JOURNAL OF CROP PRODUCTION RESEARCH (ENVIRONMENTAL STRESSES IN PLANT SCIENCES)
Year:2011 | Volume:3 | Issue:1|Papers Count:11

Due to study the effect of planting date and seed priming on phenological stages, yield and yield components of sunflower varieties, an experiment was done as split factorial in the basis of randomized complete blocks design in 3 replications in research center of semnan (Shahrood). Planting date (20 Jun, 4 July and 19 July) as main plots and sunflower varieties (Azargol and Farah) and Seed priming methods (Osmopriming, Hydro priming and Control) as factorial considered as sub plots. The results indicated that, the main phonological sunflower stages as head emergence stage (R1), anthesis (R5) and Physiological maturity (R9), significantly affected by planting date, variety and priming. Interaction effect of planting date and variety was significant on head formation. Farokh had faster development stages than azargol variety. Delay in planting time deceased plant height, head height, stem diameter, head diameter and seed yield. Azargol was more succeed in plant height, head height, stem diameter, head diameter and seed yield than farrokh variety. The maximum seed yield gained in 20 Jun (1790 kg/ha), 4 July (1505 kg/ha) and the lowest one belonged to 19 July (774.7 kg/ha). Osmopriming (1441 kg/ha) and hydro priming (1375 kg/ha) treatments had the more seed yield than control (1253 kg/ha).

To assess the impact of soybean quality during various developmental stages (M7, M9.LODA) changes in day length and temperature of the modeling days to developmental stages in different courses, test using different planting dates in the summer 2009 Field research was conducted Agro meteorology Khorramabad to estimate the number of days to each stage, the number of days from sowing date until the 50% plot phase is considered as the dependent variable and variables, growing degree days (GDD) and photo thermal (PTU) as the independent variable in regression stage were placed on the stage of use Regression appropriate model was selected as the regression coefficients and constant coefficient model of diagnosis and at least 5% probability level is significant and has a maximum ratio of total recognition be. Days from planting to flowering, sowing and planting to pod week to investigate the effect of planting dates accepted. With increasing temperature decreased during the developmental stages of maturity from the influence of increasing day length and agreed it was reduced. Photo thermal variable alone was about 99.5% change and maturity in about 100% of days to flowering and pod changes week finally explained using the software SPSS, 9 for a three-stage model: days to flowering, days Submit to pod and maturity index soybean cultivation, delayed planting and soybean varieties were obtained and given that fixed GDD coefficients were significant in the models were excluded from the model. The purpose of this study models based on temperature and day length to estimate and predict various developmental stages and also to determine the climatic elements impressionable developmental stages for the development of soybean varieties were grown product.

In order to investigate of water deficit stress tolerance indices in four safflower genotypes (Carthamus tinctorius L.), this experiment was conducted in field research station of Islamic Azad University of Arak, Iran during 2008-2009. The experimental design was split plot based on randomized complete blocks design with four replications. The treatments composed of irrigation levels 100%, 75% and 50% crop water requirement as main plot and four safflower genotypes included Esfahan native, Esfahan-14, PI-537598andIL-111 as sub plot. Tolerance indices including: Mean Productivity (MP), Tolerance Index (TOL), Stress Susceptibility Index (SSI), Stress Tolerance Index (STI), Geometric Mean Productivity (GMP) and Harmonic Mean (Harm) were calculated. The results showed that the highest grain yield in optimum, moderate and severe stress condition was obtained from Esfahan native genotype. According to STI, MP, GMP, Harm indices Esfahan native genotype and on the basis of SSI and TOL indices IL-111 genotype in optimum and stress conditions were the higher tolerant to water deficit stress. STI, MP,GMP, Harm indices were showed correlation positive and significant with grain yield in optimum, moderate and severe stress condition. Therefore using STI, MP,GMP, Harm indices can selected genotypes with high yield in optimum and stress condition.

Sowing time and genotype are two important factors which influence crop performance including chickpea. In order to investigate the effects of autumn and spring sowing dates on chlorophyll content, intercepted radiation and leaf area index of chickpea genotypes a field experiment was carried out in Shahre-Rey region, in south of Tehran, Iran during 2009and 2010growth seasons. The experiment was laid out in factorial arrangement on the basis of randomized complete block design with four replications which five sowing dates (October 12, November 02 and November 22 as autumn sowing dates and March 16 and April 06 as spring sowing dates) and five chickpea genotypes (Arman, Azad, Hashem, ILC1799 and ILC482) were treatments. Results of combined analysis showed that effect of year on measured traits was not significant but effect of sowing dates, genotypes and these interactions were significant. The maximum leaf area index, intercepted radiation and chlorophyll b content were recorded in autumn sowing (November 22) nevertheless the highest chlorophyll a and total chlorophyll were observed in spring sowing (April 06). Among genotypes, maximum leaf area index, intercepted radiation and chlorophyll contents were obtained in Azad, ILC1799 and Hashem respectively.

