ruhollah naderi

at the seedling and adult plant stagesAegilops species are abundantly found in Iran, of which many could be resistant to wheat rusts .However, the researches that have been conducted to study their resistance and exploit them, are insufficient. Despite having different ploidy levels, some Aegilops species are similar in appearance and hence, flow cytometry was used to determine their ploidy level.  Three species i.e. Ae. crassa, Ae. neglecta and Ae. vavilovii were studied where Ae. tauschii (2n=2x=14) was used as a reference genome. The DNA content of the species Ae. crassa and Ae. neglecta was twice that of Ae. tauschii, and hence they were tetraploid (2n=4x) while DNA content in Ae. vavilovii was three times of the reference genome, and therefore it was hexaploid (2n=6x). To identify susceptible and resistant genotypes, a greenhouse study was conducted of 49 genotypes of Ae. crassa, Ae. neglecta, Ae. geniculata, Ae. kotschyi, Ae. biuncialis and Ae. vavilovii to wheat leaf rust at the seedling and adult plant stages. First, single spores of four pathotypes of Puccinia triticina were multiplied on the wheat susceptible cultivar “Roshan” to obtain pure and fresh urediniospores. Then, at the two-leaf stage, the plants were inoculated with these pathotypes and were kept at 20 ℃ under 100 % humidity for 24 hours in dark. Two weeks later, the seedlings were scored using the 0-4 scale where different infection types from completely resistant (0;=) to highly susceptible (3+) were detected. Additionally, at the adult plant stage, different levels of resistance (R to MR) were observed. This study lays the foundation for identifying the number of resistance genes in these genotypes and their modes of action in future studies.

Drought stress is the most limiting factor for producing wheat grain yield, especially in southern Iran. In order to recognize the most influential appropriate agronomic traits on grain yield of promising wheat genotypes (16 line) under normal irrigation and drought stress conditions, this study was conducted at Darab, Fars province in 2012-2013 and 2013-2014. Drought stress was started after anthesis and continued to physiological maturity. Days to physiological maturity was counted during growing seasons. At the end of growing seasons, 1000-kernal weight, grain no. per spike, spikelet no. per spike, floret no. per spikelet, tiller no. per unit area, crop height, grain yield, above ground biological yield (BY) and harvest index (HI) were measured. Four statistical methods including simple correlation, multiple linear regression, stepwise regression and path analysis were used for determined the relationship between the above mentioned traits and grain yield under the two irrigation treatments. Results showed that BY and HI for normal irrigation and for drought condition days to physiological maturity, BY and HI were the most important influential traits on yield. Based on the most statistical analysis, the BY role on grain yield was lower at drought condition than normal irrigation. Also, improving grain yield was attributed to HI under drought condition.

