Iranian Journal of Crop Sciences
Year:2016 | Volume:17 | Issue:4|Papers Count:7

To study the effect of phosphorus levels (0, 40, 80 and 120 kg.ha-1) and parboiling of paddy on phytic acid and mineral content of three rice varieties, a field experiment was carried out as factorial arrangements in randomized complete block design with three replications at Rice Research Institute, Rasht, Iran, in 2012.Results showed that soil phosphorus deficiency decreased grain yield. The highest grain yield was observed at phosphorus levels of 80 and 120 kg.ha-1 and the least yield was obtained in phosphorus levels of 0 and 40 kg.ha-1.Results also showed that by increasing the soils phosphorus levels, phytic acid content increased but decreased Fe and Zn contents and availability. The highest phytic acid content was observed in Khazar cultivar and phosphorus level 120 kg.ha-1 (16.82 mg.g-1). A reduction in the phytic acid content was observed after parboiling, showing over 80% reduction in 3 rice cultivars. Least phytic acid content was observed in Gohar cultivar and 0 kg.ha-1 phosphorous (1.67 mg.g-1). Parboiling also increased mineral contents such as phosphorus, Fe and Zn in parboiled milled rice. During parboiling process phytase enzyme activity increased and the highest phytase activity was observed in 80 kg.ha-1 phosphorus in all rice cultivars. Results revealed that increased phosphorus content enhanced phytic acid content and decreases phytase activity and mineral nutrition content.However, parboiling reduced phytic acid content. Reduction of phytic acid during parboiling can be attributed to the enzymatic hydrolysis taking place during soaking and steaming and the breakdown of the ring structure of phytic acid during heat treatment of parboiling.

To evaluate forage yield and quality of Persian clover lines, a field experiment was carried out using randomized complete block desigh with 15 lines and four replications in filed station of Seed and Plant Improvement Institute and nutrion labarotory of Animal Science Research Instiute of Iran, for two growing seasons (2009-11), Karaj, Iran. Combined analysis of variance showed significant diffrences among Persian clover lines for crude protein, digestable dry matter, organic matter digestability, dry matter organic matter digestability, AFD and NFD. Results showed that clover lines of higher quality belonged to Eqlid-e-Fars, Kordestan, Local Zabol, Hafte-e-chin Shazand and Baladeh-e-Kazeroon clover populations. Line No.1 with 31.8 t.ha-1 and 6.6 t.ha-1 had the highest fresh forage and dry forage yields, respectively. Mean comparison of cuts showed that the first cut with 47.6 t.ha-1 fresh forage and 9.6 t.ha-1 dry forage yield was superior to the second and third cuts. Mean comparison of years showed that forge production was higher in the first year by 9%. Overall results showed that lines No.1, 2, 3, 5, 6 and 8 were promising lines that can be used for animal feed.

To identify high yielding rapeseed lines with grain yield stablity under different moisture conditions, a field experiment was carried out consisting of 17 new rapeseed lines and two cultivars (Ahmadi and Opera). The genotypes were compared using randomized complete block design with three replications under three moisture conditions for two cropping seasons (2012-2013 and 2013-2014) at agricultural research station of Islamabad-e-Gharb, Kermanshah, Iran. Three irrigation regimes included; normal irrigation, no irrigation from flowering stage and no irrigation from silique stage. Considering significant year × genotype × irrigation regime interaction effect, some stability statistics was calculated for selection of high yielding lines with seed yield stability. Results showed that line L183 had the highest seed yield stability using different stability statistics. This line had 4129 kg.ha-1 seed yield. However, considering stability statistics such as superiority parameter and simultaneous selection methods for seed yield and stability, lines KS7 and KR4 with 4367 and 4346 kg.ha-1, respectively, were also identified as high yielding lines with seed yiled stability. New cultivar, Ahmadi, with 3600 kg.ha1 had the low environmental variance and coefficient of variation under different irrigation regimes, could be considered for being grown under terminal drought stress conditions.

This experiment was conducted using three synthetic cultivars and their seven parental populations at two different conditions including: non-stress and drought stress. The experiment was carried out using randomized complete block design with three replications at the Research Field of Aboureyhan Campus, University of Tehran, Iran, in 2013. Analysis of variance showed that there were significant differences between genotypes for all traits in two experiments. The highest seed yield in normal irrigation belonged to medium-maturity synthetic cultivar and Meshkinshahr with 2357 and 2208 kg.ha-1, respectively. However, in drought stress condition the highest seed yield obtained from Meshkinshahr and medium-maturity synthetic cultivar with 1091 and 1081.5 kg.ha-1, respectively. Genotypic correlations in non-stress condition between seed yield with umbel diameter (r=0.79**), number of umbels (r=0.94**), number of umbellate (r=0.89**) and number of seed umbel-1 (r=0.89**) were positive and highly significant. In drought stress condition condition also the genotypic correlation between seed yield with umbel diameter (r=0.96**), number of umbels (r=0.77**), number of umbellate (r=0.86**) and stem diameter (r=0.85**) were positive and highly significant. Results of stepwise regression analysis revealed that in non-stress conditions number of umbels, number of umbellate, number of seed umbel-1 and stem diameter, and in drought stress conditions number of umbels, stem diameter and number of nodes were identified as independent variables that explained variations in seed yield. Path analysis for seed yield also indicated that in both non-stress and drought stress conditions number of umbels had the highest direct positive effect. It is concluded that in normal and drought stress conditions, number of umbels is the most important trait for selection of fennel genotypes with high seed yield.

