فصلنامه اکوفیزیولوژی گیاهان زراعی
پیاپی 34 (تابستان 1394)

The soils of potato production fields in Ardabil due to alkalinity and not having a proper crop rotations are deficient in micronutrients. To evaluate the effect of these micronutrients on the yield and some traits affecting potato tubers an experiment was conducted in a complete randomized block design with three replications in Ardabil during 2012. Micronutrient treatments used were the various concentrations of iron and zinc (0.002¡ 0.004 and 0.008 concentrations of these elements as Fe1Zn1¡ Fe1Zn2¡ Fe1Zn3¡ Fe2Zn1¡ Fe2Zn2¡ Fe2Zn3¡ Fe3Zn1 and Fe3Zn2) and a control treatment (Fe0Zn0). Analysis of variance of traits under study showed statistically significant differences among treatments in terms of tuber yield¡ number of tubers per plant¡ tuber size¡ skin thickness and volumetric weight and dry weight of tubers. The highest tuber yield (48.10 t.ha-1) and maximum skin thickness were obtained from Fe1Zn3 treatment. The highest tuber number belonged to Fe2Zn1 (0.004 and 0.002 concentrations of iron and zinc) and Fe1Zn3 (0.002 and 0.008 concentrations of iron and zinc). Tuber weights higher than 35 grams and higest volumetric tuber weight were produced by using Fe3Zn2. The conclusion is this that using Fe1Zn3 traetment (0.002 and 0.008 concentrations) resulted in highest tuber yield and thickness of tuber skin.

To study the effects of multiple cropping systems on some characteristics of paddy field soil, this experiment was conducted by using a randomized complete block design (RCBD) with four replications at the Agricultural Research Center of Mazandaran for two years during 2009 - 2011 cropping seasons. The treatments consisted of four multiple cropping systems as: maize – clover - rice, maize – canola - rice, maize – broad been - rice and fallow - rice which were assigned to the plots. Results showed that pH and EC, were not significantly affected by multiple cropping systems, but the effect of multiple cropping systems on available organic matter, nitrogen, phosphorous and potassium were significant. The highest OM, total N and available P of paddy soil were obtained after maize – clover – rice.Highest available K was also obtained after fallow – rice cropping systems. The minimum OM, N, P and K content of paddy soil belonged to maize – canola – rice cropping system. Based on the climate and soil conditions of paddy fields in Mazandaran maize - clover – rice cropping system increased production and soil fertility more than other cropping systems.

To identify the most effective traits on corn yield by using biofertilizer under water deficit stress, an experiment was carried out in split plot based on randomized complete block design with three replications in Hashtgerd region in 2012. In this experiment, water deficit stress, as the main factor, consisted of four levels (control, stress at flowering, stress at grain filling and stress at both flowering and grain filling stages). Biological fertilizers as sub-plot consisted of four levels of biological fertilizer applications (control, application of Nytrazhyn, application of Barvar 2 fertile and application of both fertilizer Nytrazhyn and Barvar 2). Traits evaluated were seed yield, harvest index, 100 seed weight, number of ears per square meter, number of rows per ear, number of seed per row, weight, diameter and length of seeds. To determine the most effective traits simple correlation, stepwise regression analysis, path analysis and principal component analysis were performed. Multivariate analysis showed that harvest index, 100 grain weight and number of ears per square meter were highly effective on grain yield. They explained 77% and 66% of the total variance under both normal and drought stress conditions respectivly. The highest direct positive effect was related to harvest index under both conditions. To improving seed yielding potential of corn under water deficite cinditions emphasis should be placed mainly on the selection of genotypes with higher harvest indices.