     Several factors affect the crop yield and weeds are among the most important factors reducing crop yields .There are high tendency to develop alternative methods of herbicides for natural control of weeds in organic products. One of the alternative methods to manage weeds is intercropping. Intercropping is growing two or more crops simultaneously in a piece of land during a growing season. The objectives of the present study were to examine the effect of cereal- legume intercropping on weeds growth. A field experiment was conducted in College of Agriculture of Darab, Shiraz University during 2014-2015.      In the experiment 16 treatments (five weed free monocultures of wheat (M1), barley (M2), triticale (M3), pea (M4), faba bean (M5), 5 weedy monocultures of wheat (WM1), barley (WM2), triticale (WM3), pea (WM4), faba bean (WM5), and six replacement intercropping treatments of wheat + pea (I1), wheat + faba bean (I2), barley + pea (I3), barley +  faba bean (I4), triticale + pea (I5) and triticale + faba bean (I6) without weed control) using a randomized complete block design (RCBD) with three replicates were studied. Cereals and legumes were planted simultaneously at 23 November 2014. Planting operation was conducted on both sides of the ridges.    Weed diversity was calculated by Shannon diversity index:     N=Total number of plants in each plot of one square meter, Ni= number of species i plants, S= total number of species, and H= Shannon diversity index. This index value ranging from zero to five, higher index value, greater diversity.      The results showed that the lowest density and biomass of weeds were obtained in both sole culture and intercropping of barley. For instance, the lowest weed biomass was observed in monoculture of weedy barley (1 g m-2), intercropping of barley + faba bean (12.67 g m-2) and intercropping of barley + pea (56 g m-2). The weed density at weed free sole culture of barley (30 plants m-2) was lowest that followed by barley + faba bean intercropping (81 plants per m-2). The lowest species weed diversity was obtained in barley + pea (zero) and weedy barley (0.007), respectively. The weed diversity of most intercropping treatments was similar or less than that of weedy sole culture. In General, pea or faba bean monoculture had greatest weeds density and biomass, because slow growth and late seedling establishment. However, cereals especially barley controlled weeds properly, due to greater growth rate, higher height and greater density than those of legumes. Intercropping of pea and faba bean with cereals reduced weeds growth and had lower weeds density and biomass than those of pea and faba bean weedy monocultures. In order to increase of legume yields, more density of legume should be intercropped with cereals.      In general, intercropping treatments caused a significant decrease in weeds density and biomass compared to the legumes monoculture. In this experiment barley and triticale due to good properties such as fast growth, high plant height and more shading could considerably control weeds in both monoculture and intercropping treatments, reducing significantly weeds density and biomass in itself sole culture and intercropping treatments. To reduce the weeds growth in faba bean and pea, which have a poor competitive ability with weeds, intercropping with cereals, especially barley and triticale, in the south of Fars province is recommended. However, intercropping is one of the ways to reduce weeds in the long term and its effects on weeds in the long period will be much more.     The authors would like to acknowledge the College of Agriculture and Natural Resources of Darab, Shiraz University, to finance the project and all those who helped us in this project.

The detrimental drought effects could be listed as the loss in dry weight and silicon is known to enhance crop tolerance to drought by increasing seedling growth and hydraulic conductivity. To investigate the effects of silicon priming (0, 1 and 2 mM as sodium silicate), on seedling growth and root anatomy of three barley cultivars (Khatam, Rihane, and Nimrooz) a laboratory experiment was conducted under drought stress induced by 3.6 mM polyethylene glycol (PEG). Under 3.6 mM PEG, the highest root length was observed in Nimrooz barley cultivar (7.86 mm) at 2 mM silicon. In Nimrooz, seedling dry weight increased from 0.19 mg plant-1 in control to 0.27 mg plant-1 at 2 mM silicon (29.6% increase). At 2 mM silicon, Nimrooz with highest root surface area had the highest hydraulic conductivity (6.29×10 -9 m s-1 MPa-1) while in Rihane and Khatam was low as 5.38 and 5.19×10-9 m s-1 MPa-1 under 3.6 mM PEG, respectively. In Nimrooz, positive relationship was observed between application of 2 mM silicon and increasing the mean diameter of peripheral metaxylem vessels under drought. In all barely cultivars, drought stress affected the diameter of the vessels more than the number of the vessels. Also, under 3.6 mM PEG, K+ and Ca2+content increased from 0 mM silicon to 2 mM. Overall, silicon priming at 2 mM, especially in Nimrooz appears to be a promising and cost-effective procedure to alleviate the drought stress.

To investigate the amount of nitrogen (N), phosphorous (P) and potassium (K) uptake in crops and weeds in cereals-legumes intercropping, a field experiment was performed in 2014-2015. Treatments included 10 monoculture (wheat, barley, triticale, pea and bean with and without weeds) and 6 intercropping (wheat pea, wheat faba bean, barley pea, barley faba bean, triticale pea and triticale faba bean with weeds) which laid out in a randomized complete block design (RCBD) with three replicates. Our results showed that the highest N content in cereals shoot was obtained in weed-free monoculture wheat (8.1 %) and in legumes shoot was obtained in weedy monoculture pea (17.3 %) and weed-free monoculture pea (15.8 %). There was no significant difference between weedy monoculture and intercropping treatments for N content in weed shoot, according to Duncan test. The highest value of P content in cereals shoot was observed in faba bean숗 intercropping (0.80 %) and weed-free monoculture wheat (0.79 %). The highest amount of P content in legume and weeds was obtained in weed-free monoculture pea (1.90 %) and weedy monoculture pea (0.13 %). The highest amount of K content in cereals, legumes and weed shoot was obtained in barley-pea intercropping (1.95 %), triticale-pea (1.59 %) and barley-pea (1.90 %), respectively. Thus, intercropping can reduce nutrients availability for weeds and it can cause an increase in nutrients for crops.

