نشریه یافته های نوین کشاورزی
سال پنجم شماره 1 (پیاپی 17، پاییز 1389)

In order to study effect of there plant densities on phonological traits of 5 exotic sweet and super sweet corn varieties، this experiment was carried out in a factorial design based on RCBD with 3 replications. Experiment was done at research field of Seed and Plant Improvement Institute at Karaj during 2008. Results showed that، effect of various plant densities have non-significant on days to tassel formation، pollination and ASI، but the studied densities showed some effect on days to silk development، with respect to the experiment results، the increase of plant density from 75000 to 95000 plant/ha، caused the days to silk development to increase too، and varieties which needed more days to silk development، were also late maturing varieties. There was significant difference between the studied values regarding the days to tassel formation، the days to pollination، and the days to silk development which was absent with respect to ASI. The Obsession variety showed the highest number of days to tassel formation، pollention and silk which indicates its late maturing in comparison to other studied varieties.

Some plant species are tolerant to environmental adverse conditions so that with their functional mechanisms prevent more production of free radicals of oxygen or counter with produced free radicals of oxygen. This study was done to investigate the effect of lead and copper on Lathyrus sativus in contaminated soils with these elements. To evaluate and recognize the study species ability against heavy metals lead and copper an experiment was carried out on Lathyrus sativus cultivar Zanjan in 2009. The experiment was carried out factorially as randomized complete design with four levels of lead Pb (NO3) 2 (0، 200، 400 and 800 mg/kg) and four levels of copper Cu (So4) 2 (0، 150، 300، 450 mg/kg) were used. Although the results suggested the decrease in total chlorophyll content and lipid membrane under the toxicity of lead and copper، the more activity of the enzyme Superoxide dismutase (SOD) along with the increase in the levels of lead and copper in thid species prevented the more production of free radicals of oxygen in the study species، so that a negative coloration was observed between chlorophyll a، b and total chlorophyll and the enzyme superoxide dismutase (SOD). Also the coloration between Malondialdehyde (MDA) which is a means for measuring the lipid per oxidation process، and the enzyme Superoxide dismutase (SOD) was positive that means the increase in this biomarker content which is a sign of more production of oxygen for lipid membrane destruction، was accomplished with the more activity of enzyme Superoxide dismutase (SOD) for more digestion and elimination of destructive oxygen. Also the water condition in leaf tissues (RWC) was not effective by these elements.

In order to investigate the effect of biological fertilizers on yield and yield components of bean، a field study was conducted during spring and summer 2010 in research farm of college of Arak Islamic Azad University. The factorial experimental of the study comprised of RCBD with three replications. Three varieties of bean were Goli (indeterminate)، Sayad (Semi determinate) and Derakhshan (determinate). Mycorrhiza fungi including no inoculation and Glomus intraradices and three levels of Rhizobium phaseoli were including: no application strain Rb116 and strain Rb133. interaction between mycorrhiza، rhizobial and cultivars on yield and yield components showed highest grain yield and biological yield، respectively، with the 2664 kg/ha and 6333 kg/ha of the treatments inoculated with mycorrhiza (Glomus intarardices and rhizobial strains Rb131 and goli variete was obtained. The lowest yield of the treatments used mycorrhiza fungi and rhizobial bacteria zero levels، with 1172 kg/ha and Derakhshan variete was obtained.

Arak County with an area of 5594 km2 is located in Markazi province. The altitude ranges from 1650 m in the Meighan lake to 3118 m in Sefidkhani mountain. The mean annual precipitation varies from 200 mm in Ebrahimabad plain to 440 mm in the Sefidkhani mountains. Thus، this area has climatic variation and floristic richness. This study was conducted to introduce، classify and determine the distribution of medicinal plant species of Arak county. According to field studies and literature review، medicinal species was listed and some information including scientific name، family name، Persian name، botany specifications، distribution area، habitat altitude from sea level، utilized organ were recorded for each medicinal plant. According to results، in Arak county 143 medicinal plants species were identified belonging to 121 genera and 40 families. Asteraceae with 17، Papilionaceae with 16، Lamiaceae with 14، Brassicaceae and Linaceae (each with 9)، Rosaceae with 8 and Apiaceae with 7 species، were the most families that have the highest number of medicinal species. About 40 percent of medicinal plants grow in the plains and 60 percent grow in mountainous areas. 126 species of medicinal plants were self-grown (wild) in natural resource boards and 17 species were planted. Considering the diverse climatic and topographic conditions and diversity of medicinal species in Arak county، this area has a high potential for development of medicinal plants cultivation.

