Year:2000 | Volume:6 | Issue:2|Papers Count:7

A preliminary field trail was conducted in Karaj area in 1998 to examine the efficacy of some chemicals in preventing fire blight blossom, infections on pear trees. The bactericidal effects of these chemicals plus streptomycin as a check were performed on KB medium using replica plating method. streptomycin (200 ppm) and starner (300 ppm) with 23 & 14mm inhibition zones showed respectively the most protective activities against E. amylovora.In field trail, 12 years old pear trees (cv. Duchesse d'Angouleme) with heavy natural infections were pruned before treating with four chemical compounds i.e. Bordeaux mixture (1%), starner (300 ppm), aliette (3 g/l) and copper oxychloride (3 g/l). The reperiment was conducted in complete randomized blocks design with 3 blocks and 2 replications per treatment in each block. The trees were sprayed 4 times at 6-7 day intervals at different bloom phenology i.e. bud swollen stage, 5%, 50% bloom and full bloom. Two weeks after treatments, the number of diseased blossoms (strikes) per tree in all treatments including non-treated check were counted. The disease incidence (number of infected strikes/tree) was significantly reduced in all treatments as compared to non-treated control. There was no significant difference among the treatments at 5% level by DMRT. Yet starner with %46.3 disease reduction ranked first among the other four applied chemicals.

In a ten years project, during 1990-1999, an Integrated Pest Management Program (IPM) was experienced on apple orchards in Mashhad (Khorassan) and Uroomieh (West-Azarbaidjan), which included both applid and natural biological control.It practically resulted, the exclusion of chemical isecticides and "lowered the level of economic damage to the range of 0.8% to 12.07%. In a classical biological program, aiming to reduce the population density of codling moth Carpocapsa pomonella (L.), in its different developmental stages such as: egg, larvae, adult at different yearly generations.The following two different approches were used:1- Direct classic of b1ocontrol, method, a sustained inundative release of Trichogramma and supplementary biotic agents were used.2- Indirect method we used: Pheromone-traps, repellents, and destoring overwintering full grown larvae by installing belt-traps on tree trunks.In monitoring population growth rate of other potential pests like European red-mite, Aphids, Leaf-mining moth.We provided support for their parasitoids and Predators by excluding Insecticides, protecting ground green-coverage.In any IPM in apple orchard, considering Biological control, and to maintain a logic mutual relationship between the pest population of their natural enemies and to support population of Trichogramma and other released biotic agentes, the following recommendation are made: exclusion of insecticide, timely farming practices sush as: regular irrigation, to maintain green coverage under the trees, land cultivation in fall, and also the use of winter oil spray and if necessary in spring and even during the summer-time.

In order to study the effect of different concentrations of Carbaryl and its time of applications on the thinning of "Golden Delicious" apple, factorial experiment with a R.C.B.D with 4 replications were carried out in 1998 in Maragheh district north - west of Iran. Factor A was two phases of spraying time at 10 and 20 days after full bloom and factor B was carbaryl concentration in 4 levels of 0 (check), 400 , 800 and 1200 p.p.m (active ingredient).Fruit density, flower abscission and flower transition to fruit percentage and some fruit quality, annual growth of trees were also examined. Resultes showed that: The time of carbaryl application (factor A) on average of fruits weight had significant differences comparing with check.The effect of carbaryl concentrations(factor B)on fruit abscission, fruit density, percentage of flower transition to fruit, fruit weight, the length and diameter of fruits was very significant.Interaction between A*B effect was very significant on total soluble solide of fruits. According to the results of this study, for chemical thinning of cultivar "Golden Delicious" apple in Maragheh region, application of 400 ppm active ingredient carbaryl 20 days after full bloom is recommended.  

The purpose of this study was to assess the feasibility of privatization of agricultural extension service in Iran, as perceived by extension specialists in Ministries Of Agriculture and Jahad Sazandegy and faculty members of agricultural extension.The sample was 160 extension specialists and faculty members. This consists of 40 extension specialists in Ministry of Agriculture, 40 extension specialists in Ministry Of Jahad Sazandegy and 40 faculty members of extension in several universities in Iran. The research design included a survey research, and a questionnaire was developed. The data was collected by interviewing sample population and was analyzed by using regression analysis and spearman ranking methods.The results of the study show that 51 respondents (42.5%) indicated that the public extension service was not successful in delivering goods and services to farmers. The three factors "weak linkages between research and extension, weak program planning, and problem of limited numbers of manpower", was found out to be the main reasons for inefficiency and ineffectiveness of extension service in Iran.The majority of respondents (62 respondents, 51.6%) stated that private sector can improve the current public system of extension in Iran, but they also indicated that private firms can not substitute for public extension.The results of the study show that majority of respondents (52.5%) disagreed with using only public resources for extension service in Iran.The perception of respondents was that the commodity - based and farmer - controlled approach can be the most usefull approaches for extension service in Iran. The majority of respondents stated that the mixed public and private entities can deliver goods and services effectively to the farmers.