In order to investigate the response of cereals to intercropping with legume in weed competition conditions, a field experiment was performed in 2014-2015 in the College of Agriculture and Natural Resources of Darab, Shiraz University. Treatments included 10 monoculture (wheat, barley, triticale, pea and bean with and without weeds) and 6 intercropping (wheat + chickpea, wheat + faba bean, barley + chickpea, barley + faba bean, triticale + chickpea and triticale + faba bean with Weeds) which laid out in a randomized complete block design (RCBD) with three replications. Results showed that grain yield, biological yield and harvest index in most intercropping treatments was similar to those in weedy monoculture and even in some cases similar to those in weed-free monoculture treatments which it shows that intercropping had a higher efficiency. For instance, grain yield in barley+ chickpea intercropping (6241 kg ha-1) and barley+ faba bean (5333 kg ha-1) was not significantly different from weedy barley monoculture (7313 kg ha-1) and weed-free barley monoculture (7621 kg h-1). Partial LER of cereals, in intercropping treatments except wheat+faba bean (0.39) based on weedy monocultures, was greater than 0.5 and also except intercropping of triticale + chickpea (0.31) and wheat + faba bean (0.41) based on weed-free monocultures was more than 0.5. Barley had a greatest grain and biological yield over all the treatments which it was because of its superior competitive ability against weeds.

In order to investigate the persistence of organic amendments, nitrogen and zinc effects on soil characteristics in rapeseed-wheat rotation, a factor analysis was conducted in a complete random design with three replications in two consecutive years in a greenhouse. Treatments in the first year consisted of N fertilizer, municipal waste compost, vermicompost, sheep manure. The control consisted of zinc and two rapeseed cultivars. In the second year of the experiment, two cultivars of durum wheat were sown in the same pots as the first year of the experiment. Results showed that two years after application of cattle manure, a significant increase in soil electrical conductivity (41.81 %), available K (59.45 %) and available Mn (79.82 %) compared to the control were found. Saturated soil moisture (48.57%), total N (94.66 %), available Fe (46.49 %) and available Cu (47.51 %) significantly increased by municipal waste compost compared to the control. Also, Zinc had a significant effect on soil total N (0.28 %), available K (218.4 mg/kg) and available Mn (12.89 mg/kg). Generally, the results showed that application of organic amendments can change many soil characteristics which some of their impacts might last for next upcoming years. Therefore, it is necessary to monitor the soil characteristics and nutrients availability of the fields that were treated with organic amendments in the years after application.

