Year:2001 | Volume:7 | Issue:2|Papers Count:8

In the recent years the spread of Dutch Elm Disease in, Iran has extended from northen to the southern Alborz Forests. Many ornamental plants in parks and other greens in different cities, especialy in Tehran are infected by the disease.In our study, in 1996 to 1999, we aimed at achieving an Integrated Pest (IPM) Management program in controling & containing the Dutch Elm disease. It was recognized that focus should be made to the biocenotic aspects of the pathogenic fungus (Ophiostoma ulmi (Buisman)), determination of its interspecific relation with the host trees (Ulmaceae) & vector insects, especially Scolytus multistriatus. In this regard, the following studies have been taken: -Biological characteristic of O.ulmi, its pathogenesis and regional distribution.-Host characteristic of elm trees toward the pathogenic fungus and the host-dependency of the fungus in developing the disease under field or glasshouse conditions.- Faunestic features of vector beetles (Scolytidae), their coexistence with the pathogen and their biological control along with identification of natural enemies of Scolytidae species and evaluation of thier role upon reduction in chemical control.- Injection of Pseudomonas fluorescence along with chemical fungicids (Benzimidazol group) for direct controlling of O.ulmi.- Indirect prevention of the disease through integrated pest management and through methods such as; improving tree vigor; managing natural enemies of insect vectors, Scolytus spp. and other pests by reducing common chemical control programmers in parks and other greens in urban saera-On time sanitary measures on the elm trees which strengthen the planned IPM strategy in preventing and controlling the Dutch Elm Disease.

The shortage of woody raw materials, derives the future development of national cellulosic industries on using non-wood lignocelluloses material such as bagasse. Therefore, the choice of relevant technology for the later has to he based on a logical and comprehensive model.To that end, criteria for future cellulose industry were developed and thier velatine weight were determined having three options and 17 criteria, decision making matrix was constructed and required inputs were developed during the study. In the next step, based on the quantitative and qualitative criteria, the three option were prioritized. The results reveal they the TOPSIS Model in a stage wised state indicated that the printing paper industry, M.D.F. and particleboard industries are respectively the first, second and the third priorities.

Seed germination is the begining of life cycle for many crops. Snitable methods of seed selection and production have great effects on the yield. In this study, a field work was preceded hy a laboratory experiment in order to evaluate the seed vigour in seven sorghum lines. The field experiment was a RCBD with three replications and was carried out in 1998, Karaj, Iran. Each experimental plot was 2.6x7m with four rows (65 cm between the rows). After seedling emergence, the germination percentage was recorded. When the seedlings were at 4-6 leaves thinning was done to reduce the space between them to 6cm in a row and other necessary practices were carried out on time until the seeds were fully matured. Samples were taken from all the seven sorghum lines and in the laboratory, using RCBD design, standard Germination Test (G), Cold Test (CT), Accelerated Ageing Test (AA), Electrical Conductivity Test (EC) with four replications were implemented on the samples. The results indicated that the sorghum lines KFS1, KFS2 and KFS4 are significantly different in seed vigours, percentage of field emergence and also the fresh and dry matter yields of forage.

To determine the contribution of different components of grain yield, 9 varieties of barley including; 5 varieties of six rowed and 4 varieties of two rowed were studied in research fields of the University of Cukurova in Turkey. The objectives of the study were to dentify the most effective components and the influence of each one of them in grain yield for eventual use in Breeding programs.The experiment was carried out under a completely randomize block design with 4 replications. Multiple regressions between the grain yield, 1000-grain weight, plant height and seed weight in ear as the dependent variable and all other characters as independent variable were carried out.In multiple regression method, 12 characters were identified contributing a total of 81.8% grain yield variance. Characters like harvest index and 1000-grain weight together shared 65.1% grain yield variance and the former alone contributed 72.7% to the figure. The 1000-grain weight was considered as the dependent character & all the 12 characters together contributed 93.1% of the variance in 1000-grain weight. Characters like grain yield and flag leaf area which had a close correlation with 1000-grain weight, contributed 85.5% of the variance in 1000-grain weight. 12 independent characters explained 80% of the variance in harvest index and characters like grain yield, seed weight and seed, number per ear and hectoliter weight had a strong correlation with harvest index and showed 54.7% of the variance. All the independent characters explained 86.4% and 91.2% of the variance in plant height and the number of seeds per ear respectively. In this study the most important yield components is 1000-grainweight and the next is harvest index.Based on our observation on the tested varieties, the characters like seed weight per ear, flag leaf area index, 1000-grain weight and harvest index have the strongest correlation with yield and therefore they are recommended as a selection criteria for breeding programs of grain yield.

Nitrogen-fixing bacteria have an important role in soil fertility. They are used as biofertilizer for agricultural plants. Different types of unrelated gram positive and negative families are categorized in three basic fixer groups: symbionts, free-livings and associative.To determine the accuracy and activity of these bacteria in some Gilan wetland soils, 40 roots and rhizospheric rice soil samples were collected from 5 rice fields. Isolation and genus identification were performed by selective media, micro Scopic examination and biochemical tests. Nitrogen fixation was assayed by acetylene reduction test. All isolates were associative nitrogen fixer and belonged to Entrobacteriaceae, Pseudomonas and Bacillus genera. The isolates of genus Pseudomonas were dominant and the others (Serratia, Introbacter) were smaller in numbers.Acetylene reduction assay results showed that the nitrogen fixation ability of isolates is weak.

Fast computers and powerful data management & graphk software's are indispensable elements of precision farming technology. Activities like yield monitoring and on the go soil sampling provide vast amount of data on the variation in crop and soil conditions throughout the field. The collected data must be processed and reduced into maps to provide serviceable information. The objectives of this study were to develop a software for analyzing the compaction data of a soil excavator and convert it into a colored map. A program was written in C++ language with about 2000 lines and it was evaluated by a simulation method. For testing the software, a force measuring hydro-electronic transducer was designed and fabrkated. By exciting the transducer its output signals were sent to the software which was loaded on a Pentium Pc. Execution of each part of the program follows a flow chart which starts by an icon identifier on the main display. On line progress of the compaction map was visible during the operation period of the transducer. After conduction of each test and making the selevant file, tables of data and functional plot of compaction versus depth at any soil profile is accessible. Results showed that with high confidence, this software could be conjugated on soil compaction scanning. Its facilities seem to be valuable enough to make it as a geographical information system (GIS) software.

Trissolcus esmailii sp. n. is described from Darab and Tooysserkan; Iran. A key to the world nearest species of Trissolcus is provided.