a.h. shiranirad

Investigating the role of agronomic factors is very important in improving the quantitative and qualitative characteristics of oilseeds. In order to determine the composition of fatty acids and grain yield in camelina (Camelina sativa L.), a two-year experiment (2017-19) was conducted in Karaj, Iran. The experiment was carried out as a split plot-factorial in a randomized complete block design with three replications, where the planting date (7th Oct., 22nd Oct., and 6th Nov.) in main plots and planting density (40, 50 and 60 plants m-2) and humic acid (including non-application and application of 0.003 HUMAX 95-WSG) in two stages of 4-leaves and stem elongation were considered in sub-plots. The highest grain yield with an average of 2485 kg ha-1 was obtained on 7th Oct., at 40 plants m-2 and application of humic acid. In addition, application of humic acid in delayed planting date (6th Nov.) and 40 plants m-2 showed the highest positive effect on 1000-grain weight and grain yield (wit increases of 17.8 and 32.7%, respectively) compared to non-application. Also, application of humic acid in delayed planting date (6th Nov.) and 40 plants m-2 showed the highest percentage increase of oleic acid (0.9%) compared to non-application. Furthermore, application of humic acid in all normal (7th Oct.), relatively late (22nd Oct.) and late (6th Nov.) planting dates, caused a significant decrease of erucic acid and glucosinolate concentrations compared to non-application. Therefore, application of humic acid is beneficial to camelina growth and grain yield, particularly when sown in a delayed date.

The new oilseed rape cultivar Nilofar (R15), is the result of screening and purifying single plants in segregating generations derived from the cross "Symbol×Orient". During five years of consecutive cultivation, screening of single plants was continued to access pure lines using pedigree method and pure lines were selected in F4 generation. During cropping season 2008-2009, 84 pure lines were evaluated in preliminary yield trial. Results showed that Nilofar variety with a mean yield of 3352 kgha-1 had higher grain yield by 45% compared to the Okapi control variety with a mean grain yield of 1833 kgha-1. In the Value for Cultivation and Use (VCU) trial in six research stations of cold and mid cold regions of Iran including Karaj, Isfahan, Hamedan, Islam abad-e- gharb, Khoy and Arak during two cropping seasons 2009-2011, Nilofar variety with an average grain yield of 3783 kgha-1, ranked first and had 16.1% grain yield more than the Okapi. Under delayed sowing date and stopping irrigation from silique development stage in Karaj during two cropping seasons 2012-2014, Nilofar with 1986 kgha-1 and 0.62 kgm-3 in term of grain yield and water use efficiency, respectively, was superior to Okapi with 1626 kgha-1 grain yield and 0.62 kgm-3 water use efficiency. The glucosinolate content of Nilofar variety was less than 10 μmolg-1 of dry matter and the erucic acid content of the oil was less than 2%. The results of the extension research project in Kermanshah province showed that the mean grain yield of the Nilofer variety at two sites of Sarab Nilofer and Mahidasht was 4004 kgha-1, which was 14.8% higher than the Okapi control cultivar. Due to its high grain yield potential and appropriate agronomic characteristics, line R15 was released under the name of Nilofar and is recommended for cultivation in the cold and mild cold regions of Iran.

