نشریه پژوهش های کاربردی زراعی
پیاپی 86 (بهار 1389)

To evaluate the effects of foliar application of manganese and zinc on safflower under drought stress, experiments were conducted in 2001–2002 and 2002 –2003 crop years in a research field, 17 kilometers from west of Isfahan, Iran. The Experimental design was split factorial in randomized complete block with three replications. Four drought stress including, full irrigation, withholding irrigation at vegetative growth stage, withholding irrigation at flowering stage, and withholding irrigation at seed filling stage, were randomized to the main plot units and 12 treatments from combination levels of three cultivars including, Zarghan 279, Varamin 295 and LRV5151, and four foliar applications including, no foliar application, foliar application of water, foliar application of Zinc Sulfate (3000 ppm) and foliar application of manganese sulfate (3000 ppm) were randomized to the subplot units. After harvest, oil yield and percent of seed oil were measured and fatty acids composition of oil was determined by GC. Four species of fatty acids, stearic (2.0 %), palmitic (8.3 %), oleic (17.3 %) and linoleic (71.9 %), were consisted of about 99.5 % of total fatty acids of oil on the average and no linolenic acid was measured in treatments. Results indicated that oil percent and yield and percent of palmitic acid were affected by significant interaction of stress, cultivar and foliar application factors. Withholding irrigation at flowering stage and Zarghan 279 and LRV5151 cultivars caused to increase of oil percent when manganese used as foliar application. Withholding irrigation at seed filling stage increased oil percent and yield in Zarghan 279 and LRV5151 cultivars when zinc or manganese used as foliar application. In some interaction levels zinc and manganese foliar application significantly increased palmitic and oleic acids whereas these foliar applications decreased linoleic acid percent. As a whole, drought stress during flowering stage imposed the most damage to oil percent and yield and also decreased linoleic acid content and increased stearic and oleic acid content. So in case of oil percent and fatty acid composition in safflower, flowering stage is more sensitive to drought than vegetative or grain filling stages and foliar application of zinc and manganese can compensate the negative effects of drought on safflower plant.

Water stress is one the greatest limitation to crop expansion outside the present – day agricultural areas. Osmoregulation is one of the important factors, for plant drought tolerance. Many substances play important roles in plant osmoregulation for drought resistance, including proline, glycine, soluble sugars, trehalose, sucrose and K+ion, etc. In this context, a field experiment was conducted in Agricultural Research Center Jiroft and Kahnouj at 2005 and 2006 to investigate the effect of water deficit stress on proline accumulation and K+ ion alfalfa cultivars. The treatments were arranged in split – plots based on randomized compelte block design with three replications. The water stress treatment was main plot includy: severly stressed, moderately stressed and least stressed. Sub plots were included five alfalfa cultivars: Yazdi, Nikshahri, Rangar, Bami and Baghdadi. The results showed that with increasing water stress, proline accumulation was increased, but in severly stressed treatment proline accumulation was decreased. Proline accumulation rate was increased from 1.928 (µ moleg-1 leaf FW) in the state of least stressed treatment to a maximum of 2.291 (µ moleg-1 leaf FW) in the moderately stressed treatment. The highest concentration of K+ observed in severly stressed (2.258%) treatment. The highest concentration of K+ was occurred in the Bami Variety (3.71%). Proline accumulation rate was different among alfalfa cultivars. In the cultivars tolerant to drought (Nikshahri and Bami) with increasing of water stress, concentration of K+ increased more than sensitive one.

The relationship between carbon isotope discrimination (∆) and yield highly depends on the plant tissue analyzed, the environment and water regime. In this study the relationships between flag leaf carbon isotope discrimination (∆), grain yield, total and root dry matter, and harvest index (grain yield / total dry matter) were studied in eight durum wheat (Triricum durum L. var durum) landraces. Genotypes were grown in a glasshouse pot experiment under well-watered conditions based on completely randomized design with 3 replications. Results demonstrated that there were variations for Δ in the current germplasms. The mean Δ ranged from 18.83 to 20.08 ‰ among genotypes. All the measured traits correlated negatively with ∆, but the correlation coefficient was significantly only for grain yield. These results indicated that with selection of low Δ genotypes, genotypes with high grain yield could be selected indirectly in Iranian durum wheat landraces.

