mehrangiz jokar

This research was conducted in order to investigate some quantitative and qualitative traits of milk thistle under the influence of delayed planting dates in 2016 at the research farm of University of Jiroft. The experiment was carried out in the form of split plots in the form of a randomized complete block design in three replications. The main factor in this experiment was six planting dates (November 10, December 10, January 10, Bahman 30, March 10, April 10) and the secondary factor was three ecotypes of thistle (Kashan, Sari, Malathani). The measured traits included number of Capitulum per plant, number of seed per Capitulum, Weight of 1000 Seeds, plant height, seed yield and grain oil content (%). The results showed that the effects of planting date, ecotype and their interaction on all studied traits were significant (P<0.01). Under the influence of the delay in planting, all studied traits decreased linearly and significantly (P<0.01, R2>0.85). Based on these results, the decreasing slope under the influence of delayed cultivation was different in the examined ecotypes, so that the highest and lowest absolute values of the decreasing slope were observed in Malathani and Kashan ecotypes, respectively. The results illustrated that for every 10 days of delay in planting, seed yield decreased in Malathani, Sari and Kashan ecotypes by 251.4, 239.1 and 134.6 kg per hectare, respectively. The oil percentage decreased by 0.62 and 0.31, and 0.58 percent respectively. In general, in the subtropical conditions of Jiroft, the optimal planting date is November. The comparison between ecotypes also showed that although Mulathani and Sari demonstrated the highest yield of seeds and oil on the first planting date, Sari ecotype had more yield stability during the different planting dates.

Crop Simulation Models are advanced tools to estimate crop yield and optimizing of crop management practices. This study was conducted in order to evaluate DSSAT model under autumn cropping system condition in Jiroft, Iran, 2012 - 2014. The field experiment which repeated in two sequential years and three replications was performed with randomized complete block design in split plot. The main factor was planting date (17th, 23th, 29th September and 5th October) and its sub factor was potato cultivars (Sante, Satina and Boren). Data of first and second years of field experiment was applied respectively for calibration and evaluation of model. Data-base requirement for model was created from 1-climatic data includes: temperature, radiation, relative humidity, wind and precipitation, 2-crop data attained from field experiment, 3-soil data. Results of statistical evaluation of model showed the good fitness of yield simulated value and its actual value. In most cases, simulated tuber yield were similar to observed tuber production with a root mean square of 19% (1210 kg/ha). The R square index showed high correlation between observed and simulated value (Rsqr > 0.9). Simulated biomass had 2673.5 kg/ha difference to its observed value that was low precision estimation (RMSE > 30%). This model couldn’t predict tuber initiation stage correctly (RMSE > 30%). It was concluded however DSSAT model predicted potato yield but because of low precision in simulation of phonological stage and biomass value could not be used in autumn cropping system of potato.

In order to evaluate cyperus rotundus resistance to heavy metals stress, copper, nickel and cobalt, in the germination stage, the experiment was conducted in factorial based on completely randomized design with three replications in agronomy and horticulture laboratory of Jiroft University. The first factor consists of three metal copper, nickel, cobalt and the second factor levels consists of metal concentrations (0, 200, 400, 600, 800, 1000 ppm), respectively. The results showed that germination percentage, rate and mean germination time were affected significantly (p <0.01) affected by heavy metals and levels of stress and only, germination percentage were affected by their interactions. The effect of stress levels showed that treatments of 200, 400, 600, 800 and 1000 ppm, compared to control the tubers germination rate decreased tubers 17.8%, 26.07%, 35.7%, 46.4% and 57.1%, respectively. These treatments decreased tubers germination percentage respectively 9.2%, 14.9%, 24.1%, 36.7% and 45.9% compared to the control. The lowest germination percentage (70.5) and rate (1.7) happened in nickel stress. The Regression analysis results showed that germination rate changes affect the stress levels of copper, nickel and cobalt fit on quadratic function with R- square (R2) above 90%, which was statistically significant at 0.01. In general, the results of this experiment showed cyperus rotundus is tolerance to heavy metals stress so that, even able to germination and growth at concentrations up to 1000 mg/L, also tolerance Capability cyperus rotundus to copper heavy metal was higher than cobalt and nickel i.e. Cu >Co >Ni.