IRANIAN JOURNAL OF DRYLAND AGRICULTURE
Year:2019 | Volume:7 | Issue:2|Papers Count:6

An experiment was conducted to determine the effects of three tillage systems and no till in three crop rotations on soil physical properties, weed population and wheat yield in Tajarak Research Station (Kaboudarahang Township), Hamedan, as split plot experiment on the basis of RCBD with three replications in growing seasons 2012 to 2014. Tillage methods including (T1) conventional tillage (moldboard plow + cyclotiller equipped with roller), (T2) combination tiller (chisel plow equipped with roller), (T3) combination tiller (sweep plow equipped with roller) and (T4) direct drilling and crop rotations including: (R1) fallow– wheat, (R2) wheat– wheat (R3) chickpea-wheat were arranged in sub and main plots, respectively. Some of soil physical properties including: bulk density and cone index and also weed density, yield and yield components of wheat were determined. The results showed that crop rotations and soil tillage methods had not significantly effect on cone index and bulk density. The effect of crop rotation on weed populations was not significant, but the effect of soil tillage methods on this trait was significant. Conventional tillage (227. 1 kg/ha) and direct cropping (626. 8 kg/ha) had the lowest and highest weeds quantity, respectively. In dry year (2012-13), wheat grain yield under direct drilling was greater than conventional tillage.

In order to investigate the effect of plant density on the yield of two lentil varieties, Kimia and Bilehsevar, a split factorial experiment was conducted based on randomized complete block design with three replicates at Khodabandeh and Maragheh research stations during 2015-2017 growing seasons. Three row spacing (15, 20 and 25 cm) and six seed rates (150, 175, 200, 225, 250 and 275 seeds/m2) were considered. The results of combined analysis (two years and two regions) showed that the effects of areas, years and year × area interaction were significant for some traits such as days to flowering, days to maturity, plant height, 100 seed weight and grain yield at 1% probability level. The results showed that increasing of density up to 225 seeds/m2 increased the grain yield and more density than that had not significant effect on grain yield. Also, increasing seed density up to 200 seeds/m2 was improved the 100 seed weight and with increasing more than 200 seeds/m2 the seed weight was decreased. Increasing the row spacing from 15 to 25 cm reduced grain yield. According to the obtained results, it can be concluded that the best row spacing and seed rate for lentil is 15 cm and 200 seeds/m2, respectively.

In order to study the effects of various tillage methods on some soil physic-chemical properties, soil moisture maintain and sunflower performance, in Kalpoush dryland region of Miami, this project conducted as Randomize Complete Block Design (RCBD) with four replications in wheat rotation. Treatments were included, 1-moldboard plowing + disk harrow (CT), 2-reduced tillage with disk harrow (RT1), 3-reduced tillage with chisel plowing (RT2), 4-reduced tillage with chisel packer (RT3) and 5-direct seeding or notillage (NT). The results showed that at depths of 0-15 cm, soil moisture storage in conservation tillage was higher than the conventional tillage (P<0. 05). In the first and third years of the experiment, in the conventional method, compared with the no-tillage, the yield of sunflower was higher. In the final year (2016), the result was reverse. Combined analysis of 3-years on sunflower yield showed that conventional tillage and direct seeding were in the same class. In low precipitation year (2016), sunflower grain yield decreased in the conventional method but it increased a little in direct seeding method. In addition, soil moisture saving and precipitation use efficiency in direct cultivation was more than conventional method. Results of research showed that, after several years, grain yield of the sunflower has increased in conservation method and this may be an appropriate alternative to the conventional tillage method.

Several strategies have been developed in order to decrease water limitation effects under rain fed condition on plant growth. Among them, use of supplementary irrigation and nano iron oxide play a very important role on yield improvement. So, in order to study the effects of supplementary irrigation and nano iron oxide on growth indices, radiation absorption and yield of wheat under rain fed condition, a factorial experiment was conducted based on randomized complete block design with three replications in Agricultural Research Station of Ardabil in 2016. Factors of experiment were included irrigation in three levels (no irrigation as rain fed, supplementary irrigation at heading stage or according with 45 BBCH code, supplementary irrigation at booting stage or according with 61 BBCH code), foliar application of nano iron oxide in four levels (without nano iron oxide as control, foliar application of 0. 3, 0. 6 and 0. 9 g L-1). The results showed that 0. 9 g L-1 nano iron oxide application and supplementary irrigation at booting stage was caused the maximum of leaf area index, percentage of light absorbed, net assimilation rate, crop growth rate, relative growth rate and total dry matter compared to non-application of nano iron oxide under rain fed condition. Also, foliar application of 0. 9 g L-1 nano iron oxide and supplementary irrigation at booting stage increased grain yield by 38. 43% compared to no application of nano iron oxide under rain fed condition. Generally, it seems that application of supplementary irrigation and nano iron oxide can be considered as appropriate management factors for increasing grain yield under water limitation conditions.

In order to identify QTL associated with storage and remobilization of assimilates to grain, 72 barley double haploid lines along with Steptoe and Morex parents were evaluated in a simple lattice design with two replications under irrigated and water deficit conditions. Resulted based on composite interval mapping method revealed that under normal conditions, 17 QTL were significant for traits related to storage and remobilization of assimilates. The variance of phenotypes explained by this QTL varied from 11 to 20 percent. The highest and lowest phenotypic variances belonged to grain yield and allocation of photosynthetic to the stem, respectively and LOD ranged from 3. 02 to 6. 11. In water deficit condition, 14 QTL were detected. The phenotypic variance explained by this QTL varied from 11. 86 to 19. 77 percent, which belonged to remobilization of photosynthetic and allocation of photosynthetic to stems respectively. The LOD ranged from 3. 12 to 5. 61. In this study, allocation of photosynthetic to the stem two stable QTL detected on chromosomes 3H and 1H, for spike partitioning, a stable QTL on chromosome 4H, for remobilization of photosynthetic, two stable QTLs on chromosomes 4H and 1H and for the grain yield, two stable QTL on chromosomes 4H and 3H were identified. Recommended that after validation of the identified stable and clustered QTLs for significant quantitative and qualitative traits related to the storage and remobilization of photosynthetic materials and barley grain yield, these QTLs can be used in the marker selection program.

To evaluate genetic diversity of Kabuli chickpea genotypes under rainfed conditions in Entezary planting, an experiment was carried out in a randomized complete block design with two replications, in innovation platform of Iran-ICARDA Food Security Project located in Kamyaran city (Kurdistan province) during the year of 2016-2017. Based on the factor analysis, four factors were selected which 85. 7 percent of the total variation were explained. The first factor was explained 29 percent of variation which include plant height, the first pod height, the last pod height and 100 grain weight. The second factor was explained 28. 5 percent of variation which include number of pod per plant, number of seed per plant and grain yield. Therefor these two factors used to identify genotypes with high yield and yield components and genotypes 3, 4, 14, 15 and 16 were selected as high yield and yield component genotypes in Entezari planting. According to the result of cluster analysis based on morphological traits, the genotypes were classified into three groups. The genotypes of the first and the third clusters in most of agronomic traits and grain yield per plant had high average, compared to other clusters and genotypes average. According to the results of cluster analysis, we can use from genotypes of the first and the third clusters for producing hybrids with early maturity and high grain yield.