.

Results indicated that decreasing trends in use of chemical pesticide and herbicide were observed in different agroecosystems of Khorasan. Nitrate of water used in agricultural area was higher than allowable limit of 10 mg per liter. Residues of chemical herbicide including Diazinone and Azinophos- Methyl in irrigated water were 23.18±16.35 and 15.78±0.68 mg.kg-1, respectively. The maximum emission of greenhouse gases including CO2, CH4 and N2O were calculated in Razavi Khorasan. Nitrate concentration in the soil was higher than the critical limit. Organic carbon content in natural habitat and rangeland was higher than that in the cropland. Also, total number of honey hives was increasing but the hives for local bees were almost reaching to zero in the recent years. The maximum range of nitrate for tomato, eggplant, cucumber and spinach were 1.4, 0.75, 17.15 and 7.38% higher than allowable limit, respectively. For sugar beet upper and lower limits of nitrate were lower than the allowable limit.

Soil is a very slow forming resource, and similarly to other habitats and ecosystems, it is coming under intensifying pressures due to anthropocentric and industrial activities. Soil ecosystem services provide multiple benefits to all organisms.Nitrate concentration for leafy vegetable was higher than for kitchen garden plants. Nitrogen and phosphorus contents for soil in Razavi Khorasan were higher relative to North Khorasan and South Khorasan. Nitrogen enhanced soil carbon accumulation as it stimulates plant growth and its productivity. However, accumulation of soil carbon depends on the delicate balance between increased carbon inputs to soil from litter and enhanced soil respiration rates. Crop residues and manure are returned to the soil in traditional farming systems, improving soil ecosystem services and soil chemical, physical and biological characteristics. On the other hand, application of inorganic and chemical fertilizers to benefit crop yields often decreases the soil services as it has negative influences on soil structure, infiltration and water-holding capacity.

This study was carried out to investigate persistency of four insecticides (thiodicarb, indoxacarb, proclaim fit and lufenuron) on cotton plants and their toxicity against Trichogramma brassicae .Cotton seeds were sown under greenhouse condition and cotton plants were sprayed with insecticides . Cotton leaves were removed at one-day intervals and were kept in a rearing container with female parasitoids and host eggs. Mortality and sublethal effects of insecticides were recorded every day and their toxicity and persistency were categorized according to the International Organization of Biological Control standard. Results showed that toxicity (with up to 100% mortality) and persistency (>17 days) of thiodicarb was higher than other insecticides and was categorized as a “harmful” and at least a “moderately persistent insecticide. Indoxacarb with up to 52.8% mortality, 62.8% reduction in parasitism and 7 days persistency, was classified as a ”harmful” and “slightly persistent” insecticide. Proclaim fit with up to 37.3% mortality, 47.4% reduction in parasitism and 6 days persistency, was classified as a “moderately harmful” (Group 3) and slightly persistent insecticide. Lufenuron with up to 2.68% mortality, 60.69% reduction in parasitism and 3 days persisitency, was classified as a “slightly harmful” (Group 2) to ”moderately harmful” and short-lived (group 1) insecticide. In conclusion, because of high toxicity and long-term persistency, thiodicarb is not recommended to use in cotton field against cotton bollworm, and a 7, 6 and 3 days “waiting period” was required, respectively between spraying with indoxacarb, proclaim Fit and lufenuron and mass releasing of T. brassicae in cotton fields.

Biological pesticides have advantages to chemicals that safety to non-target organisms is of the most important ones. Slugs are parasitized or preyed by several organisms such as nematodes. In this research, integrated management of grey slug Parmacella ibera was assessed by Phasmarhabditis hermaphrodita, Metaldehyde and Fericol in field conditions in Someh Sara, Guilan Province. The treatments included: untreated, P. hermaphrodita recommended dose, P. hermaphrodita recommended dose + Fericol, P. hermaphrodita ½ dose and P. hermaphrodita ½ dose +Metaldehyde ½ dose on P. ibera assessed based on the percent of dead slugs, mean percent of damaged leaves, the number of leaves with damage symptoms and the number of plants with damage symptoms. Results showed the highest percent of dead slugs in P. hermaphrodita ½ dose +Metaldehyde ½ dose. Mean percent of damaged leaves was not significantly different among P. hermaphrodita treatments along with Fericol and metaldehyde. Results indicated that P. hermaphrodita ½ dose + Metaldehyde ½ dose treatment had considerable effect in all parameters on pest control besides a decrease in the damage.