In order to investigate the effect of salicylic acid application on reducing the effects of cold stress due to delayed planting in rapeseed genotypes, this experiment was conducted as a factorial-split plot during the 2014 and 2015 growing seasons in the Faculty of Agriculture, University of Zanjan, Iran. Interaction of the sowing date (11th September and 7th October) and salicylic acid (control (spray with distilled water), 250 µM and 500 µM) were as the main-plot and rapeseed genotypes (Karaj-3, L14, Okapi, Zarfam) were assigned to subplots. The effect of planting date* salicylic acid* genotype on winter survival percentage, grain yield and its components, harvest index, and biomass was significant. Delayed planting reduced survival percentage of all rapeseed genotypes; but the severity of reduction varied depending on the genotype. It was also found that the decrease in survival percentage due to delay in planting can be partially compensated for by the use of salicylic acid, which varied depending on the salicylic acid concentration and genotype. Delayed planting date reduced grain yield in all genotypes and salicylic acid application had the opposite effect and increased grain yield. Karaj-3 had the highest grain yield on 7th October planting date and 500 µM salicylic acid, while Zarfam had the lowest grain yield on 11 September and 0 µM salicylic acid. Application of salicylic acid compensated for part of the reduction in yield due to delay in planting, so that the lack of application of salicylic acid and the use of 250 and 500 μM salicylic acid in planting on 7 October caused grain yield reduction in Karaj-3 genotype by 36, 31 and 18% respectively, compared to 11 September, while grain yield in L14 genotype showed 26, 21 and 8% reduction respectively, compared to 11 September planting date. The grain yield of Zarfam genotype at delayed planting date decreased by 9% and 5% and increased by 13%, respectively, in conditions of non-application and application of 250 and 500 μM salicylic acid compared to the 11 September planting date. There was a positive significant correlation between grain yield components and winter survival percentage. Although delayed planting reduced grain yield, yeld components, harvest index, and biomass in all genotypes, the severity of the decrease varied among the genotypes. Consumption of salicylic acid moderated the effect of delay in planting and this modulatory effect was higher in the application of salicylic acid with a concentration of 500 μM than 250 μM. In general, the results showed that in both planting dates, the Karaj-3 genotype had the highest grain yield in all salicylic acid levels, so it is recommended for planting in areas with similar conditions.

Nafis variety (line L72), suitable for cultivation in the cold and moderately cold regions of Iran, is the result of the selection and purification in segregating generations derived from the cross Orient×Modena. Selection of single plants was carried out during five consecutive years using pedigree method until accessing pure lines and then pure lines were screened in F6 generation. Pure lines along with Okapi as check cultivar were evaluated in the preliminary yield trial in experimental farm of Seed and Plant Improvement Institute in 2009. The result showed that mean seed yield of L72 with 3650 kgha-1 was 30.7% higher than Okapi. The study of adaptability of selected lines in Karaj, Hamedan, Zarghan and Kermanshah during 2012-2013 and 2013-2014 showed that line L72 with seed yield of 4137 kgha-1 had the highest grain yield among studies genotypes where its seed yield was 6.7% higher than Okapi and had a good yield stability based on environmental variance statistic. Results of complementary trials for line L72 in Karaj, Hamedan, Zarghan, Isfahan, Khoy and Kermanshah during 2014-2015 and 2015-2016 indicated that this line with grain yield of 4336 kgha-1 had higher yield compared to other genotypes. Field disease assessments indicated high tolerance of L72 to sclerotinia compared to check cultivar Okapi. Results of on-farm trials in farmers' field of Kermanshah province showed that line L72 had 13.7% higher grain yield compared to Ahmadi as check cultivar. Results of on-farm trials in farmers' field of Isfahan province under normal irrigation and irrigation cutting from pod setting stage showed that line L72 had 1.2 and 9.1% higher seed yield than Okapi as check cultivar, respectively. Therefore, due to desirable characteristics of line L72 such as higher seed yield and yield stability and relative tolerance to sclerotinia stem rot compared to Okapi as check cultivar, this line was released as Nafis and is recommended for cultivation in the cold and moderately cold regions of the country.