In order to study the effect of withholding irrigation stress on some quantitative and qualitative characteristics of three sunflower hybrids an experiment was conducted in split plots based on randomized complete blocks design with three replications in farm located at the Behbehan agricultural research center station in 2010 cropping year. In this experiment, main plots were irrigation treatments including: complete irrigation, irrigation until heading stage (R5) and irrigation until grain formation (R6). Sub plots also were consisted of different hybrids of oil sunflower including: Euroflour, Azargol and Shf 81-196. Results showed that grain yield, yield components, biological yield, harvest index, oil content and oil yield were reduced significantly in response to drought stress severity. The maximal and minimal grain yield were obtained at desirable irrigation treatment and irrigation cutting time in heading stage with averages of 447.228 and 333.55 g/m2 respectively. The maximumoil andbiological yieldwereproduced at theoptimum irrigation treatment. These traits weresignificantly reducedwith increasingseverity ofdrought stress. Effect of hybrids on measured traits was also significant. The highestandlowestgrain yieldbelonged to Euroflour and Azargol respectively. The highestbiological yieldandharvest index were recorded at theoptimum irrigation treatment with Euroflourhybrid.

In order to evaluate the effects of Zn spraying and nitrogen fertilizer application on quantitative and qualitative characteristics of wheat grain yield under water stress condition An experiment was conducted in Varamin agricultural research center in 2009-2010. A split-factorial layout within randomized complete block design with three replications were used. Main plots were three irrigation treatments (Normal irrigation, Non-irrigation at 50% grain filling stage and Non-irrigation at 50% flowering stage) and sub plots were two Zn spraying (including spraying with pure water and Zn spraying) and Nitrogen fertilizer (with two levels including urea and ammonium solphat) treatments with factorial arrangment. The result showed that, all of yield components except plant height and biological yield, significantly affected by drought stress on reproductive growth stage. The most effect of Non irrigation at filling stage were on thousand kernel weight and spike length, where as, number grain per spike and number of fertile tiller affected with non irrigation at flowering stage treatment. The difference between two nitrogen fertilizer treatments was significant for all except pedancle and plant height. Zn spraying has significant effects on grain yield and many yield components and also caused a significant decrease of water stress damages. Protein percentage of grain increased because of a significant decrease of TKW. Zn spraying increased wheat grain yield through increasing the crop growth rate and leaf area index. The amount of Zn in grain, increased significantly in result of Zn spraying.

Drought is an abiotic stress that restrict water for agriculture. Due to study theEffect of plant growth promoting rhizobacteria, foliar application of amino acids and silicic acid on yield and yield components of wheat under drought stress conditions, an experiment was done in randomized complete blocks design with four replicates using analysis of split plot. This experiment was conducted with irrigation factor at two levels {A1: Control, A2: Cutirrigation after flowering stage} as main factor and the second experimental treatments at five levels {b1:Control, b2: Seed inoculated with bacteria (Azospirillum, Azotobacter, Pseudomonas), b3: Seed inoculated with bacteria (Azospirillum, Azotobacter, Pseudomonas) and sprayed silicilic acids, b4: Seed inoculated with bacteria (Azospirillum, Azotobacter, Pseudomonase) and sprayed amino acids and b5: Seed inoculated with bacteria (Azospirillum, Azotobacter, Pseudomonas) and sprayed silicic acids and amino acids}. The results showed that drought stress reduced the traits measured, but seed inoculated with plant growth promoting bacteria, sprayed silicic acid and amino acids in normal irrigation and drought stress conditions increased seed 1000 weight, spike length, number of spikelet per spike, number of seeds per spike, biological and seed yield. Also seed inoculated with plant growth promoting bacteria and combined silicic acid and amino acid application increased seed yield in normal irrigation and drought stress about %27.76 and %44.64, respectively.

In order to evaluate of suitable planting pattern for reduction herbicides dose in corn (Single Cross704) a field experiment was conducted at Faculty of Agriculture and Natural resources, Islamic Azad University, karaj branch in 2010. A factorial experiment was set up on base of randomized complete block design with 3 replications. Treatments include of corn planting pattern in 2 levels (single row and twin row), and herbicide treatments in 2 levels (Nicosulfuron and Foramsulfuron) and herbicide doses in 5 levels (0, 20, 40, 60 and 80 g ai/h) for Nicosulfuron and (0, 14, 28, 42 and 56 g ai/h) for Foramsulfuron. Density and dry weight of weed species were measured in 28 days after herbicide application. Results of statistical analysis showed that different herbicide doses had a various effect on weeds in each planting pattern. Using twin rows planting pattern could able to increase crop competition effect and suppressed weed growth in reduced herbicide doses. Nicosulfuron appeared better effect on weed control than Foramsulfuron. Environmental and economical advantages can be obtained by reducing herbicide doses, and selecting twin row planting pattern.