نشریه زراعت دیم ایران
سال چهارم شماره 1 (بهار و تابستان 1394)

To study the response of bread wheat cv. Azar2 to row spacing and seeding rate and to determine the desirable density under cold rainfed conditions a two-year study (2008 and 2009) was carried out in Qamloo research station located in Kurdistan. Four rows spacing including 15, 17.5, 20 and 25 cm as horizontal factor and four seeding rates including 350, 400, 450 and 500 seed/m2 as vertical factor were assigned. Row spacing had significant effect on grain yield, spike per square meter and harvest index. Seed rate was not significant except for thousand kernel weight. The highest and the lowest grain yield values, 3506 and 2624 kg/ha, were observed in rows spacing of 15 cm and 25 cm, respectively. Row spacing of 15 cm with 638 spike/m2 and 29 g TGW was located over the others. The highest grain per spike (22 grain) were observed in rows spacing of 25 cm. Because of no significant difference among seeding rates, the best recommendation of Azar2 planting type for cold high elevation rainfed areas is row spacing of 15 cm and seeding rates of 350-400 grain /m2 or 140-160 kg/ha.

In order to study the effect of conservation tillage on optimum usage of fuel and precipitation, this research was conducted in wheat-sunflower rotation in shahrood for 4 years. The experimental design was RCBD with 5 replications and 4 treatments (direct seeding (NT), reduced tillage (RT), conventional sowing with and without residue gathering (CT1 and CT2)). Results showed, Soil inversion difference was significant among the treatments (p<0.01). Maximum and minimum of Soil inversion related to CT and NT, respectively. In first year, Soil moisture content difference in various depths wasn’t significant among the treatments. Wheat yield difference was significant among the treatments (p<0.05). Maximum and minimum of wheat yield related to CT and NT, respectively. In 4th year, Soil moisture content difference in 5-20 cm was significant among the treatments (p<0.05). Maximum and minimum of Soil moisture related to NT and CT, respectively. Although wheat yield difference wasn’t significant among the treatments, but Maximum and minimum of yield difference related to RT and CT, respectively. Maximum and minimum of fuel consumption and operation time, related to CT and NT, respectively. Maximum and minimum of fuel consumption productivity, related to NT and CT, respectively. Regard to crop yield and fuel consumption productivity, In order to Soil moisture maintain and optimum usage of fuel in rain-fed conditions, it may be recommended that moldboard plough can be replaced by conservation tillage methods (reduced tillage & direct seeding).

In order to evaluate the effect of different levels of sulfur and manganese application on physiological characteristics of sunflower under different irrigation levels an experiment was conducted in agricultural research Institute of Kurdistan University in spring 2011. A split plot factorial experiment was carried out based on randomized complete block design with 4 replications. Main plot contain three levels of irrigation: 1- control (-3 bar), 2- mild stress (-8 bar) 3- severe stress (-12 bar), and sub plot were contained 2 factor as: 2 levels of sulfur application (1- no application and 2- 30 kg/ha) and the two levels of manganese application (1- control and 2- use of 1 kg/ha manganese). Results indicated that drought stress reduced gas exchange and photosynthesis. Use of sulfur and manganese increased photosynthesis in compared with control and increased chlorophyll b content. Drought stress caused to reduce in relative water content with damaging to cell membrane simultaneously. In drought condition the activity of Catalase reduced but Peroxidase activity increased. Manganese application caused to increase in Catalase activity. Finally fertilizer application could adjust the effect of drought stress to some extent.

In order to evaluate changes in the vertical distribution of leaf area and dry matter of wheat different cultivars in different densities of wild mustard, a field experiment was conducted in Agricultural Research Station Gorgan depended on Agriculture Research Center of Golestan Province during 2010-2012. The experiment design consisted of four randomized complete blocks in a factorial arrangement. The design consisted of two factors, four wheat cultivars (Arta, Tajan, Mogan and Morvarid) and 5 levels of wild mustard densities (0, 4, 8, 16 and 32 plants.m-2). The results of combined analysis showed year effect wasn’t significant on light extinction coefficient, light use efficiency, vertical distribution of leaf area and dry matter, but cultivar×wild mustard density interaction effect was significant. In this research distinguished dry matter accumulation and too leaf area amount in all of evaluated layers in Morvarid cultivar was higher than other cultivars in competition and pure conditions. Also, wheat cultivars in competition conditions assigned higher of leaf area and dry matter to the upper layers of canopy that this event was more evident in Morvarid and Moghan. In this research, the means of light extinction coefficient in the maximum of wild mustard density in Morvarid, Moghan, Arta and Tajan was 0.23, 0.51, 0.63 and 0.65, respectively. The highest and lowest of light extinction coefficient observed in Tajan and Morvarid, respectively. Totally, the results of this experiment in two years showed Morvarid had the highest of seed yield for the reason that the most of vertical distribution of leaf area and light use efficiency and too, the lowest of light extinction coefficient in compared to other cultivars, and was the more of succeed in competition with wild mustard.

