CROP PRODUCTION IN ENVIRONMENTAL STRESS
Year:2013 | Volume:5 | Issue:1 (SERIAL 12)|Papers Count:6

In order to affect some micronutrient elements on grain yield and yield components of rice cultivars Local-Tarom, an experimental farm in 2010 as the city of Amol in factorial randomized complete block design with four replications was performed. Three essential micronutrients zinc, copper and manganese, each at two levels, including no use (control) and consumption of 20 kg/ha as source sulfate were. The results showed that the total number of tillers per hill of statistical affect any of the treatments was not included. Fertile tillers per hill, the total number of spikelet and filled spikelet per panicle and 1000-grain weight by taking zinc sulfate 4.9, 3.5, 5.9, 3.1 percent, respectively. As a result increased yield on the 4.9 percent has been added. Harvest index due to the consumption of zinc sulfate 3 percent reduction in straw yield increased. Grain yield, harvest index and yield components of all statistically were not affected by manganese. Straw yield with manganese sulfate consumption decreased 2 percent. Grain yield with consumption of copper sulfate 5.2 percent was reduced because the grain weight than 3.9 percent was lower. Consumption of copper sulfate increased straw yield ratio 3.7 percent has been the result of the harvest index was also lower. The most grain yield, harvest index, and lowest straw yield under the three factors for treatment interactions with the consumption of zinc sulfate and without taking copper and manganese.

Anisum (Pimpinella anisum L.) is one of the aromatic herbal plants which has great export value. In order to investigate effects of drought stress on yield and essential oil in different populations of Anisum an experiment was conducted in alborz karaj stations in 2011. This research was caried out as a randomized complete block design with 4 replications. Main factors were 3 populations of the Anisum (sabzevar, kerman and jiroft) and sub factors were include 4 levels of drought stress (10, 30, 50 and 70 % water depletion). Effect of interaction between main and sub factors were different significant on essential oil stem at %1 level and stem yield, dry matter yield and essential oil yield at %5 level. Mean comparison of main and sub factors showed that highest root yield, stem yield and dry matter yield order 120, 712 and 1100 kg/ha belong to kerman population in 10% water depletion and highest essential oil stem (0.89%) and essential oil leaf (0.63%) belong to kerman population in 70% water depletion.

To determine salinity tolerance of wheat (Triticum aestivum L.) at various growth stages, a controlled experiment (lysimeter conditions) was conducted at the National Salinity Research Center. Experimental design consisted of six treatments replicated three times in a randomized complete block design. Treatments were application of salinity at establishment stage, tillering, stem elongation, spike emergence, during grain filling period till final growing season and without imposing salinity (control). Wheat plants were grown in eighteen boxes (0.5×0.4 m and 0.5 m depth) contained washed sand. Plants were irrigated 2-4 times daily using nutrient solution. The results showed that from emergence to tillering and from emergence to stem elongation phases were two sensitive stages of wheat growth to salinity stress and spike length and plant height were reduced significantly. Biological yield was considerably reduced by imposing salinity at establishment stage through growing season. Delay in application of salinity was associated with lower reduction in biological yield. Salinity reduced grain yield more severely when salinity stress was imposed at earlier stage of growth. Based on the results reduction in biological yield and the number of plants per unit area were the main contributing factors in grain yield reduction under salinity stress conditions.

To evaluate the eco-physiological adaptation of many wheat genotypes against drought stress and determination of tolerant genotype, this experiment was carried out in Randomized Complete Block Design with three replications and 50 genotypes, under both irrigation and dry land conditions, in agricultural research station of Shirvan-chardavol in Ilam province, during cropping season 2010-2011. The results indicated that under dry land conditions, number of spikelet and 1000 kernel weight with seed yield had a positive significant (p<0.01) correlation. Under irrigation conditions, seed yield had a positive and significant correlation with number of seed in spike, height of peduncle, 1000 kernel weight and harvest index. Based on kernel yield of wheat genotypes at irrigation and dry land conditions, mean productivity (MP), stress susceptibility index (SSI), stress tolerance index (STI) and geometric mean productivity (GMP) were calculated. Regarding to this study indicated that MP, GMP and STI indices had the highest correlation with kernel yield and these criteria were recommended as desirable indices to determine the resistant wheat genotypes. In conclusion: Mohammadi, Cross-e-Sabalan and Sardari varieties were the best and most tolerance ones and had the highest yield under both irrigation and dry land conditions.

To evaluate the effect of domestic sewage drain on morphological characteristics and yield of essential oil of chamomile plant in water stress conditions, in the randomized complete block design (RCBD) with four replications was conducted at the Islamic Azad University Shahr-e-Qods branch. In this experiment three ecotype populations from Karaj, Kerman and Wild Chamomile that have been collected by the Agricultural Research Center of Esfahan were used. Results showed that the impact of irrigation with drain wastewater on plant height, number of flowers, flower dry weight, stem diameter, oil content, number of main stems, flowers fresh biomass was significant. Maximum height and fresh flowers weight obtained from treatment that provide 100% plant water requirement and the other treatments in reducing the amount of moisture available to the plant during its downward trend and in 55% of treated water needs to be minimized. Drought stress caused a significant effect on oil yield and its contributing traits like oil content, fresh flowers, dry flowers and flower number. Use a mild stress of 85% and 70% of the chamomile plant water needs, beside water saving, will be produce reasonable chamomile essential oil and acceptable performance.

This experiment done in two fields of soil medium with high (>15ppm) and low (7ppm) phosphate availability, experiments were based on the split split plot in carried out completely randomized block design using three replications in Fars province of Iran, 2011. Treatments consisted of; halt of irrigation in main plots in there levels: without stress (Control), halt irrigation at the end of vegetative stage (R1: silking) and halt irrigation in the middle of reproductive stage (R2: blistering). PSB treatments were in sub plots in 3 levels: none PSB application (Control), PSB sole application and conjunctive application of PSB with half of the recommended chemical phosphorous fertilizer based on soil analysis and implementation of seed priming treatments in sub-sub plots in four levels: Dry seed (Control) GA3, IAA and hydro primed seeds. Results showed that interaction effect of halt irrigation and seed priming in two fields GA3 priming and without stress acted to enhance length and diameter of ear, thousand-kernel weight, number of kernels per row, number of row per ear, number of kernels per ear and grain yield and biological yield. The interaction effect of irrigation halt and PSB application showed that, the highest value for all the measured traits were acquired in treatments with complete irrigation and PSB application along with half of recommended dosage of chemical phosphorous fertilizer. Within all treatments application of PSB led to alleviate the negative impacts of irrigation halt.