IntroductionCereal-legume intercropping is one of the best ways to increase the yield per unit area (to decrease the detrimental effect caused by weeds and to reduce application of fertilizers and herbicides. Stoltz et al. (2014) in a study on corn-pea intercropping reported that crops yield in intercropped plots was significantly greater than that of monoculture. It has been reported that barley-faba bean intercropping led to an increase in total grain yield and it could cause a decrease in weed biomass. Considering the importance of intercropping to reach stability and sustainability in production, the aim of this study was to assess the changes in yield and yield components of faba bean and pea in intercropping with wheat, barley and triticale under weedy conditions in southern Fars Province.
Materials & MethodsA field experiment was performed in the College of Agriculture and Natural Resources of Darab, Shiraz University during 2014-2015. Treatments included 10 monoculture (wheat, barley, triticale, pea and faba bean with and without weeds) and 6 intercropping (wheat pea, wheat faba bean, barley pea, barley faba bean, triticale pea and triticale faba bean with weeds) which laid out based on a randomized complete block design (RCBD) with three replications. Irrigation intervals were 8 and 12 days based on environmental conditions. Weeds were hand weeded twice, at tillering and booting stages of cereals. After crop maturity, plants were hand harvested to measure yield and yield components. Additionally, partial land equivalent ratio (LER) was calculated. The partial land equivalent ratio has been defined as a measure of efficiency of an intercrop or mixture. The LER compares land areas required under single or sole cropping to give the yields obtained from the component crops of the mixture. Values greater than 0.5 indicate intercropping to be more efficient than sole cropping in terms of land use, while values less than 0.5 indicate a loss in efficiency due to intercropping. Values equal to 0.5 indicate that the components fully share the same limiting resource. The data analyzed by using MSTATC ver2.10 software (1991). Since the number of the plants was not similar in all the plots, the data was subjected to analysis of covariance.
Results & DiscussionResults showed a significant effect of treatments on 1000-seed weight of pea, number of pod per m2, number of seed per pod, grain yield, biological yield, harvest index and LER. The greatest 1000-seed weight of pea, number of pod per m2, seed yield and harvest index obtained in intercropping of wheat pea (366.7 g), weed-free pea monoculture (1317), weed-free faba bean monoculture (4149 kg/ha) and weed-free faba bean monoculture (46.46 %), respectively. The highest number of seed per pod was obtained in intercropping of barley faba bean (3.7), weed-free faba bean monoculture (3.29) and intercropping of wheat faba bean (2.93), respectively. Total and partial LER of legumes in all intercropping treatments compared to weedy monoculture was greater than 1 and 0.5, respectively. The results showed that weed-free monoculture treatments had the highest grain yield, biological yield and harvest index. However, crop yield and harvest index in intercropping treatments were similar or superior to weedy monocultures. For instance, grain yield and harvest index in intercropping of wheat faba bean was higher than those of in weedy faba bean monoculture, 102 and 93 %, respectively. In general, grain yield, biological yield and harvest index of pea and faba bean in weed-free monocultures treatments was higher than weedy monocultures and intercropping treatments. Grain yield and harvest index of intercropping was similar or higher than those of weedy monocultures.
ConclusionTotal and partial LER of legumes in all intercropping treatments compared to weedy monoculture was greater than 1 and 0.5, respectively. Since cereals are more competitive than legumes, it seems for increasing the efficiency of intercropping; a higher density of legumes should be used. Additionally, for reducing weed interference and increasing yield in pea and faba bean, the use of cereal-legume intercropping is recommended.

To investigate the effect of organic amendments and zinc on grain yield of rapeseed and wheat, nitrogen and zinc uptake of wheat in a rapeseed-wheat rotation, a two-year study was conducted at the Agricultural college of Darab, Shiraz University in 2012-2014.In the first year of the study, treatments consisted of nitrogen fertilizer, municipal waste compost, vermicompost, sheep manure, cattle manure, and control (no fertilizer) and zinc sulphate rates of 0, 10 and 20 mg kg-1 and two rapeseed cultivars (Sarigol and RGS). In the second year of the study, in the same pots as the last year two durum wheat cultivars (Behrang and Yavarus) were sown. Results showed that sheep manure increased rapeseed yield more than the other fertilizers. Also, grain yield of Yavarus was higher than that of Behrang. The greatest grain yield observed in sheep manure treatment (5.71 g pot-1). The residual effect of sheep manure on wheat yield was more than the other organic amendments. All organic amendments except vermicompost increased nitrogen content in wheat grain significantly compared to control and the highest amount of zinc in wheat grain obtained in sheep manure treatment (39 mg kg -1). Results showed that the different rapeseed and wheat cultivars showed various responses to organic amendments and chemical N fertilizers and the type of cultivars should be taken into account while recommending these fertilizers.

