مهتا حق جو

high germination rate and vigorous early growth under salty soils is preferred. In this study germination and seedling growth of a canola (Brassica napus L.) cultivar (Hayola 401) was assessed using in a factorial laid out in three separate experiments as Completely Randomized Design (CRD) testing combinations of four levels of salinity (0, 80, 160 and 240 mMol NaCl) and three levels of salicylic acid (0, 0.5 and 1 m gr Lit) in the first experiment, the same salinity levels with four levels of gibberellic acid (0,1.5, 3 and 4.5 m Mol) in the second experiment and the same salinity levels with four levels of abscisic acid (0, 2, 4 and 6 m Mol Lit) in the third experiment. Results showed that germination percentage and germination rate was significantly increased by salicylic acid (SA) and gibberellic acid (GA) under salinity conditions compared to non-treatment of these two hormones. Priming with SA could not improve radicle length and radicle dry weight in all salinity levels. Application of GA enhanced radicle and hypocotyl length in all salinity levels compared to untreated seeds with treatment. ABA decreased germination percentage to about 12 % in 2 m Mol than control. Priming with ABA could not improve radicle length in all salinity levels. Seeds primed with ABA improved dry weight of seedlings as compared to non-treatment of ABA under non salinity and salinity conditions. In general, tolerance to salinity in canola seed increased with SA, GA and ABA compared to control.

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.

DSSAT-CMS computer model simulates growth, development and crop production under the management conditions such as variation in soil moisture, soil carbon, soil nitrogen and nitrogen leaching. In this study, first CERES-Maize model with 20% moisture depletion and then grain yield and biomass of corn at harvesting time were calibrated. Calibration coefficients for corn single cross 260 were P1=169, P2=0.386, P5750, G2=775.9, G3=8.82 and PHINT39.20. Results showed that the model estimates grain yield and biomass in normalized mean root of error squares (RMSEn), Wilmot agreement index (d) and correlation (R2) coefficient at 18, 90 and 82 percent and 29, 84 and 84 percent respectively. Therefore, CERES-Maize model has the high precision in simulation of these two traits and also simulation was desirable in Shiraz region. The model simulated grain yield better than biomass. In general, the model can be used for irrigation and nitrogen management in the region.