The excessive use of pesticides in recent years and their continuation in the future may have harmful effects on the microbial population of the soil, as an indicator of soil health and one of the main components of the environment. The purpose of this study was to investigate the effect of three mostly used insecticides (Diazinon, Chlorpyrifos and Imidacloprid) on ec-ophysiological and chemical indices of soil. The experiment was conducted as a factorial in a completely randomized design which included the pesticide factor at four levels (three insecticides plus control soil) and time factor at three levels (before, three months and six months after pesticide application). Concentrations of insecticides (0.1, 1 and 0.67) mg per kilogram of soil were used for imidacloprid, diazinon, and chlorpyrifos, respectively. Some biological and ec-ophysiological indices of the soil were measured at the beginning of the experiment, three and six months after the beginning of the experiment. The results showed that, the application effect of insecticides after three months affected the biological indices including dehydrogenase enzyme activity, metabolic quotient, basal respiration, substrate-induced respiration and also organic carbon decreased compared to the control -92.2%, -46.7%, -24.7%, 15.8% and -7.61%, respectively and urease enzymes activity, microbial biomass carbon, microbial biomass nitrogen, carbon to nitrogen ratio and soil microbial quotient increased compared to control 6.67%, 32.1%, 15.6%, 16.5% and 58.9. Also, the results showed that among the insecticides Chlorpyrifos and Diazinon had the highest and the least negative effect on the indices, respectively. The application of insecticides Diazinon, Chlorpyrifos and Imidacloprid at least in the short term, had a negative effect on soil ecophysiological indices and the most sensitive indices for determining the negative impact of insecticides on the soil microbial community were the dehydrogenase enzyme activity, metabolic quotient, substrate-induced respiration and basal respiration.

Due to the fact that Tuta absoluta is one of the most important pests of tomato and causes damage, therefore to use less risk insecticides for the environment, consumers and natural enemies, in the study, the effects of, abamectin, emamectin benzoate, acetamiprid, and flubendiamide were tested against T. brassicae and T. evanescens of natural enemies of T. absoluta in laboratory conditions of Arak Agricultural Research Center in 2018. Parasitoids were reared on the angoumois grain moth, Sitotroga cerealella (Lepidoptera: Gelechiidae) eggs in the laboratory under the controlled conditions of 25 ± 1 °C, 60 ± 10% RH, and a photoperiod of 16:8 h (L: D). The comparison test of the parasitism of the two species was performed by t-test and in 10 categories in a plastic glass. LC25 of pesticides in tests were used. The experiments on LC25 effect of each pesticide on wasps survival were performed by vial assay and completely randomized design in 5 replications and in each replications 10 female wasps. Wasps were exposed to this concentration for 24 hours. Control treatment was distilled water. In order to investigate parasitism rate of lived wasps, experiments were conducted in 3 replications in each replications were 5 wasps that for 48 hours were placed exposed to150 eggs of Tuta absoluta in cylindrical containers. Completely randomized design to factoriel method was conducted. The mortality rate was recorded daily and the rate of parasitism reduction was calculated. Corrected mortality rate for abamectin, emamectin benzoate, acetamiprid and flubendiamide with host of T. absoluta were 26.67, 20, 13.33 and 13.33% for T. brassicae, respectively, and for T. evanescens 20, 20, 13.33 and 6.67 percent. The rate of reduction of parasitism in the treatment of abamectin, emamectin benzoate, acetamiprid and flubendiamide for T. brassicae were 25.12, 18.71, 13.3 and 11.81% respectively, and for T. evanescens were 24.18, 19.2, 15 and 10.84% respectively. Based on our results, flubendiamide showed selectivity and it can be used as an effective tool for integrated pest management programs of tomato leaf miner.

Considering the agricultural activities near the fish farm and water bodies, intoxication of fish is likely; thus, the aim of this study was to evaluate the effect of flonicamid intoxication on blood ions concentration and gill and kidney damage in common carp. To this, after 96 h-LC50 determination, the fish were exposed to 10% of LC50 concentration (4.3 mg / l) and after 21 days of exposure, the blood, gill and kidney were taken. The results showed that flonicamid intoxication decreased chlorine and increased potassium concentrations in fish blood, but had no effect on sodium and calcium levels. In addition, the flonicamid exposure was caused numerous damages to the gills and kidney. In the gill, the secondary lamellar edema, secondary lamellar fusion and primary lamellar hyperplasia were observed in the gill. Also, the exudate and melanomacrophage accumulation and degeneration of renal tubules were observed in kidney of the pesticide-exposed fish. The results showed that flonicamid has serious effects on the gill and kidney tissues of carp. These injuries are responsible for some of the ionic changes in fish blood. Therefore, it is recommended that this pesticide is used in farms, care should be taken to prevent the pesticide from entering the water resources in order not to threaten fish health.

This study aimed to investigate the effect of five herbicides (Tribenuron-methyl, Metribuzin, Trifluoralin, Haloxyfop-methyl, and 2, 4-D (on the soil dehydrogenase and urease activities.

