JOURNAL OF CROP PRODUCTION RESEARCH (ENVIRONMENTAL STRESSES IN PLANT SCIENCES)
Year:2014 | Volume:6 | Issue:3|Papers Count:6

In order to investigate the effect of different phosphorus levels on corn growth characteristics in saline soils of Ardabil region, an experiment was conducted with 10 levels of salinity (0.75, 1.2, 2.29, 3.3, 4.25, 5.11, 6.19, 8.8, 10.88, 14 dS.m-1) and 5 levels of phosphorus (0, 50, 100, 200, 400 kg.ha-1) in 3 replicates under greenhouse conditions as a factorial based on randomized complete blocks design. Initial soil samples were collected from 45 different points of Zaranas basin in Ardabil region. After determination of soil properties, 10 soil samples with different salinity levels were selected for the experiment. Phosphorus was supplied as di-ammonium phosphate source. The result showed that the plant height, leaf chlorophyll index and fresh and dry weight of shoot and root were increased with increment of phosphorus levels but decreased with the elevation of salinity levels. The combined effect of salinity and phosphorous on chlorophyll index and dry and fresh weight of shoot and root were significant at one percent level of probability but their effects on plant height were not significant. Application of phosphorus fertilizer decreased the negative influences of salinity and increased the corn growth by improvement of plant’s nutritional status.

In this research a total of 352 local wheat accessions of National Plant Gene-Bank of Iran were evaluated in salt stress condition. The accessions were received from 24 countries and were studied in research field of Ardakan station in Yazd province, Iran with soil EC of 10 ds/m. The seeds of the accessions were planted in an augmented statistical design with three check cultivars of Kavir, Yazd and Mahooti and irrigated by EC=12 ds/m water. Twelve agro morphological traits were recorded according to IPGRI descriptor. The result showed that the highest coefficient of variation (31.27) belonged to number of tillers. Five traits as independent variables including number of seeds per spikes, 100-seed weight, number of florlets per spikelets, number of stem nodes and plant height entered the stepwise regression model and justified 98% of variation in seed weight of five spikes. Based on favorable values of principal components and comparison with check cultivars, 14 accessions were identified as superior. The relationship among the origin of the accessions was investigated by cluster analysis and the countries were located in two groups. The total results of this research indicated the existence of suitable genetic diversity in the studied traits. Besides, bread wheat germplasm of National Plant Gene Bank of Iran proved to be a rich genetic resource to be exploited for salt tolerance.

In order to investigate the effects of silicon of application and nitrogen rates on yield and yield components of rice in two irrigation systems. Field experiment was conducted as split-split plot laid out in a randomized complete blocks design with four replications in Sari, during 2007. Three factors; irrigation system in two levels (Continuous flooding and alternative irrigation system) as main plots and nitrogen rates in four levels (N0, N46, N92, and N138 kg ha-1) as sub plots and silicon application in two levels (Si0 and Si500 Kg ha-1) as sub-sub plots. The results showed that flooding irrigation had increase biological yield, straw nitrogen content and 1000 grain weight. With deficit irrigation number of tiller per hill and harvest index had increased. The most plant height, number of tiller per hill, number of panicle per m2, number of total spikelet per hill, number of filled spikelet per hill, as grain yield, Straw and biological yield and the maximum grain and straw nitrogen content were obtained in N138. The maximum grain yield, straw yield, and biological yield were produced with Si500. The most straw nitrogen content was obtained in Si0. Interaction of N × Si only effect on straw yield and grain nitrogen content in 5% probability level. Therefore, silicon application decreased negative effect of irrigation and higher nitrogen application on rice plant.

In order to study the effect of some physiological traits and yield of basil (Ocimum basilicum L.) under different planting dates and potassium fertilizer amounts, an experiment was carried out as factorial based on completely randomized blocks design with three replications.Potash fertilizer was in 4 levels (40, 60, 80 and100 Kg per hectare) and sowing date included 2 levels (25th April and 20th May). The traits included, leaf dry weight, stem dry weight, leaf dry weight and biological yield per unit area at 2 harvesting was evaluated. Based on the results, the impact of applying potassium fertilizer on yield, leaf dry weight, stem dry weight, leaf dry weight per unit area of biological yield at 1% probability level in the first and second harvest were significant. Also, single effect of sowing date on leaf dry weight, stem dry weight, leaf dry weight per unit area and biological yield were significant at 1% probability level. The mean comparison results demonstrated that 60, 80 and100 Kg /ha Potash fertilizer increased the yield 6%, 16% and 28% compaired with 40 Kg /ha in first harvesting time and 7%, 9% and 19% at second  harvesting time alternatively.

In order to evaluate the effects of methanol on yield and some quality characteristic of sugar beet (Beta vulgaris L.) in drought and non-drought stress conditions, a study was conducted in 2013 at maahdasht (Karaj, Iran). In this research, Irrigation factor in 3 levels: normal irrigation (Irrigation after 40% depletion of available water), moderate drought stress (Irrigation after 60% depletion of available water) and severe drought stress (Irrigation after 70% depletion of available water) as main factor and methanol foliar application in 4 levels: 0(control), 7, 14, 21 and 28 (v/v) as sub factor were considered. The results indicated that there was significant difference between effects of solutions on extraction coefficient of sugar, white sugar content, nitrogen and water use efficiency. There was also significant difference between three levels of irrigations on extraction coefficient of sugar, dry weight of root, sugar content, white sugar content, molasses, water use efficiency and chlorophyll content. Interaction effects had significant difference for root yield and white sugar yield. The treatments 21% v/v and normal irrigation (Irrigation after 40% depletion of available water) and7% v/v and moderate drought stress (Irrigation after 60% depletion of available water) produced the highest root yield and located in the same statistical group.

In order to evaluate and classify morphological and physiological traits of wheat genotypes in non-drought and drought stress conditions, 30 wheat genotypes were planted based on completely randomized blocks desighn with six replications at the Research Station of Agricultural Faculty of Islamic Azad University of Tabriz during the agronomic year of 2012-2013. Three replications were considered as non-drought and three as drought stress conditions. The coefficients of grain yield in non-drought stress situation demonstrated positive significant correlation with the number of grains per spike, straw yield, harvest index, peduncle length, days to physiological maturity, biological yield, number of fertile spikelets per spike, spike length, plant height and in drought stress conditions, coefficients of grain yield showed positive significant correlation with straw yield, harvest index, biological yield. Factor analysis based on principal component analysis method and varimax rotation indicated that four important factors accounted for about 80.9 and 81.3 percent of the total variation among traits in non-drought and drought stress conditions, respectively. In non-drought stress conditions, the first factor assigned 22.1 percent of total variation between traits and was significantly related with grain yield. Therefore, this factor was regarded as yield factor. Other factors in non-drought stress condition accounted for 21.6, 20.9 and 16.2 percent of variation between traits and were entitled as grain yield component factors, respectively. In drought stress condition, the first factor assigned 23.3 percent of total variation between traits and was significantly related with traits spike length, number of fertile spikelets per spike and number of grains per spike. This factor was regarded as grain yield component factor. Other factors in drought stress condition accounted for 22.4, 22.1 and 13.3 percent of variation between traits and were entitled as height, yield and plant phenology factors, respectively. Overall, results revealed all traits had positive significant correlation with grain yield.