This experiment was conducted to examine the effects of drought stress on the morphologic characterizes and yield of Hull- less barley. This research was conducted as CRD with 6 replications and 4 levels of drought stress in green house. Drought levels were check (D1) with -0. 3 MP، low stress (D2) with -0. 6 MP، medium drought (D3) with -0. 9 MP and sever drought (D4) with -1. 2 MP. Results indicated that drought stress significantly influenced on main stem length، ear length، plant high، percent of unfertile tillers، percent of fertile tillers، grain number in main ear، weight of 1000 grains and yield. Pod yields of -0. 3 MP، -0. 6 MP، -0. 9 MP and -1. 2 MP were respectively about 55، 46، 42 and 33 g per pod. While drought stress had no significantly effect on number of total tillers، main stem dry weight، tillers dry weight and leaf dry weight.

In order to determine، genetic variation for quantitative and morphological traits related to grain yield in ninety nine pure lines of barley derived from barley breeding programs in different field stations and one commercial cultivar (Nosrat) as check. This study was conducted using an alpha-lattice design with two replications at the Seed and Plant Improvement Institute (SPII)، Karaj in 2007 - 2008 cropping season. The number of days to physiological maturity showed the highest (h2=100) and the grain yield (h2=60. 5) medium heritability، respectively. Genetic correlations between the traits were similar to phenotypic correlations and were commonly greater. Factor analysis for studied traits revealed three factors which justified 100 percent of the total variation. The first factor which was named yield factor was included number of grain per square meter، grain yield and grain filling rate. The second factor consisted number of spike per square meter، number of grain per spike and grain weight per spike. The third factor included grain filling rate، thousand grain weight، and spike length. Path analysis also detected the same results as the other analyses and indicated the importance of number of grain per square meter in increasing grain yield. Cluster analysis based on all traits، detected three groups and identified the lines that derived from a specific breeding program/location were not very different and distributed in all three groups.

In order to study of regression coeficient for irrigation periods and traits of castor plants this fiels experiment was done in 2010 at Damghan Islamic Azad University research farms. The experiment model was randomized complete block design with three replications. Irrigation periods intervals were every 5، 10 and 15 days. Plant densities were 5 plants per square meter. After data harvesting we used from SAS statistical software and mean comparition was calculate by Duncan''s multiple range test at 5%. the correlation coeficient between plant characteristics irrigation periods were stimated too. All traits studied showed significant differences for the period of irrigation and the highest yield and lowest yield in a period of 5 days of irrigation in the irrigation period was 15 days I attribute 15 percent oil and protein content in irrigation water during the 10 days had the highest. Attributes associated with the irrigation effect was linear (r =0/95**) and the correlation with oil yield significant and negative r=0. 65*، % protein and significant and negative relationship was -0. 85**Percent of the oil with the water cycle has a positive slope of the line that represents.

To study the effect of plant density، irrigation periods and nitrogen application on growth indices of foliage sorghum (Sourghum bicolor var. Peghah) an experiment was conducted as split، split plot based on RCBD with 4 replications at Hamadan، Iran in 2007 growing season. plant density 100، 200 and 400 thousand plants per hectare (D1، D2 and D3)، two levels for irrigation period in every 10 and 15 days (I1and I2) and two levels of nitrogen application 100،200،100 and 100،100،200 Kg Urea/ha at sowing date، 45 and 65 days after sowing date stages respectively (N1 and N2)، were investigated. The results showed that the maximum total of dry foliage yield up to 18. 44 t/ha was obtain by D1I1N2 treatments. Furthermore، the CGR trend for the lowest plant density (10 plant/m2) in all plant growth stages were upper than other plant density crop growth rate index. In this study، relative growth rate (RGR) trend by enhance the plant density were reduce until 1100 GDD adsorption and net assimilation rate (NAR) at 800 GDD were changed from 0. 03 to 0. 18 g/g/m2/GDD.

In order to study of temperature treatment on yield and yield component of rice (Tarom mahale and Fajr varieties) a green house experiment was carried out in deputy of rice research institute of Iran (Amol) in 2009. The experiment performed in the form of factorial split plot based on CRD with three replications. The stages of the varieties (Tarom mahale and Fajr) were selected as main factors and the stages of temperature (16 and 32 C°) as well as four growth stages (the average of grassing till the appearance of green cluster، stalking، pregnancy، blooming and grain becoming full) were considered as sub-factors. Results showed that the varity of Fajr، because of having more numbers of effective tiller، the number of spike in hill، the length of spike، the number of whole grain head in cluster and the number of full grain head in cluster، had the most of grain yield (23. 37g/hill)، in comparison with the variety of Tarom mahle (19. 72 g/hill). Grain yield in temperature of 32 C°، because of having the higher (23. 6 gm/hill)، in comparison the temperature of 16 C° (19. 5gm/hill) and when decreasing temperature from 32 C° to 16 C° a decrease of 21% for grain yield obtioned. The stage of grain becoming full، because of having more number of spike in hill، the length of spike، the number of whole grain head in cluster and the number of full-grain head in cluster had the most of grain yield (24. 58 g/hill) and from growth level of grassing till the appearance of green cluster because of having less number of cluster in hill and 1000 grain weight had the least amount of yield (19. 01 g/hill).