Excessive use of chemical herbicides has resulted to many problems such as adverse environmental impacts, contamination of groundwater and resistant weeds. Therefore, researchers are looking for solutions to reduce the use of herbicides as more as possible. One effective approach is to use the characteristics of allelopathic plants. To evaluate the allelopathic effects of extracts of madder on seed germination of several crops (corn and sorghum) and weeds (Johnsongrass and field bindweed), four separate laboratory experiments were conducted in 2011 at Yazd University of Applied Science. The experimental design was a completely randomized with 4 replications and 5 treatments. Treatments were madder extract at 5 levels (zero, 25%, 50%, 75% and 100%, respectively). The results showed that the extract of madder could decrease traits such as germination percentage and germination rate, root and shoot length, root to shoot ratio (R / S), seedling vigor index and total dry weight of all plants significantly (p

The crop water stress index (CWSI) is a valuable tool for monitoring and quantifying water stress as well as for irrigation scheduling. A field experiment was conducted during spring and summer 2012 at Research Station of College of Agriculture and Natural Resources of Darab, Shiraz University, Iran, to determine CWSI of turfgrass for irrigation scheduling. Four levels of water regimes including well watered [Irrigation according to 100% field capacity (FC)], mild drought stress (75% FC), severe drought (50% FC), and most severe drought (25% FC) stress were arranged in a randomized complete block design with four replicateions. The highest monthly average value of CWSI for all treatments was reached in August and decreased in September slightly. In all treatments the CWSI values showed an increasing trend from June (0.097 in well watered treatment) to August (0.684 under most severe drought) as a result of higher vapor pressure deficit values and negatively increase in Tc-Ta differential. Also, significant differences were observed between mean CWSI values of well watered and mild drought, with severe drought and most severe drought treatments. The color grading number for mild drought treatment in turfgrass decreased sharply from 8 to 4 at the start of the experiment in July, and remained constant (3) for August and September. The amounts of irrigation water more than 75% FC did not affect visual quality of turfgrass, which appeared to be sufficient to fulfill an acceptable turfgrass quality. A negative relationship was found between CWSI with water applied and color quality under different irrigation regimes. It appeared that under arid and semi-arid conditions, such as southern Iran, where the amount of water is a major limiting factor, the amount of applied water could be lowered to 75% FC without any loss in visual quality of turfgrass with the seasonal CWSI being kept about 0.15.

Salinity is one of the major abiotic challenges influencing plant productivity worldwide. To examine the response of two alfalfa cultivars (Bami and Hamedani) to six levels of water salinity (0, 25, 50, 75, 100, 125 mM L-1 NaCl), a glasshouse experiment was conducted at the College of Agriculture, Shiraz University, Shiraz, Iran in 2008. The results showed that in Bami (which appeared to be more tolerant to salinity), with increasing salt stress from 7 to 125 mM L-1, dry weight per pot was significantly decreased from 15.1 to 10.3 g, while in Hamedani decrease in dry weight was started from 50 mM L-1 salinity level. In both Bami and Hamedani cultivars leaf area per pot was significantly decreased when salt stress was higher than 75 mM L-1. There was a significant difference in leaf relative water content (RWC) between the two alfalfa cultivars in 75, 100 and 125 mM L-1 NaCl salinity levels. With increase in salinity level, the Na+ concentration was increased from 220 to 565 mmol kg-1 dry weight in Bami, and from 238 to 643 mmol kg-1 dry weight in Hamedani. The Cl- concentration in Hamedani (622 mmol kg-1 dry weight in 125 mM L-1 NaCl) was higher than that in Bami (503 mmol kg-1 dry weight in 125 mM L-1 NaCl). The K+ concentration was increased from 203 to 604 mmol kg-1 dry weight in Bami, and from 135 to 571 mmol kg-1 dry weight in Hamedani. Furthermore, phytomass production in Bami was significantly correlated with K+ (r=0.97), and Ca2+ (r=0.96) concentrations, as well as with leaf area (r=0.50) and plant height (r=0.87). Path analysis showed that there were significant direct effects of leaf area (p=0.73), Ca2+ (p=1.02) and K+ (p=0.59) on dry weight in Bami. In Hamedani, there were significant direct effects of K+ (p=0.61) and Ca2+ (p=1.07 on dry weight. Overall, based on both correlation and path analyses, it was concluded that measurements of K+ and Ca2+ concentrations may be appropriate criteria for evaluating susceptibility of cultivars to salt stress. These results may also be used for screening the salt resistant cultivars of alfalfa.