This research was performed to evaluate genetic diversity for some quantitative traits and tuber flesh color of potato genotypes irradiated with gamma ray of Caesar cultivar, at the Agricultural Nuclear Research Institute of Karaj, Ardabil Behparvar Sabalan Company and Ardabil Agricultural and Natural Resources Research Station during 2012 and 2013. The plantlets were irradiated with gamma rays at dose of 25 Gy. The plantlets were sub-cultured three cycles in MS culture and then were transferred to the greenhouse. The 3000 plantlets were planted in plastic pots 10×10 cm with Mikskaar peat-moss and punce (1:1 v/v) in the greenhouse. From 3000 plantlets irradiated belonging to 175 genotypes, 1424 mini-tubers waghed 4821.7 g, were selected with selection intensity of 5.8%. Mean minituber numbers and their weights per plant of genotypes were 8.14 and 27.55 grams and in that of control were 4 and 17.4 grams respectively. The selected genotypes along with control (Caesar and Agria cultivars) were planted in an augmented design in 2013. The ANONA results showed that there were significant differences among genotypes for all traits under study. The tuber yield in parental genotypes was 27.42 ton.ha-1 and in genotypes 3-60 ton.ha-1, number of tubers and their weight per plant in parental genotypes were6 and 555 g. and in genotypes 2-28 and 60-1200 g. respectivly. The tuber yield, tuber number and weight per plant, tuber average weight and main stem number per plant had high diversity. In factor analysis, three independent factors explained 83.07% of the total variation. These factors were: 1- yield and its components (tuber yield, tuber number and weight per plant) as the first factor, 2- the tuber uniformity (average tuber weight) as the second factor, and 3- plant structure (p) and height and number of main stems per plant)as the third factor. The selected genotypes (46 genotypes) possessed higher tuber yields, tuber numbers and weight per plant, tuber uniform, shallow eye depth, skin and flesh color of yellow to dark yellow.

To evaluate the effects of foliar application of methanol on yield and yield components of bean under drought stress, a factorial experiment was conducted based on a completely randomized design with three replications at Khatam-Al-Anbia University of Behbahan. The first factor was different levels of methanol consisting of 0 (control), 10, 20 and 30 volumetric percentage (v/v), which were applied foliarly at three times with 10 days intervals during growing season of bean. The second factor was moisture regimes with three levels of irrigation at 25, 75 and 100 percent of field capacity. Results of this study showed significant differences among levels of methanol concentrations as to dry weight of pod, pod width and length, seed length and number of pod per plant. All of the yield components were mainly decreased by severe drought stress. As a whole, application of methanol did not increase yield of bean under drought condition.

To evaluate sugar-beet genotypes for their trait associations, two separate RCBD experiments with three replications were conducted both under non-saline (normal) and saline conditions at the Agricultural Research of Miandoab. Analysis of variance of the data collected showed that there were significant differences among genotypes for all traits studied under non-saline condition. But, differences of genotypes under saline condition were significant only for root yield, root potassium content, sugar extraction coefficient, impure and pure (white) sugar yields. Salinity stress, in this study, reduced root potassium content, root yield, sugar extraction coefficient, impure and pure (white) sugar yields. Mean comparisons of genotypes indicated that root yield of all genotypes, under non-saline condition, were higher than those of under saline one. As whole, genotypes number 1 and 2 produced higher root yields, impure and pure sugar yields respectively, under both saline and non-saline conditions. Based on the results obtained it was revealed that regression coefficients for the traits under study were significant. Step-wise regression and path coefficient analyses also indicated that traits like root yield, pure sugar and root nitrogen contents highly affected white sugar yield under non-saline conditions.

To evaluate the effects of different irrigation and nitrogen levels on variations of growth indices and corn (Single cross 260) seed yield, an experiment was conducted in a semi-arid area in Fars Province, Iran, during 2011 and 2012 growing seasons. The experiment was split-plot, based on a complete randomized block design with four replications. The main plots consisted of four moisture levels: (20% FC), (40% FC), (60% FC) and (80%FC) and sub-plot of four rates of nitrogen fertilizer applications: 150, 200, 250 and 300 kg.ha-1. Results showed that with increasing nitrogen fertilizer levels, LAI, NAR, SLA and RGR were also increased, but under lower moisture regimes they were decreased. The lowest and highest growth indices belonged to 80% and 20% water depletion, respectively. The lowest CGR index was obtained at 80% water depletion and 150 and 300 kg nitrogen ha-1. LAR increased at the intial growth period and then decreased. Positive relationships between seed yield and growth indices were also observed. At FC 20% and 300 kg N ha-1 treatment highest grain yield was obtained and growth indices were also in the highest values. In general, nitrogen application increased all traits. However, there were not significant differences between 250 and 300 kg N ha-1on the traits under study. It seems that nitrogen fertilizer mitigates the negative effects of water deficiency. Application of 250 kg of nitrogen fertilizer had the highest effect on all levels of moisture content.

