Year:2000 | Volume:6 | Issue:1|Papers Count:9

The fungicide Edifenphos and Propicnazole have vast use in paddy rice field in northern Iran. The unicellular algae Selenastrum capricornutum and zooplankton Daphnia magna, as test organisms in fresh water were examined for ecotoxicological studies, The toxic effects of forementioned toxicants from bioassays were evaluated.S.capricornutum in pure culture medium are exposed to increasing concentration of the two toxic chemicals for determining the acute toxicity. From 6 days experiments, the growth assessed based on measuring turbidity. During reduction of growh at 50% in control, EC50 for Edifenphos and Propiconazole were measured 1040 µg/l and 1856 µg/l respectively. Concerning D.magna it was 1.5 µg/l and 9µg/l respectively. The impact of above toxicants with concentration of 1/4 EC50, 1/2 EC50, 3/4 EC50 and EC50 were chosen for test feeding study of D. magna with Scenedesmus obliquus in a period of 5 hours. The EC50 value by Edifenphos influenced on filtration and ingestion rates calculated 527µg/l and 608µg/l respectively. This occured by Propiconazole 3853 µg/l and 4837µg/l respectively. The Results of these investigations cleared that Edifenphos and Propiconazole are highly toxic for S.capricornutum and D.magna. S.capricornutum are more vulnerable than D.magna. Toxicity of Edifenphos on these two test organisms proved more hazardous than Propicnazole.  

Successful in vitro shoot proliferation and elongation of mulberry winter buds (Atsubamidori) was carried out. Vegetative winter buds obtained from field trees were surface sterilized and incubated on MS (1962) nutrient medium supplemented with different concentrations of agar (4, 6 and 8 gr/l), BA (0, 0.5,1,1.5,2.0, and 2.5 mg/l) and carbohydrates type (sucrose and fructose 30 gr/l).The pII was adjusted to 5.6±0.1 with KOH before sterilization. All cultures were maintained in an air condition room at 28˚C with 16 hr light (4000 LUX) and 8hr darkness.The result of this research indicated that the best condition for shoot proliferation and elongation was MS medium supplemented With 6 gr/l agar %3 fructose and 1mg/l BA.

The migratory locust, Locusta migratoria L. 1758 is widely distributed throughout Africa, Europe, Asia, Australia. It is a major pest in sugarcane fields in Khuzestan province. This research was carried out during 1998-1999 on crowding effects on morphometeric, biologic characteristics and also color on migratory locust under laboratory conditions.The male and female collected from sugarcane fields and hatchlings were obtained from eggs that had been laid by females to named Ft. Hoppers were subjected to six different densities (1, 3, 6, 15, 50, 100 per cage). Crowding effects were found in F/C, H/C ratios, hopper coloration, adult longevity, number of egg pod per female, number of eggs per pod and percentage of activity per adult. This research was continued until F2 generation and showed that crowding effects appeared low and late in population of Locuta migratoria in Khuzestan province.

Self - sufficiency in production of essential agricultural products has been one of the most important goals of the government after the victory of the Islamic revolution. So different policies has been implemented for this purpose. In this paper we studied the relationship between dominant economic agricultural variables such as: value-added, price, export and investment with fiscal and monetary policies using Vector Autoregression and Cointegration techniques for the time period 1350-1376.Results show that:- Fiscal and monetary policies have negative effect on agricultural investment. - Fiscal and monetary policies have positive effect on agricultural value -added and the effect of fiscal policy is greater than monetary policy.- Fiscal and monetary policies have positive effect on agricultural export and negative effect on the ratio of agricultural export to total non-oil export.- Fiscal and monetary policies have positive effect on agricultural prices.- In short-run monetary policies are more effective than fiscal policies but in longrun fiscal policies are more effective on agricultural variables.

Shortage of onion in market occurs during some winter months. Effects of N fertilizer and planting density in out season production of onion was studied in Dezfoul Agricultural College in 1998-1999. Design of the experiment was split plot and replicated 3 times. Main plots were consisted of 4 levels of N fertilizer (150, 175, 200, 225 kg N ha-1) and subplots were allocated to 4 levels of planting density (40, 55, 70 and 85 plants m-2). Results showed that nitrogen affected bulb diameter and bulbing index which highest values obtained when 200 kg N ha-1 applied. Planting density had a negative linear correlation with diameter and weight of bulbs and no real bulb was formed in highest density. The affect of N on total plant weight and number of bolted plants were not siginificant, howere, total bulb yield and average bulb yield weight were affected by N where highest values obtained when 225 kg N ha-1 applied. Total yield affected positively and increased linearly as planting density increased, but there was a negative relationhip between plant weight and bulb weight with plant density, as the maximum weight of them occurred in low plant density. both of nitrogen and plant density levels had no any effects on plants bolting.The resuls of this experiment indicated that out season production of both onion bulb and scallion in Dezfoul region is possible. Application of 200 kg N ha-1 with density of 40 plants m-2 for bulb production and 150 kg N ha-1 with 85 plants m-2 for scallion production is recommended.

Effect of colour and design of the trap, dosage of pheromone component in rubber capsule and trap height on the efficiency of Codling moth pheromone traps were evaluted. The study was conducted in Fars province. A Complete Randonized Block Design (CRBD) used with three blocks and four replications in each block.To find the best trap color, yellow, green, brown and white colors were tested. Using Duncan procedure, yellow and green colors were significantly different from each other at the P=1%. Green, white, brown were ranked in a separate group and yellow, brown and white were ranked in another group and were not significantly different at P=1%. The majority of Codling moths were caught in yellow trap.To determine the best suitable trap design, Three different pheronone traps, Zoecon, Delta and Cylinderical were tested. Zecon traps with highest moth catches were superior in comparison with other trap designs. Three different heights, one meter from the ground, middle of the canopy of the tree and top of tree were tested in order to determine the role of the trap height on the efficiency of traps. The highest numbers of moths were caught in the traps which were positioned on the top of the tress.The doses of 0.5, 1, 1.5 and 2mg doses of the pheromones formulated in Plant Pest and Diseases Research Institute (PPDRI) compared with a foreign standard rubber capsule (1mg, Agrisense, England). The results of the test revealed that the foreign standard rubber capsule was superior and had more catches at P=1%. The different PPDRI formulations were not significantly different from each other at P=1%.

Experiments was conducted in 1996 in which the effect of two planting pattern (row width) (55 and 70 cm) as sub- factors and four planting densities (3.0, 4.5, 6.0, and 7.5 plants per squares meter) as sub-sub - factors on tuber morphological characters and analysis of tuber yield in three potato varieties (Draga, Aoula, and Kasmoos) as main-factors was studied. In this experiment, the combination of three factors carrying out in statistical spilt-split plot design in randomized complete block design model and four replications. Number of tubers increased with reduction of row width. However, row width had little effect on tuber mean weight, tuber dry weight, tuber yield and harvest index. These results suggested that the usage of wider rows which is currently used in practice in limited areas, should be considered, especially where planting and harvesting practice facilities is target.Increasing planting density caused an increase in tuber number, tuber dry weight, tuber yield and harvest index, but the response to the final increments of planting density was small. Tuber mean weight in Draga Cv. and Kasmoos Cv. were greater than Aoula Cv. due to larger numbers of tubers produced by Aoula Cv. Finaly, kasmoos Cv. with row width of 70 cm and planting density of 6.0 plants per squares meter was the best and suggestable treatment combination for Ardabil region which have been capable to obtained the maximum tuber yield.