JOURNAL OF CROPS IMPROVEMENT (JOURNAL OF AGRICULTURE)
Year:2012 | Volume:14 | Issue:2|Papers Count:7

In order to possibility of improving physiological traits, yield and yield components of safflower (Carthamus tinctorius cv. sina) by anti-transpiration application in rainfed condition, a research was carried out in factorial based on randomized complete block design (RCDB) with three replications in Miyaneh region (East Azarbaijan province-Iran) in 2011. The treatments antitranspirant rate were zero (control), 80, 120 and 160 g a.i.ha-1. The antitranspirant application time was at elongation, flowering and seed filling stages. The results showed that there were significant differences between treatments in all studied traits. Applying atrazine at 80 and 120 g a.i.ha-1 specially in flowering stage by providing plant favorite conditions such as reducing canopy temperature, increasing photosynthesis and chlorophyll content, improved yield and yield components comparing to rainfed stressed condition. Applying atrazine at 160 g a.i.ha-1 did not improve growth but acted as a growth inhibitor. The highest and lowest number of prolific capitol, number of seed in capitol and also grain yield were obtained at 120 g a.i.ha-1 in flowering time and 160 g a.i.ha-1 in elongation time, respectively.

In order to study the influence of nitrogen and different harvesting dates on sorghum yield, a split plot experiment based on randomized complete block design was conducted with three replications in 2010 at the Research Farm of Islamic Azad University, Ardabil branch. Factors were: different harvesting dates in three levels containing, beginning of flowering, two and four weeks after beginning of flowering and nitrogen fertilizer in four levels (zero, 60, 120 and 180 kg N.ha-1). The results showed that maximum of forage yield was obtained by the plots which were applied 180 kg N.ha-1 in four weeks after beginning flowering and the least of it was in no application of nitrogen fertilizer in beginning of flowering. Means comparison showed that the highest nitrogen use efficiency was obtained by the plots which was applied 60 kg N.ha-1 in four weeks after beginning flowering and the least of it was in application of 180 kg N.ha-1´beginninig of flowering. Maximum of stem and leaf protein was obtained in the highest of nitrogen fertilizer rates. It seems that in order to increasing of forage yield, should be applied 180 kg N.ha-1´four weeks after beginning flowering in climate conditions of Ardabil. If the aim is to improve nitrogen use efficiency, then applying 60 kg N.ha-1 in four weeks after beginning flowering can be suggested.

To investigate the effect of K fertilizer on yield and yield components of three watermelon cultivars, a two-year study (2007-2008) was conducted in Ardestan Agricultural Research Center (Isfahan province) by using of split plot randomized based on complete block design in three replications. Three watermelon cultivars (‘Sugar baby’, ‘Charleston Grey’ and ‘Mahbubi’), were assigned as main plots and four K fertilizer levels (zero, 50, 100, and 150 kg K.ha-1) were assigned as subplots. Two and three times higher than consumption of K fertilizer (100 and 150 kg K.ha-1) in compared to normal conditions (without salinity), led to a 24.8 and 18.5 percent increase in yield of ‘Charlston Gray’ and ‘Sugar Baby’, respectively. The highest fruit yield (39112 kg.ha-1), was obtained using 150 kg K.ha-1 in ‘Charleston Gray’ cultivar. Potassium applications at all levels, increased fruit number in ‘Sugar Baby’ and fruit weight in ‘Charleston Gray’, were considered as the main reason for increasing yield. By increasing of K application, the ratio of Na/K in the leaves from 0.61 to 0.33 and in the stems from 0.81 to 0.4 was decreased.The results indicated that in saline conditions, higher levels of K fertilizers can reduce the deleterious effects of salinity and thus may improve watermelon yield.

