CROP PHYSIOLOGY
Year:2013 | Volume:4 | Issue:16|Papers Count:11

In many areas of country, rapeseed yield and yield components are exposed to water stress. In order to investigate water stress effect on quantity and quality characteristics of rapeseed cultivars, a research was conducted in split-plot design on randomized complete block design with four replications at the research field of Pardis Abouraihan-Tehran in 2007/8 cropping year. In this experiment, two spring rapeseed (Brassica napus L.) cultivars including RGS003 and OPTION500 as main plot and irrigation treatment in three interval as sub plot (once in 6, 8 and 10 days) were studied. Net irrigation depth, intervals between irrigations and the amount of water at every turn which was given to the ground were calculated by using related equations. The results indicated that the highest seed yield, biological yield, oil yield, plant height, silique number and silique length in plant was obtained in RGS003 cultivar with 6 irrigations periods. The highest 1000-seeds weight, harvest index, oil percentage and stem dry weight (STM) was observed in OPTION500 cultivar with 6 irrigation periods. Also, the highest plant hollowness percent was related to OPTION500 cultivar with 10 irrigation periods.

In order to study the effects of osmopriming on germination and yield of different cultivars of mung bean (Parto, Gohar, Indian) a research was done at farm and laboratory of Safi-Abad Dezful Agriculture Research Center in the summer of 2010. This experiment was done in two steps: laboratory and in a farm. In the laboratory phase, two separated tests was done in two exhausted and non-exhausted environments in the case of combined analysis. In each environment, factorial test was consisted of three cultivars of mung bean (Parto, Gohar and Indian) and different levels of potential osmosis (0, -3, -6 and -9 bar) which was carried out with 3 replications. The farm phase was a factorial experiment with three factors and conducted as a randomized complete block design with 3 replications, the first factor consisted (Parto, Gohar and Indian) cultivar, the second factor was exhaustion (by using of exhausted and non-exhausted seeds) and the third factor consisted of different levels of potential osmosis (0, -3, -6 and -9 bar). The results indicated that cultivar, priming and exhaustion stress treatments on all studied characters in lab and field had a meaningful effect.

In order to investigate the effects of different amounts of iron and sulfur fertilizers on some quantitative characters of sesame under drought stress conditions, an experiment was carried out as a split factorial design in randomized complete blocks with three replications during summer 2010 at city of Gotvand. Treatments consisted of drought stress as main factor at two levels (control and stress in flowering stage) and fertilizer treatment as sub-factor consisted of: iron in three levels (0 (control), 3 and 6 per 1000 from iron solution) and sulfur at three levels (0, 200 and 500 kg/ha from bentonite sulphurin). The results of this experiment showed that drought stress in flowering stage had no significant effect on grain yield but among the grain yield components, drought had significant effect on pod number per bush and sub branch number and decreased them. Iron and sulfur had not meaningful effect on grain yield and yield components separately. In this experiment the highest grain yield was obtained during using iron and sulfur fertilizers in 200 kg sulfur fertilizer treatment and 3 per 1000 iron spraying.

In order to evaluate the effect of two Nicosulfuron and Foramsulfuron herbicides in comparison with common corn herbicides an experiment was conducted during 2010 cropping year in Shoushtar. This experiment designed as a randomized complete block with four replications. Experimental treatments were consisted of Foramsulfuron 1.5 lit ha-1, Foramsulfuron 2.5 lit ha-1, Nicosulfuron 1.5 lit ha-1, Nicosulfuron 2 lit ha-1, Atrazin 1 lit ha-1+Lasso 4 kg ha-1 and control plot with no control. Results indicated that the effect of herbicide treatments on weed number and dry weight was significant in 1% probability level. The lowest weed population and the dry weight and also the highest weed control efficiency (WCE) was belonged to Nicosulfuron 2 lit ha-1. The difference between this treatment and Foramsulfuron 2.5 lit ha-1 treatment was not significant as regards to weed number. Nicosulfuron 2 lit ha-1 herbicide efficiency in weed control was higher than other treatments especially the combination of Atrazin and Lasso herbicides. Nicosulfuron 2 lit ha-1 herbicide controlled, narrow leaf soruf weed, Oyarsalam and also broad leaf pursalane weed with high efficiency. The highest grain yield on corn was belonged to this treatment that had meaningful difference with other treatments. Higher grain yield in Nicosulfuron 2 lit ha-1 treatment was due to increasing grain number per ear and 1000-grain weight.