To investigate the effect of delayed sowing on seed and oil yields of rapeseed (Brassica napus L.) genotypes, a field experiment was carried out at the research field station of Seed and Plant Improvement Institute, Karaj, Iran in 2015-2016 and 2016-2017 cropping seasons. The experimental design was split plot arrangements in randomized complete block design with three replications. Optimal sowing dates (02 October) and delayed sowing date (01 November) were assigned to the main plots, and 17 rapeseed genotypes [French (eight), Iranian (five), Hungarian (two) and German (two)] were randomized in sub-plots. Combined analysis of variance showed that all main and interactions effects were significant on all studied traits (except the main effect of year on seed oil content). Plant developmental stages experienced different environmental conditions due to delayed sowing and led to decreases in seed yield and yield components, seed oil yield and biological yield. The highest seed yield in optimal sowing date belonged to Garou (in the first year) and HL2012 (in the second year) genotypes with an average of 5240 and 5805 kg ha-1, respectively. However, Okapi (in the first year) and Garou (in the second year) had the lowest seed yield in delayed sowing date with an average of 3624 and 2702 kg ha-1, respectively. Lauren (in the first year) and Darko genotypes (in the second year) had the lowest grain yield reduction (%) in delayed sowing date which accounted for 21.5% and 35.9%, respectively.

Drought stress is one of the environmental factors influencing crops growth, development, and production. Two field experiments were performed in Karaj, Iran, to evaluate the drought tolerance indices of 17 winter rapeseed genotypes in 2015-2016 and 2016-2017 growing seasons. The factorial arrangement of treatments was set up as RCBD with three replications. To identify drought tolerant genotypes, several indices were used based on grain yield under normal and deficit irrigation conditions. Yield results showed that cultivars Artist (504.325 g m-2) and L72 (391.525 g m-2) were the superior treatments under normal and deficit irrigation conditions, respectively. According to correlation results, 3-D graphs were drawn based on Geometric Mean Productivity (GMP) and grain yield under normal irrigation and deficit irrigation to categorize the winter rapeseed genotypes in both years. In the first year, Zorica and Lauren were in group A, while in the second year; Mercure, SW102, L72, and HL3721 were in group A. Therefore, they had superior performance and stable grain yield under both irrigation conditions. Biplot diagram showed Lauren (first year) and Mercure (second year) were superior regardless of stress conditions. Altogether, under normal irrigation, Artist genotype, and under stress condition, Mercure, L72 and HL3721 genotypes could be used for cultivation.

In order to evaluate dry matter remobilization to seeds in the winter type rapeseed cultivars grown under drought stress conditions, an experiment was carried out using a randomized complete block design arranged in a split plot with three replicates in Shahre-Qods, Iran, in the 2011-2012 growing season. Irrigation treatments including control (irrigation after 80 mm evaporation from evaporation pan class A) and drought stress (irrigation withholding starting from stem elongation, flowering and silique formation stages) were allocated to the main plots and three winter type rapeseed cultivars (GKH2005, Opera and SLM046) were considered as the subplots. The results showed that drought stress increased dry matter remobilization and remobilization efficiency. By contrast, agronomic traits such as the number of siliques on the main stem and secondary branches, number of seeds per silique, 1000 seed weight, oil yield, harvest index and productivity effort (silique dry weight/biomass ratio) were decreased. The GKH2005 cultivar showed the maximum seed yield, which was 1058, 1409 and 2099 kg ha-1, when irrigation withholding started from stem elongation, flowering stage, and silique formation stages, respectively; this  was due to the higher amount of remobilization and the efficiency of remobilization and maximum number of silique in  the secondary branches. In general, the results suggest that higher remobilization and remobilization efficiency are among the most important drought stress tolerance mechanisms in the oilseed rape.