In this study, the amount of total phenol, chlorogenic acid, catechin, quercetin, phloridzin, cyanidin and antioxidant activity of apple (Malus domestica) skin and flesh of six Iranian cultivars, including: ‘Golab Kohanz’, ‘Sib Torsh Dirras’, ‘Ghara Yapragh’, ‘Torkman’, ‘Ghezel Alma’ and ‘Abbasi Mashhad’, and four commercial cultivars including: ‘Golden Delicious’, ‘Red Delicious’, ‘Braeburn’ and ‘Fuji’ was investigated. ‘Fuji’ had the highest amount of cyanidin 3-galactoside (3711.9 mg.g-1 fresh weight) and ‘Golab Kohanz’ had the greatest amount of quercetin 3-galactoside (3133.8 mg.g-1 fresh weight) and phloridzin in the skin (642.2 mg.g-1 fresh weight) and ‘Ghara Yapragh’ showed the greatest amount of flesh phloridzin (98.1 mg.g-1 fresh weight). ‘Abbasi Mashhad’ had the largest amount of flesh (484.3 mg.g-1 fresh weight) and the skin's (298.1 mg.g-1 fresh weight) chlorogenic acid, ‘Ghezel Alma’ had the greatest amount of catechin of skin (255.2 mg.g-1 fresh weight) and ‘Sib Torsh Dirras’ showed the highest catechin of flesh (76.9 mg.g-1 fresh weight). The regression analysis of total phenol and antioxidant capacity showed a positive correlation between the amount of total phenol and the antioxidant activity. The highest amount of total phenol and antioxidant activity in ‘Fuji’ was observed.

In order to investigate distribution status of heavy metals in cropping systems of water logging and dry farming, an experiment was conducted as split-plot arrangement based on randomized complete block design with three replications in research field of Sari Agricultural Science and Natural Resources University. A paddy-soil considered for water logging system and the planted field with vegetables considered for dry farming system. Main plot (fertilizer treatments added to soil) included five treatments: 20 and 40 ton.ha-1 compost, 20 and 40 ton.ha-1 sewage sludge and control. Also, sub factor (application years) consisted three treatments comprised: one, two and three years fertilization. The results showed that in water logging system sewage sludge treatments had more influence on heavy metals accumulation in soil while, compost treatments had more influence than sewage sludge treatments in dry farming system. Also, in paddy soil the enhancement percent of available form compared to control treatment was much more than dry farming system.

Fruit browning and tissue softening due to damages during handling, quality losses and water loss are the major limiting factors reducing postharvest life of early ripening apples. In this study, the effect of salicylic acid (SA) on fruit quality of apple cv ‘Golabe-Kohanz’ during postharvest life were investigated. Harvested fruits were immersed in zero, one, two and four mM SA and were maintained for 43 days at zero oC. SA decreased the soluble solids content at last stages of storage.In addition, SA reduced softening rate and water loss. At the end of storage, the highest firmness was observed in one and two mM SA treated fruits and the highest water loss was measured in control. Treatment of fruits by all three concentrations of SA showed a little browning. The highest browning was observed in those of control. Also SA delayed reduction of the total phenolic. The results demonstrate that SA postharvest treatment of apple cv., Golabe-Kohanz, through reducing browning and maintaining fruit quality increased postharvest life.

In order to study the effects of seed-bacterial priming (inoculation) on germination and early growth of alfalfa under salinity stress conditions, an experiment was conducted at seed research laboratory and Greenhouse of College of Agriculture, University of Tehran in Karaj (Iran) in 2011.The experiment was arranged as a factorial in Completely Randomized Design (CRD) with three replications. Experimental treatments including: three levels of salinity stress (zero (S0), 60 (S1) and 120 (S2) mmol), two levels of alfalfa cultivars (‘Bami’ and ‘Yazdi’) and 16 levels of bacterial priming (Azetobacter, Azospirillum, Pseudomonas and Rhizobium meliloti in single and different double, triple and quadratic integrated forms). The results indicated that applying salinity stress significantly decreased germination and early seedling growth. This descending trend in control (no inoculation) treatment was more than that of treated seeds. Application of bacterial priming especially Pseudomonas priming and integrated treatments played an important role in moderating the negative effects of salinity on measured traits. According to the results of this study, it seems that plant growth promoting bacteria, by producing and releasing phytohormones such as auxin, gibberellins and cytokinin along with decreasing ethylene level, improve plant growth under salinity stress condition.