فصلنامه پژوهشهای زراعی در حاشیه کویر
سال دهم شماره 3 (پاییز 1392)

In order to effect of weeds relative time of emergence on single cross 704 Corn (Zea mays) yield was studied in different density levels of the mentioned weed. The experimental design was split plot based on Randomized Completed Block Design (RCBD) with three replications in 2012 was carried out in Koohdasht, Lurestan. The emergence time was considered in 3 levels of E1, E2 and E3 (emergence of the weed 14 days earlier, 7 days earlier and simultaneously with corn, respectively) as main plots and density of weed in 6 levels of D1, D2, D3, D4 and D5 (0, 4, 8, 12, 16 and 20 plants per m2, respectively) as subplots. The height, laef area index (LAI) of corn decreased with earlier emergence time and increasing the density of the Weeds. Also, earlier emergence time of weeds at high densities lead to the reduction in yield component (ear length, diameter and weight, number of seed row in ear, number of seed in row and thousand seed weight). The results showed that a decreasing in grain and biological yield of Corn, as the emergence time of Corn delayed in comparison with the emergence time of weeds. The maximum reduction in grain and biological yield of Corn was observed in 14 days earlier emergence of weeds compared to Corn in high density of this weed (20 plants per m2) with 100 and 99 percent respectively, as Corn plants were put in canopies of weeds plants. Totally, based on the results of this research it can be stated that as the number of the earlier emergence days of weeds compared to the Corn increase, the competitive potential of the Corn reduces and an intense decrease is being observed in its yield. Though, the increase in density of the weed resulted in grain and biological yield reduction, there was no difference between the process of reduction in high densities of weed.

In order to study the effect of Azotobacter and Mycorrhiza symbiosis on protein percentage and some agronomic characteristics of safflower (Carthamus tinctorius L.), the experimental was conducted as factorial based of randomized complete block design in three replications during growing season of 20112012 in research farm of college of Arak Islamic Azad University.Treatments including of inoculated with Azotobacter in three levels (Non-inoculated, inoculation with Azotobacter-5 and inoculation with Azotobacter-12) and Glomus fungi treatment in four levels (Non-inoculated, inoculation with Glomus intraradices, inoculation with Glomus mosseae and inoculation with mixed G.intraradices and G.mosseae).The traits such as branching height, biological yield of sub-sub boll, harvest index of sub-boll, grain yield of sub-boll, saturation water deficit and grain protein percentage were measured. Based on the results of the variance analysis table, all characters except grain yield of sub-boll were significant as affected by main effect of Azotobacter and Glomus fungi of safflower. Also interaction effect of Azotobacter and Glomus fungi were significant on traits branching height, biological yield of sub-sub boll, grain yield of sub boll, saturation water deficit and grain protein percentage of safflower. Based on the mean comparison table, of the highest biological yield of sub-sub boll (30.50 gr.plant) related to treatment A2M3(inoculation with Azotobacter-12 and inoculation with mixed G.intraradices and G.mosseae) that showed significant differences, while the same treatment showed higher rates in grain protein content of safflower (19.44%). Also, highest grain yield of sub boll equal to (44.33 gr.plant) was obtained from treatment A1M3 (inoculation with Azotobacter-5 and inoculation with mixed G.intraradices and G.mosseae) and lowest equal to (33.28 gr.plant) was obtained from treatment A0M0 (non-inoculated with Azotobacter and Glomus fungi).

In order to study the effects of water deficit stress and foliar application of ascorbic acid, an experiment was conducted in research field of Islamic Azad University, Varamin Branch in Iran during 2012 growing season. The experimental design was laid out in a randomized complete block design with a split plots arrangement in three replications. Main plots included four different levels of irrigation (complete irrigation, irrigation withholding at 8-leaf stage, irrigation withholding at grain filling stage and irrigation withholding at both 8-leaf and grain filling stages) and three different concentration of Ascorbic Acid foliar application (0, 100 and 200 ppm) was allocated to subplots. The results showed that irrigation withholding conditions in different growth stages significantly decreased seed yield, biological yield, harvest index, oil and protein percentage, oil and protein yield and total chlorophyll content but by contrast increased proline content and superoxide dismutase activity in leaves. Foliar application of ascorbic acid as antioxidant enzyme could increased quantitative and qualitative yield and chlorophyll content and decreased proline and superoxide dismutase activity in leaves by reduction of water deficit stress. Foliar application of Ascorbic Acid with 200 ppm under irrigation withholding at both 8-leaf and grain filling stages increased 38/46% yield seed compared with treatment that foliar application without Ascorbic Acid. In addition, Ascorbic Acid foliar application reduced the harmful effects of water deficit stress as antioxidant and improved growth conditions for water deficit stress.