In order to investigate the effect of different irrigation regimes on growth, yield and yield components of grain sorghum cultivars, this experiment was conducted as a split plot in randomized complete block design with three replications in research farm of Agriculture and Natural Resources Research Center of Yazd during the summer of 2011. Main plots were included 3 irrigation regimes I1, I2 and I3 (irrigation after 7, 10 and 13 days) and sub-treatment consisted of 3 grain sorghum cultivars Payam, Sepideh and Kimia. Sowing was done with hand on 26 June. Distance between rows and distance on rows were considered 60 and 10 cm, respectively. Different traits were measured and recorded during growth stage and harvest time. Results indicated that increasing irrigation intervals from I1 to I3 treatment reduced length of cultivars growth period, panicle length, number of panicles in plant, number of kernel in panicle, 1000-kernel weight and grain yield of sorghum cultivars significantly. As grain yield in I2 and I3 was reduced to the amount of 10.5% and 30%. There was a significant difference between grain yield and yield components of cultivars. Sepideh cultivar had the maximum panicle length and number of kernel in panicle. Grain yield from the highest to lowest amount was belonged to Sepideh, Payam and Kimia cultivars, respectively. As drought stress reduced yield of Payam cultivar (57% reduction in I3) more than other cultivars, Sepideh cultivar had the minimum yield reduction amount (37 percent) and Kimia cultivar had a yield reduction to 44 percent.

This experiment was conducted in 2009-10 cropping year in order to investigate the effects of previous crops and planting pattern on weeds and wheat yield reduction at Shams-Abad village of Dezful. The experimental design was a randomized complete block with split plot arrangement with four replications. Main treatments (previous crops) consisting: mung bean (P1), clover (P2) and fallow (P3) and sub treatments (Planting pattern) consisting: two rows on 60cm spaced furrows (A1), three rows on 75cm spaced furrows (A2) and four rows on 95cm spaced furrows (A3). Results based on variance analysis showed that planting pattern treatments had significant effect on weeds dry weight in two stages of bolting and heading of wheat, grain yield, spike number in m2, grain number in spike and 1000-kernel weight traits. Also, previous crops treatments had significant effect on weeds dry weight traits in three stages of bolting, heading and physiological maturness of wheat, grain yield, spike number in m-2 and grain number in spike. Interaction of planting pattern and previous crops had significant effect on traits: weeds dry weight in heading stage of wheat, spike number in m2 and kernel number in spike. Totally, results indicated that previous crop mung bean (P1) with four rows on 95cm spaced furrows (A3) had significantly controlled weeds and increased grain yield in wheat.

In order to study the quantitative and qualitative traits of hay in flowering stage of forage vetch, under effect of different densities, an experiment was conducted at research field of Faculty of Agriculture, Lorestan University in autumn 2007. The experiment was carried out as factorial based on a randomized complete block design with three replications. In this experiment three species of vetch including (broad leaf, common and woolly pod) were studied and evaluated under three plant densities (100, 150 and 200 plant m-2). Interaction (density in species) showed the highest hay yield with 2268 kg ha-1 was produced in 200 plant m-2 by broad leaf vetch and the lowest hay yield with 724 kg ha-1 in 100 plant m-2 by woolly pod vetch. Moreover, species and density had significant effects on qualitative traits of hay (crude protein percent and yield), percentage and yield of insoluble fiber yield in neutral detergents and (density×species) interaction as well. In this experiment plant height was under the effect of (density×species), as well as stem diameter under the effect of species.

In order to investigate the effect of different levels of salinity stress on Anions and Cations absorption concentration in different lines and cultivars of rapeseed (Brassica napus L.), a factorial experiment in completely randomized design with three replications was carried out at research greenhouse in Agricultural Research center of Mazandaran in 2009-2010 cropping year. Four levels of water salinity including (0 (control), 4, 8 and 12 ds/m-1) were considered as the first factor and seven cultivars including (Zarfam, Sarigol, Line 14 Line 18, Line 111, RG003 and Hayola 401) as the second factor. The results showed the most absorption concentrations of Mg, Ca and Na was obtained for RG003 cultivars and Line 14, respectively and also the highest amount of K and Cl absorption concentrations were belonged to RG003, Zarfam and Sarigol cultivars in vegetative stage. As the highest amount of Line 14 and RG003 cultivars was obtained in Ca and Na concentrations, the highest amount of Na, K and Cl were related to Line 111, Sarigol, Zarfam and RG003, respectively at reproductive stage. In addition, due to increasing salinity stress in elements concentration in comparison with vegetative stage had less variation, as in generative stage, absorption concentration of Na and Cl elements were about eight and two times of their amounts in comparison with control treatments, respectively.