The dryland areas of Iran are characterized by considerable weather variability, as well as major abiotic stresses, in particular drought and cold. Differentiation of Agro-climatically diversity, zoning of different areas need to take into consideration for crop suitability and management. In view of the very diverse climates, an agroclimatic zone map is of vital importance to achieve this purpose. The objectives of this study are to present Agro-climatically zoning differences for crop suitability usages. In order to do this study to indicate easily available information to agricultural producers, researchers and decision-makers were carried out. Data of monthly averages of precipitation, temperature, relative humidity, total incoming solar radiation and wind speed from the main stations were collected in Iran and data of neighboring countries were gathered from 1973 to 1998 analyzed by using UNISCO approach. Zoning maps on the basis of the three criteria: moisture regime, winter type and summer type indicated a total of 28 agro-climatic zones have been differentiated, from which only six (arid-cool winter-warm summer, arid-cool winter-very warm summer, arid-mild winter-very warm summer, semi arid-cold winter-warm summer, semi arid-cool winter-warm summer, and semi arid-cold winter-mild summer identified in where occupy nearly 90% areas of Iran. It can be concluded UNISCO approach is applicable and provide useful information for researcher and decision makers.

This study was carried out to determine effects of phosphorus residual applied to wheat on vetch (Vicia Panonioca) growth, yields and some soil physical, chemical properties in soil. The experiment was conducted with randomized completely block design in a field with three replications including four levels of P residual (applied for wheat P0, P15, P30, and P45 kg P2O5 in hectare) from Triple Super Phosphate fertilizer sources. Vetch seeds were planted at same place of planted wheat and applied P according to our package. After harvesting of vetch, plant samples were collected and soil samples prepared from 0-25 cm of soil depth. Results showed that phosphorus residual had significant effects on yields of seed and vetch biomass, number of cluster, root nodules, seed phosphorus concentration and uptake (P≤ 0.05), and weight of thousand vetch seed (P≤ 0.001). Phosphorus residual increased vetch growth significantly leading to increased soil organic matter, structural size and cation exchange capacity (P≤ 0.001). With increasing applied phosphorus fertilizer to wheat or soil phosphorus residual, vetch length, number of cluster, and number of effective nodules of vetch roots, also increased. Greater grain and biomass yields were observed in P45 treatment. It can be concluded that phosphorus residual can effect on P uptake and vetch growth and increase P uptake. In addition soil structural stability and cation exchange capacity improved by greater vetch growth. Vetch has also ability to use phosphorous residual from soil.

Cold tolerant safflower genotypes may be used as alternative winter crop in cold drylands of Iran. 56 selected genotypes of local safflower were tested under controlled and field conditions during winter 2013 and 2014. Genotypes were tested for their withstand remaining frozen for various freezing temperatures and different times. Survival of fully acclimated seedlings was evaluated after remaining frozen for 12 hours to 20 hours at -3°C which continuously decreased -2 in each hour up to -19°C. Survival after 12 hours at -3°C ranged from 0 to 100% and after 20 hours ranged from 0 to 20%. Selected materials were irrigated and germinated during fall planting in order to expose for winter cold in the field trial. There was a large variability among accessions for freezing tolerance in both controled and field conditions. Lethal temperature for 50% of the plants (LT50) with temperatures ranging from –3 to –19°C. All selected genotypes were fully germinated in the autumn however, the percent of green stand during spring and after winter damage was observed between 1 to 90 percent. There was a negative correlastion between LT50 and percent of stands in the spring. 15 cold tolerant genotypes were selected for further investigations.