In order to study the growth pattern and seed yield of two different growing type of soybean in delay cropping in Karaj region, an experiment was conducted during the 2000-2001 growing season at the Agricultural Experimental Farm of Tehran University. The experimental design was a factorial with 3 replications in which the first factors were 3 different plant densities (20, 40 and 80 plant per 1 m2). Second factors were two different growing types of soybean cultivars (Hag: 3 type and Clark 63: 4 type). The sowing date in two cultivars was the same and it conducted in 21 May. Study the growth pattern showed that, the maximum total dry matter, leaf area index (LAI) and crop growth rate (CGR) achieved in 80p/m2 and than decreased with low density. The growth pattern in all treatment increased up to 85 day after planting and than deceased. The chances of leaf area index and crop growth rate were the same in two cultivars, already. In other hands the maximum relative growth rate (RGR) was observed in 20p/m2 in 40 day after planting. The results of seed yield showed that the effects of density on seed yield were different significantly in 1% levels. In this study the highest yields obtained in 80 p/m2 in hag and Clark as 66/4282 and 12/4464 respectively. The number of pods in plant decreased significantly when plant density increased. According to the results number of seed in pods unaffected significantly by density and cultivars. Weight of 1000 seeds was affected by plant density and cultivars. As by increasing the plant density, weight of 1000 seeds increased.

Genetic and environmental factors can affect the performance of the genotypes. Genotype ×environment interaction could be result different reaction of the genotypes in different environments. Therefore، determination of stability of the genotypes in different environments is the most important. In this study 15 winter and facultative bread wheat genotypes (including two check cultivars) were used. This experiment was conducted in 11 research stations in cold regions in 2003-04 and 2004-05 cropping seasons. Experiments design was randomized complete block (RBCD) with three replications. Based on results of combined analysis of variance، effect of year، location، genotype and genotype × year interaction effects were found non-significant. However، location ×year، genotype ×location and، genotype × location ×year interaction effects were significant. Based on stability parametric methods such as coefficient of variability (CVi%)، Shukla stability variance (σi2)، simultaneous selection for yield and stability (YS)، and non-parametric method of ranking genotype C-82-12 (Fdl4/Kauz) with average grain yield of 7035 kg ha-1،YS=18، R=5. 86، SDR=3. 427non-significant stability variance (σi2) and low environmental CV was identified as high yielding and stable genotype.

In order to evaluate seedling growth characteristics، of seeds produced under deficit irrigation and seed inoculation with rhizobacteria on soybean [Glycine max (L.) Merr] seed. An experiment was conducted based on split factorial in form of randomized completely block design with three replication. Treatments are include water stress [irrigation after 50 (normal irrigation)، 100 (mild stress)، 150 mm (severe stress) evaporation from pan of class A]، Cultivars [Manokin، Williams and SRF×T3 Line] and seed inoculation [Bradyrhizobium japonicum، Bradyrhizobium japonicum co-inoculated with Azotobacter chroococcum، control]. Bacteria factor was in main plot and placed cultivars and drought stress seeds condition in subplot. The result showed that water deficit had significant effect on seedling number، rate and length. Severe stress seeds condition had lower number and emergence rate compared to normal irrigation. Maximum seedling characteristics were for co inoculation treatment than no inoculation. Mild stress seeds inoculation with Bradyrhizobium japonicum had highest seedling length، dry weight and vigor was for normal and mild stress condition.