The experiment was conducted as a completely randomized design with five herbicides and a control with three replicates for six months and the enzyme activities were measured at beginning of the experiment, and after three and six months. The concentration of herbicides was 0.27, 0.67, 0.67, 0.67, and 0.1 mg/kg soil for Haloxyfop-methyl, Metribuzin, Trifluoralin, 2, 4-D, and Tribenuron-methyl, respectively.

The results showed that the effect of herbicides on the enzyme activities was significantly different (p0.01). After 3 months, the herbicides decreased the urease activity in comparison to the control (34.9 µgN.g-1). The most reduction was related to Trifluoralin (24.8 µgN.g-1) which was 28.9% lower than the control. Urease activity increased after six months compared to three months, and this increase was 41.5% for Trifluoralin herbicides (35.1 µgN.g-1). Urease activity in control treatment in six months was not significant compared to the three months. All of the herbicides significantly reduced the dehydrogenase activity after three months compared to the control (0.6 µgTPF.g-1), so that the dehydrogenase activity was observed in Haloxyfop treatment with 0.01 µgTPF.g-1, which was 98% lower than the control. In all treatments, dehydrogenase activity after six months was significantly higher than that in the three months, so that the highest dehydrogenase activity was observed in 2,4-D treatment (1.44 µgTPF.g-1), which was significantly higher than the control.

The results show that the herbicides significantly decreased the activity of the enzymes compared to the control during the three months. After six months the enzyme activities recovered to the level before herbicides application. Probably this was due to a short lifetime of herbicide in the soil which was less than six months.

The use of chemical compounds is a very simple and effective way to protect agricultural products, against pests. Increasing the unplanned use of these pesticides is a concern, because the pesticides residue in fruits and vegetables can lead to very dangerous side effects in humans. Olive is one of the most useful and consuming fruits in the Iranian community that can be used as pickled olive. Therefore, in this study, fermentation ability to reduce residues of two commonly used pesticides, Malathion and Diazinon studied, and their changes due to product acidity, pH and salt content during the preparation and fermentation processes were meassured. The results showed that washing and debittering operations reduced Malathion and Diazinon to 73.59 and 93.38%, respectively. However, after 20 days fermentation, their reduction was 63.68% and 69.57%, and after 40 days, at the end of production, this decrease was approximately 90.5% and 97.98%, respectively. The residue of Malathion pesticide was significantly different in fermentation days; 1, 10 and 20 (P<0.05), while the mean value for Diazinon was not significant. Overall, the results showed that the fermentation process had a significant effect on Malathion residue (P<0.05) but did not affect Diazinon residue. Also, fermentation had a significant effect on the percentage of salt, pH and acidity (P<0.05). At the end of the fermentation process, no mould growing was observed, but the yeast grow was showed (CFU/g 1450), much lower than the number that could affect the quality of the product. Generally, the fermentation process effectively reduced the amount of residual pesticides, and the operations carried out in the production of pickled olives are more effective to reduce the amount of pesticide residues than the fermentation process itself.

Mold growth resistance of Polyurethane and Diotrol coatings containing natural (Thyme essential oil) and synthetic (IPBC) fungicides in both free and microencapsulated forms was studied. Polymethyl methacrylate (PMMA) microcapsules were prepared using solvent evaporation method by means of oil emulsion formation in water. Mold growth resistance against Aspergillus niger was determined by Filter Paper Disc method before and after aging process according to ASTM D 5590 Standard. Adhesion strength and surface roughness of coated samples were also measured. Results revealed that biocide-free coatings cannot provide adequate protection against mold growth, and addition of biocides, especially IPBC, significantly improved the mold growth resistance. Even after the aging process, microencapsulated biocides were able to provide better protection against mold growth due to controlled-release mechanism and shielding-effect of polymeric shell. Although the surface roughness of polyurethane coating was increased by using of biocides in both forms, especially microencapsulated ones, its adhesion strength reduced.

The intensive and inappropriate use of pesticides caused environment to be contaminated. Quantifying the fate of applied herbicides in the soil is essential for minimizing their mobility in the soil and environmental pollution. The leaching and degradation of the metribuzin herbicide in three soils were investigated under laboratory conditions. Metribuzin was mobile in the soils when tested using non-aged and aged soil columns. The mobility of herbicide in the soil is related to the adsorption phenomenon in the same soil. It was found that the mobility of metribuzin in the soils 7 and 5 (with less organic carbon) was more than the one in the soil 1. The difference in the adsorption affinity of metribuzin in different soils appears to be due to differences in soil properties, such as clay content, organic matter content and pH value. The calculated half-life values in sterile and non-sterile conditions ranged from 37.92 to 105.74 days. Metribuzin persistent in the soil was corresponded to columns 1, 5 and 7 respectively.