An experiment was conducted in order to evaluate the effects of Mo spraying on quantitative and qualitative characteristics of wheat grain yield under water stress condition, in varamin agricultural research center in 2010-11. A split plot layout within randomized complete block design with three replications were used. Main plots were three irrigation treatments (normal irrigation, non-irrigation at start of grain filling stage and non-irrigation at start of flowering stage) and sub plots were Mo spraying with three levels including spraying with pure water, Mo spraying with 0.5% concentration and Mo spraying with 1% concentration. The result showed that, grain yield and many of yield components affected by drought stress, significantly, on reproductive growth stage. Grain yield had significantly decreased by light and severe stress by 14.6% and 26.7% respectively. The most effect of stress at filling stage treatment were on thousand kernel weight leaf area duration and day to maturity, where as, number grain per spike and number of fertile ear affected with stress at flowering stage treatment. Severe stress treatment had a signifinant effect on maximum amount of LAI and CGR. Leaf area duration decreased for both two stress treatments and leaf defoliation started so earlier than normal treatment. Mo spraying has significant effects on grain yield and many yield components and also caused a significant decrease of water stress damages. 1% concentration of Mo spraying caused significant increase in total kernel weight, pedancle length, number of fertile spike and number of kernel per spike by 6.7%, 13.9%, 5.7%, 6.5% and 17.4% respectively. Day to maturity increased for 4 days in this treatment. Mo sprying with 1% concentration increased the grain yield from 5699 kg/hac to 6065 kg/hac significantly. There was no significant difference between to spraying concentrations (0.5% and 1%) for number of kernel per spike, total kernel weight, pedancle length, grain yield, biological yoeld, harvest index, protein yield and protein percentage. Also, the effect of Mo spraying was not significant for biological yield and harvest index. The manner of LAI and CGR changes during wheat growth period had significantly affected by Mo spraying. Protein percentage of wheat grain increased in both two irrigation and Mo soraying treatments.

In order to Evaluate effect of drought stress on Seed yield and water productivity in local and hybrid rice (Oryza sativa L.) varieties factorial experiment on the base of completely randomized design in 1389 in pot conditions.15 varieties of rice include local and breeding varieties in 3 irrigation conditions submerge, stress in vegetative stage and stress in reproductive stage were studied in four replication.Results of analysis of variance showed that interaction effects between irrigation and varieties for total characteristics 1% levels of probability. Results of mean comparison showed that highest seed yield was belonged to Sepidrood (65.18 gr.pot) and Hybrid (64.63 gr.pot) cultivars in submerge condition, Mohammadi (35.85 gr.pot) andDorfak (32.52 gr.pot) cultivars in vegetative stress condition, Mohammadi (37.51 gr.pot) and Sahel (32.48 gr.pot) cultivars in reproductive stress condition.seed water productivity and total water productivity in stress in vegetative stage and stress in reproductive stage, Mohammadi cultivar was resistance cultivar to drought stress.

This study was done to evaluate the effect of percent of wind sand (20,40,50,60) combined with farm soil on weight gain of the corms of Crocus sativus as well as its flowering yield in a field located at Gheshlagh village of Moin Abad of Varamin in 2010-2011. The experiment contained five treatments and was performed at a complete randomized block design with four replications. The corms were planted linearly in each row at the depth of 20cm and the distance of 7cm from each side. Irrigation was done in three times of 2010 October 7, 2010 November 6 and 2011 march 28 and the rows provided. Leaf pod and flowers present at each row were counted on a daily basis and the number was recorded daily. Average growth of the corms in each row shows significant difference p

In order to investigate the effect of manuring fertilizer and super absorbent under water deficit conditions on the morphological٫ quantitative and qualitative characteristics of soybean under water deficit stress condition an experiment were conducted with three replications in form of split factorial based on complete block design at field of Islamic Azad university, Varamin branch. Treatment were include water deficit stress (normal irrigation, limited irrigation after poding), manure fertilize (control, 15 tha-1and 30 tha-1) and super absorbent (control, use of super absorbent 15 kgha-1). irrigation treatment Was considered as main plot and manure fertilizer and super absorbent were placed factorialy at sub plot, The results showed that the simple effect of irrigation had significant effects on the branch number, first pod distance٫ pod number in branch, pod number in stem, pod number in plant, protein percent, protein yield, oil yield٫ biologic yield and Seed yield. The simple effect of manure Was significant on branch number, first pod distance, seed number in pod, pod number in stem, pod number in plant, oil percent, oil yield, protein percent, protein yield, seed number in plant, biologic yield and Seed yield. The simple effect of super absorbent Was also significant on first pod distance, pod number in branch, pod number in stem, pod number in plant, protein percent, protein yield, seed number in plant, biologic yield, Seed yield and harvest index. The triple interaction had a significant effect on pod number in stem, pod number in branch, pod number in plant, oil yield, protein percent, protein yield, seed number in plant, biologic yield and Seed yield. Water deficit decreased all plant characteristics compared to the normal irrigation, but application of super absorbent and manure fertilizer in water stress condition increased all morphological, quantitative and qualitative characteristics of soybean.

In order to evaluate the effect of water stress and zeolite application on yield and components yeild of winter wheat, this study was carried out in field of Arak University in Markazi province in 2009-2010. A split-plot arrangement of treatment in a randomized complete block design with three replications was used. Water stress (I0= Control irrigation, I1= Irrigation about 85% plant requirement water, I2= Irrigation about 70% of plant requirement water, I3= Irrigation about 55% of plant requirement water, were assigned in the main plots and different levels of zeolite application (Z0= without zeolite application, Z1= 3 ton ha-1, Z1= 6 ton ha-1, Z1= 9 ton ha-1) in sub plots. Each sub plot consisted of 4 rows, 5 m long with 50 cm between rows space and 5 cm between plants on the rows. In this study characteristics such as: plant height, number of grain per spike, 1000 grain weight, grain yield, Electrical conductivity of control treatment and Electrical conductivity of 50 degree water were assessed. Results indicated that un-stress irrigation (control irrigation) with average grain yield (5193 kg ha-1) and zeolite application (9 ton ha-1) variety with average grain yield (4901 kg ha-1) were significantly superior to the other treatments.