In order to evaluate the agronomic characteristics and some physiological traits of canola varieties under drought conditions, separate experiments were carried out at the Research Field of Yazd Agricultural and Natural Resources Research Center in 2011-2012. Each experiment was conducted in a randomized complete block design with three replications. In the first experiment (control) that was conducted under optimal irrigation, plants were irrigated based on 80 mm evaporation from pan class A at all stages of plant growth, in the second experiment, drought stress was applied at stem elongation up to maturity stage, in the third experiment, drought stress was performed at flowering up to maturity stage and in the fourth experiment, drought stress was performed at silique formation up to the end of maturity stage using three canola varieties including GKH2005, Opera and Okapi. The results of combined analysis showed that withholding irrigation started at stem elongation, flowering stage and silique formation reduced the silique number in the main stem by 44, 34 and 9 %, silique number per branches by 60, 34 and 17 %, seed number in silique per main stem by 62, 35 and 5 %, seed number in silique per branches by 73, 46 and 11 %, 1000- seed weight by 19, 28 and 26 % and seed yield by 62, 51 and 27 %, compared with the control conditions, respectively. The greatest grain yield was obtained from the control experiment as 3110 kg/ha and followed by withholding irrigation from silique formation, flowering stage and stem elongation with corresponding values of 2510, 1773 and 1450 kg/ha, respectively. Drought stress reduced the stomatal conductivity, relative water content (RWC) and cell membrane stability, whereas SPAD value was higher under drought conditions as compared with the control experiment. Under drought stress among studied cultivars, GKH had the maximum silique number, seed number in silique and seed yield due to the least electrolyte leakage percentage, higher stomatal conductivity and relative water content (RWC). The overall results of the experiments showed that withholding irrigation from silique formation owing to the reduction in irrigation frequency and efficient use of it in summer crops irrigation accompanied with the employment of drought tolerant varieties can be effective in increasing productivity and canola cultivation areas in arid and semi-arid regions.

Sowing date is an important determinant of yield in canola. Cultivation of winter rapeseed cultivars in semi arid regions of Iran however it has high potential for production، but، mentioned cultivars are late maturity and this late maturity cause to that silique formation and seed filling periods mature in the same time with hot and dry weather condition. In contrast، spring rapeseed cultivars are shorter growth duration and in this regard، identification of spring rapeseed cultivars with high cold tolerance for autumn planting cause to early harvest. In order to investigation of spring rapeseed cultivars reaction to spring and autumn planting dates، an experimental was carried out in a split plot design based on RCBD with four replications for two years (2004-2006) in Karaj. Treatments were included planting season in two levels as main plots such as common planting date، autumn planting (27 September) and spring planting (25 March) and spring rapeseed varieties as sub plots in 24 levels. The results indicated that simple effects of planting season and variety and also interaction effect on silique per plant، seed per silique، 1000 seed weight، seed yield، oil yield، biologic yield and harvest index were significant at 1% level probability. In autumn planting، Hyola 401 with greatest 1000 seed weight and high seed per silique had the highest seed yield (4689 kg. ha-1) and Hyola 330 produced the maximum oil yield (2165 kg. ha-1)، wherease RG 405/03 had the maximum seed yield and oil yield (2066 and 713. 6 kg. ha-1، respectively) in spring planting. On the basis of this result، some of spring rapeseed cultivars with high cold tolerance and high potential such as Hyola 401 could be planting in early autumn at moderate cold regions of Iran like Karaj.

To study the effects of different plant density on seed yield and yield components of three spring rapeseed cultivars a factorial experiment based on a Randomized Complete Block Design with three replications and 9 treatments was carried out during 2011 in Qazvin, Iran. Each plot consisted of 4 rows, 6 m long with 60 cm between rows. Seed were sown by hand (without pre planting irrigation) on February 2. Application of fertilizers, herbicides, pesticides and irrigation regime in this experiment were processed as they are usually done in the region. Three rapeseed cultivars Hayola401، RGS003 and Sarigol with three plant density levels (60, 80 and 100 plant/m2) were studied. At the end of growing period, traits like silique number per plant, seed number per silique and 1000 seed weight, seed yield and seed oil percent were measured. The results showed that plant density and cultivars affected silique number per plant, seed number per silique, 1000 seed weight and seed yield significantly. The effects of plant density by interaction on silique number per plant, seed number per silique and seed yield were also significant. Hayola401 produced the highest silique number per plant, seed number per silique, 1000 seed weight and seed yield. In these three cultivars under study the highest seed yield was obtained with the plant density of 80 plant/m2. Increasing plant density from 80 to 100 plants/m2 decreased silique number per plant, seed number per silique, 1000 seed weight and seed yield. This study showed that Hayola401 produced highest seed yield (1918/5 kg/ha) at plant density of 80 plant/m2.