The aim of this research was to compare seven cultivars and three lines of rice (Oryza sativa L.) for competitiveness against barnyardgrass (Echinochloa crus-galli). A filed experiment was conducted in 2007 growing season in Mazandaran province، North of Iran. In this experiment، seven rice cultivars (Khazar، Sepidrood، Nemat، Dorfak، Fajr، Shiroodi، and Dailamani) and three lines (Line 830، Line 841 and Line 843) were sown with and without barnyardgrass. Layout of the experiment was a factorial design with four randomized complete blocks. Each cultivar or line was planted at its own optimum density، while density of barnyardgrass was 20 plants per square meter. Results showed that in all rice cultivars and lines tested، yield and its components were significantly reduced in the presence of barnyardgrass. Moreover، there was a significant difference among rice cultivars and lines in competitive index (CI) and ability withstand competition (AWC). Line 843 had minimum yield reduction percentage (18%)، highest CI (2. 43) and AWC (82)، while Khazar cultivar had maximum yield reduction percentage (50. 65%)، lowest CI (0. 32) and AWC (49. 5%). Correlation analysis confirmed that there was a positive significant correlation among rice yield، CI and AWC. The Cluster Analysis showed that all cultivars and lines fell into four different clusters. First، khazar cultivar had high yield potential under weed-free conditions، but low CI and AWC. Second، line 843 had high yield potential under weed-free conditions، CI and AWC. Third، shiroodi cultivar had high yield potential under weed-free conditions، and low CI but high AWC and forth other lines and cultivars had low CI and AWC. Based on this experiment، line 843 was the most competitive Line and khazar cultivar was the least competitive cultivar against barnyardgrass.

In order to study the effect of phosphate solubilization microorganisms (PSM) and plant growth promoting rhizobacteria (PGPR) on yield and yield components of corn (Zea mays L.) cv. SC604 an experiment was conducted at research farm of Agriculture College located at Sari، Iran during 2007. Experiment laid out as split plot based on randomized complete block design with three replications. Three levels of manures (consisted of 20 Mg. ha-1 farmyard manure، 15 Mg. ha-1 green manure and check or without any manures) as main plots and eight levels of biofertilizers (consisted of 1-NPK or conventional fertilizer application; 2-NPK+PSM+PGPR; 3-NP50%K+PSM+PGPR; 4-N50%PK+PSM+PGPR; 5-N50%P50%K+PSM+ PGPR; 6-PK+PGPR; 7-NK+PSM and 8-PSM+PGPR) as sub plots were treatments. Results showed that farmyard manure application increased row number، ear weight، grain number per ear، grain yield، biological yield and harvest index compared to check. Furthermore، using of PSM and PGPR in addition to conventional fertilizer applications (NPK) could improve ear weight، row number and grain number per row and ultimately increased grain yield in green manure and check plots. According to results in all fertilizer treatments application of PSM and PGPR together could reduce P application by 50% without any significant reduction of grain yield. However، this treatment could not compensate 50% reduction of N application.

There are several methods to increase the amount of agricultural production، but the scarcity of resources leads to special considaration of factors productivity promotin for the production augmentation. Rice is one of the most important crops which our country is facing with shortage of it. This study by estimating the production function investigates the productivity and allocative efficiency of inputs in rice farms of Guilan province. To this end، the required data was collected from 280 farmers and the production function was estimated by Eviews software. The results indicated that the cultivated area، water، labor and fertilizer have significant effects on the producing process، but the mentioned factors are used uneconomic. Although the magnitude of partial and total productivity are different in the counties of the province، but in general، Astaneh and Talesh، are in better situation compare with whole the province.

Thyme (Thymus vulgaris L.) is an important medicinal plant in perfume and medicine industry. In this research، we assessed effects of salinity stress on morphologic، physiologic، and chemical characteristics of (Thymus vulgaris L.). In this research we used complete randomized blocks with 6 treatments and 4 replications. Irrigational levels of water salinity levels were (0، 60، 90، 120، 150 mMolL-1) sodium Chloride The results showed that salinity stress had significant effects on growth parameters، prolin content and thymol percent. With increasing irrigational levels of water salinity، plant height، number stem side، dry weight of plant، thymol percent decreased and root mass، dry weights of root، length and prolin concentration increased. Highest levels of topsoil parts of plant، root and prolin content were produced consequently without salinity stress، high salinity stress (120 mMolL-1) and very high salinity stress (150mMolL-1). Highest levels thymol percent in control and with increase salinity decreased.