This study was conducted to determine the yield stability of 10 cold region bread wheat genotypes, using a randomized complete block design with 3 replications for 4 years (2009-2013) at the Agricultural and Natural Resources Research Center of East Azerbaijan, Iran. Combined analysis of variance showed significant differences (p

To study the effects of physical seed primings on yield and alkaloid content of datura an experiment in a randomized complete block design with three replications and 10 different treatments was conducted at the Agricultural Research Station of Islamic Aazd University, Tabriz branch, Iran, during growing season of 2013. Treatments of moist seeds were: ultrasonic treatment of seeds with a maximum of 3 watts, gamma and beta irradiations of seeds at 2 microcurie (µc) for 10 minutes, laser irradiation at 6328 angstrom (A°) and magnetic field of seeds with 40 microtesla (mt) each for 5, 10, 15 minutes respectively and control. Results indicated that seeds treated with gamma irradiation increased plant height over the control by 45%. Highest (206 g.m-2) and lowest (108.3 g.m-2) biological yields were produced when seeds treated with magnetic field for 10 minutes and laser for 5 minutes respectively. Similarly, highest (27.27 g.m-2) and lowest (14.96 g.m-2) seed yields were obtained by treating seeds with magnetic field for 15 minutes and ultrasonic respectively. Alkaloid content in the above ground plant parts was highest when seeds treated with gamma irradiation and lowest with the magnetic field irradiation for 5 minutes. It may be concluded that physical primings of seeds with magnetic field, gamma and laser irradiations would result in higher seed yields.

To study the effect of different times of hand weeding, seed osmopriming and micronutrient foliar application on yield and yield components of corn (Zea mays L.) a factorial experiment based on randomized complete block design with four replications was carried out at the Research Farm of Shahrood University. Treatments factors were weeding with 3 levels (hand weeding 2, 4 and 6 weeks after crop emergence, seed osmopriming with 2 levels (osmopriming and control) and micronutrients application at 2 levels (foliar application with micronutrient and control). Results showed that the different times of weeding had significant effect on yield and yield components and highest seed yield was obtained with weeding at 6 weeks after emergence. Seed osmopriming significantly increased all of the variables under study. Foliar micronutrient applications also increased seed yield, biological yield, harvest index, height of plant, ear weght, ear length, ear diameter and the 100-seeds weight in comparison to control significantly, but it didn’t effect number of seed rows per ear significantly. The interactions of osmopriming and micro nutrient on grain yield, biological yield, harvest index, height of plant, the number of seed in row, 100-seed weight, weight of corn and ear length were also significant. The interactions of different times of weeding and osmopriming significantly affected only ear diameter. The effect of different times of weeding and foliar application of micronutrient on ear diameter was also significant. Seed yield and ear length were affected by triple interactions of treatments. The results of this study showed that osmopriming, foliar application of micronutrient and hand weeding 6 weeks after emergence all had positive effect on improving growth indices and seed yield of corn.

To determine the effects of foliar applications of some macroelements on castor seed yield and its components under drought stress conditions, an experiment was conducted at the Agricultural Research Center of East Azerbaijan province. A factorial experiment, based on randomized complete block design with three replications, was carried out during 2013 growing season. Treatment factors consisted of irrigations with two levels (no water deficit and water deficit during grain filling stage) and of foliar applications of macroelements with four levels [control, wettable sulfur (0.2 percent), nitrogen (urea: 0.6 percent) and phosphor (super phosphate triple: 0.4 percent). Traits studied were: plant height, number of inflorescence, number of lateral branches, number of leaves, leaf temperature, relative water content, number of seeds per plant, 1000-kernal weight and seed yield. All traits, except number of inflorescence, were affected significantly by drought stress. Water deficit reduced plant height, number of leaves, number of seeds per plant, 1000-kernal weight, seed yield, relative water content, while it increased leaf temperature. Number of lateral branches was affected significantly by interaction between factors. Maximum latral branches (1.86) were obtained under non-stress treatment with nitrogen foliar application. Moderate drought stress had significant effect on leaf temperature and relative water content. It seems that, these traits can be used in determination of water deficit effects on castor bean.