To eveluate the effect of salicylic acid application under salinity stress conditions on physiologic and morphologic characteristics of artemisia, a factorial experiment based on Randomized Complete Block Design with four replications was conducted in Zanjan, Iran, during 2010-11. Treatments used were salinity four levels (0 (control), 4, 8 and 12 ds. m-1) and two levels salicylic acid (control and application of 0.5 mM). Traits measured were plant height, number of lateral shoot, seed yield of flowering shoots, antioxidant enzymes activity like catalas and superoxide dismutase, proline concentration and chlorophyll content of leaves were evaluated. The results showed that salinity stress decreased plant height, number of lateral shoot, seed yield of flowering shoots and chlorophyll content, and application of salicylic acid under both stress and non-stress conditions improved the above mentioned traits. Salinity stress also increased activity of antioxidant enzymes as well as catalase and superoxide dismotase and proline accumulation. Application of salicylic acid under both non-stress and salinity stress conditions decreased activity antioxidant enzymes and proline accumulation and reduced the effects salinity stress.

In order to evaluate the effect of increasing atmospheric CO2 concentration on salinity tolerance in rapeseed an experiment was conducted at the greenhouse of Tarbiat Modares University in 2010. The experiment consisted of three rapeseed varieties, four levels of salinity and three levels of atmospheric CO2 concentrations. Three levels of atmospheric CO2 concentrations (350, 700 and 1050 µmol mol-1), four levels of salinity (0, 5, 10 and 15 dS.m-1) were applied on three rapeseed varieties; Okapi, Zarfam, and RGS003. Three levels of CO2 concentrations were considered as three environments. Results indicated that CO2 concentrations had significant effect on shoot fresh and dry weight, leaf dry weight, plant height, leaf area, chlorophyll fluorescence, membrane ion leakage, and grain yield. Salinity had significant effect on shoot fresh and dry weight, plant height, leaf area, leaf specific weight, leaf relative water content, leaf chlorophyll fluorescence, membrane ion leakage, chlorophyll content and grain yield. The highest seed yield (2800 kg ha-1) was obtained in control and minimum (1130 kg ha-1) at salinity level of 15 dS.m-1.The CO2 concentration level of 1050 µmol mol-1 had the highest effect on shoot fresh and dry weight, leaf dry weight, plant height and leaf area, but no effect on grain yield. CO2 concentration had no significant effect on chlorophyll content. Effect of salinity on different traits of rapeseed varieties varied at different levels of CO2 concentrations and significant differences observed in leaf fresh and dry weight, shoot fresh and dry weight and membrane ion leakage. Membrane ion leakage increased with salinity, but was lowest in 1050 µmol mol-1 CO2 concentration and highest in 350 µmol mol-1. This study showed that elevated CO2 concentration could partially ameliorate some of adverse effects of salinity on vegetative growth of rapeseed, but not grain yield.

In order to investigate the effects of different weed control methods and moisture regimes on safflower (Carthamus tinctorius), a field split plot experiment based on randomized complete block design with 4 replications was conducted in Takestan Iran, during growing seasons of 2007-8. Three irrigations regimes (normal irrigation, restricted irrigation at stem elongation and restricted irrigation at flowering stage) were assigned to the main plots and nine chemical weed control method (complete hand weeding, treflan with 2 L/ha as pre plant herbicide, sonalan with 3 L/ha ad pre plant herbicide, estomp with 3 L/ha as pre plant herbicide, gallant super with 0/75 L/ha as post emergence herbicide, treflan with 2 L/ha as pre plant herbicide gallant super with 0/75 L/ha as post emergence herbicide, sonalan with 3 L/ha as pre plant herbicide gallant super with 0/75 L/ha as post emergence herbicide estomp with 3 L/ha as pre plant herbicide gallant super with 0/75 L/ha as post emergence herbicide and without hand weeding) to sub- plots. At the end of growing period traits like number of head per plant, number of seed per head, 1000 grain weight, percent of seed oil, yield of seed oil and grain yield were measured. Results indicated that treflan gallant super treatment in restricted irrigation at stem elongation stage had the lowest dry weight of weeds. In this study maximum grain yield (2927 Kg/ha) was achieved from hand weeding usual irrigation treatments. In general treflan gallant super treatment was the most effective treatment on safflower yield and weed control.