In 1997 and 1998, the effect of inorganic, organic and integrated fertilizers systems on quantitive and qualitative traits of 4 sunflower cultivars were evaluated in Miandoab Agricultural Research Station, Iran. In both years, a split plot design in randomized complete block arrangement was used. The main plot was composed various levels of chemical fertilizers (40,80,120,160 and 200 kg N/ha), different levels of manure (6,12,18,24 and 30 t/h), a mixture of different rates of chemical fertilizers and manure, (N=40 kg+6 ton FYM, N=80kg+12 ton FYM, N=120kg+18 ton FYM and N=160kg+24 ton FYM/h) and control (no fertilizer) treatment, The four cultivars, Hysun-33 and As - 508 hybrids, and Armaverski and Record O.P.S., is made up of sub plot and randomized in fertilizer treatments. Grain and biological yield, seed number, 100 seed weight, height, oil percentage and yield were determined. The results obtained from the first and second years of the experiments showed that the different fertilizer treatments had significant effects on grain and biological yield, head weight, number of seed per head, seed 100 weight. Increase of application of N fertilizer and manure all characteristics recorded also increased, and highest grain and oil yield was obtained in both years of experiments in chemical fertilizer systems, with N=200kg/ha treatment and with organic fertilizer of 30 t/ha. The results of combined analysis of data from 1997 and 1998 years of experiment seed number, 100 seed weight, head weight, seed and oil yield, in integrated systems were significantly more than the chemical and orgaric fertilizer systems. The results showed that mixture of chemical fertilizer and manure improved efficiency use of chemical fertilizer and could decrease the use of chemical fertilizer in the cultivated land. The results obtained from the two years of the experimentals indicated that Hysun - 33 and As - 508 hybrid cultivars produced significantly high seed and oil yield than the other cultivars. But the oil percentage showed no difference between the cultivars. Biological yield and height of plant of two hybrid cultivars were lower than the Record and Armaverski cultivars and are therefore suitable for meachanical harvest and desirable cultivars for the Miandoab region.

One of the most important problems in economics is to investigate the relationships between variables. This can be done by applying different methods for analysis. The study of rice market in Iran shows that the price of different types of rice had fluctuation during last periods. In order words, during the time, both domestic and foreign rice prices have changed. Therefore, it is important to know how those fluctuation originate which may belong to specific variables, or perhaps affect other related variables. This can be chosen as a criteria by policy makers for policy making decision. This study uses the monthly data of different kinds of domestic and foreign rice prices (from Farvardin 1375 till the end of Esfand 1377) for 36 months. In order to, analyze the relationships between above variables, the causality test was used. The result show that, generally, the rice price variation originate from Thailand import price and then affects other import rices with one to two monthly lags, and lastly, causes changes in domestic rice prices. Therefore, according to the monthly data under study, it is known that the original cause stems from Thailand rices which affects other foreign rices and consequently continus to change domestic rice prices. The details has been described in the main paper.

In may 1997 a split plot experiment in a completely randomized design with twelve treatments and four replications were conducted in Ahwaz Agricultureal Research Station.Main plots were four irrigation levels consisting irrigation when soil moisture reached 70,60,50,40 percent of field capacity.Sub plots included three levels of potassium fertilizer 0,150,300 (Kg per ha-1) applied as potassium sulfate.Results showed that potassium ion has an important effect on leaf water potential and maintenance of turgor potential in water stress condition.Under severe water stress osmotic potential reached from -0.3 MPa in non application of potassium fertilizer condition to -1.7 MPa in 300kg ha-1 potassium fertilizer.Also, results showed that the potassium fertilizer strongly affected leaf rolling index and relative water content maintenance in water stress condition in sorghum plant. Potassium application (300 kg ha-1) increased leaf rolling index from 39% (with non - application potassium) to 47%.