The effect of applying different methods and nitrogen levels on yield and essential oil of savagery (Satureja hortensis L.) was investigated using a factorial experiment based on randomized complete block design with 3 replications in 2005, Karaj, Iran. The treatments included application of solid nitrogen in soil with 4 levels 0, 50, 100 and 150 kg/ha and spray of nitrogen on foliage with 4 levels 0, 4.5, 6 and 7.5 percent. The nitrogen applied three times equally. The results showed, effect of treatments on biological yield, plant height, essential oil percentage, flowering shoot yield, number of lateral branch (P< 0.01) and harvest index were significant (P<0.05). Interaction of treatments on essential oil percentage, essential oil yield, flowering shoot yield (P<0.01) and biological yield (P<0.05) were significant. This experiment found that applying 100 kg pure nitrogen in soil with 4.5% produced highest biological yield, seed and flowering shoot with means of 4424, 875.3 and 1855 kg ha-1, respectively. The results showed, increase of nitrogen application caused decrease of essential oil percentage. Highest essential oil percentage related to application of 6% of nitrogen solution with mean of 2.13%. Utilization of 150 kg of solid nitrogen with 7.5% of nitrogen solution produced highest plant height with mean of 66.88 cm, highest lateral branch with mean of 18 and highest essential oil yield with mean of 33.7 kg ha-1. Highest harvest index related to control with mean of 25.98%. The results showed that use of sprayed nitrogen on foliage decrease nitrogen application. Therefore, this method could be suitable for sustainable agriculture.

In the present study eight symptoms of Plasmopara halstedii (Farl) Berl and de Toni including damping-off, sporulation on cotyledons and true leaves, sporulation on cotyledons, stunting, leaf mosaic or chlorosis, deformation, hypocotyls lesions and root reduction on the inoculated plants were compared as disease infection characteristics for assessment of resistance and suceptibility of sunflower cultivars and hybrids. Three days-old seedlings were inoculated with spore suspension of P. halstedii using whole seedling immersion method (WSI). Reactions of cultivars were recorded 15 days later. A strong correlation between the above symptoms, and sporulation on cotyledons and true leaves (SCL) as the main infection characteristic of the disease was determined. The most suitable regressional model for resistance determination was calculated based on mosaic (M), stunting (S), hypocotyle lesjons (HL) and root reduction (RR) symptoms. Among other regressional models tested for resistance determination, another model with high R2 value was also determined using only mosaic symptom.

In order to study the effects of Vesicular Arbuscular Mycorrhizae (VAM) fungi, phosphorus and drought stress on nutrient uptake efficiency in wheat, 3 factors of Mycorrhizae (with and without application), phosphorus (0, 6 and 12 g P2O5 per m2), and irrigation (10.5, 24.8, 36.1, 46.2 and 55.1mm water for each irrigation interval) were investigated on wheat (Mahdavi cultivar) with 3 replications based on Hanks et al. (1980). Application of fungus caused a significant increase in phosphorus and potassium uptake efficiency. The effect of phosphorus on above character was also significant at the 1% level of probability. There was not significant difference between application and non-application of fungus in nitrogen uptake efficiency, whereas application of different levels of phosphorus caused a significant difference at the 1% level on this character. Mean comparison of effects of fungus x phosphorus x irrigation on phosphorus uptake efficiency showed that symbiosis of phosphorus, had most phosphorus uptake efficiency (428.7gkg-1). The highest phosphorus uptake efficiency (295 gkg-1) without application of VAM fungi was obtained by use of 55.1 mm water for each irrigation interval and application of 6g P2O5 per m2.Therefore VAM fungi caused a significant increase for phosphorus uptake efficiency in low phosphorus levels.