To determinate the optimum combination of barley with fenugreek in intercropping at different cow manure levels, a field experiment was carried out as split plot arrangements in randomized complete blocks design with three replications at research farm of Ramin Agriculture and Natural Resources University of Khouzestan, Iran in 2014-2015 growing season. Four manure levels including; 0, 12, 24 and 36 t.ha-1 were assigned to main plots and eight levels of replacing and addative ratios of intercropping including; 75% barley+25% fenugreek, 50% barley+50% fenugreek, 25% barley+75% fenugreek, 100% barley+16.6% fenugreek, 100% barley+33.3% fenugreek, 100% barley+50% fenugreek and pure stands of barley and fenugreek were randomized in sub-plots.Results showed that the highest dry matter yield (3166 kg.ha-1) obtained from 100% barley+50% fenugreek with 36 t.ha-1 of manure. The highest crude protein content and dry matter digestibility obtained in pure fenugreek with 36 t.ha-1 of manure. The highest levels of total carbohydrate obtained from pure barley with 24 t.ha-1 of manure. Results of this experiment showed that 100% barley+50% fenugreek with 36 t.ha-1 of manure produced the maximum dry forage yield and quality and the highest LER (1.180), therefore was identified as superior treatment.

Effects of salinity on morpho-physiological traits of twenty-five hexaploid wheat genotypes (landraces, commercial cultivars, promising breeding lines, and Arg, Bam, Ofogh and Sistan as checks), were studied. Bread wheat genotypes were evaluated in randomized complete block design with three replications in each of the environmental conditions (saline and non-saline conditions) at the research filed station of Birjand, Iran in 2012- 2014 cropping seasons. Combined analysis variance revealed significant differences among grnotypes for the studied traits. In saline condition, the maximum grain yield (5517, 5322, 5317 kg.ha-1) obtained in genotypes No.25, 22 and 20, respectively and in non saline condition the maximum grain yield (7869, 7728 and 7706 kg.ha-1) obtained in genotypes No.1 (Sistan), 20 an 25, respectively. Results showed salinity led to decreased K+/Na+ ratio of flag leaf, grain yield, biological yield, flag leaf area, length of penultimate, length of peduncle, plant height and increased Na+content of flag leaf and canopy temperature as compared with non-stress condintion. In saline condition, grain yield was significantly and positively correlated with grain yield in non-stress, biological yield (BY), K+/Na+ratio, chlorophyll content (SPAD), relative water content (RWC), harvest index (HI), length of spike, length of peduncle, thousand grain weight (TGW), while it was negatively correlated with Na+content of flag leaf. Stepwise regression analysis in saline condition showed BY, HI, K+/Na+ratio, Na+content of flag leaf, length of spike and width of flag leaf justified the majority of grain yield variation and can be used for indirect selection of grain yield. Factors analysis identified five factors which explained 80.46% of the total variation. On the basis of these results, it is concluded that criteria such as BY, HI, K+/Na+ratio, Na+content of flag leaf, length of spike, chlorophyll content, RWC and TGW could be considered as effective criteria for selecting to improve grain yield in the national wheat breeding programs for tolerance to salinity stress.Genotypes No.25, 22, 20, 21, 24, 13 and 23 were determined as more tolerant genotypes even more than check cultivars. These genotypes have salt tolerant parents shuch as: Karchia, Sakha8 and 1-66-22 in their pedigrees.

In this experiment the effect nitrogen fertilizer levels (0, 75, 150, 225, 300 and 375 kg.ha-1) and four irrigation levels (normal irrigation, irrigation withhold at spike emergenc, grain filling stages and rainfed conditons) were evaluated on grain yield and agronomic traits of wheat cv. Sirvan during 2013-2014 and 2014-2015 at College of Agriculture, Shiraz University, Iran. Results showed that agronomic nitrogen use efficiency (ANUE), water productivity (WP), grain yield and yield components were reduced and protein content of grain increased under rainfed conditions. Grain yield and biological yield under rainfed condition were lower than normal irrigation by 67% and 58% in first and 75% and 65% in second years, respectively. The maximum grain yield and biological yield were obtained in 150 and 225 kgN.ha-1, under normal irrigation condition (5681 and 11950 kg.ha-1 for the first and 4545 and 10158 kg.ha-1 for the second years, respctivley). Irrigation withhold at spike emergence and grain filling stages were associated with reduction in 1000 grain weight, grain yield, biological yield and harvest index and increase in protein content of grain in both years. Nitrogen application up to optimum level (150 kg.ha-1) enhanced grain yield, yield components and water productivity in both years, but as water stress was intensified, the positive effect of nitrogen fertilizer was lowerd. The maximum water productivity was obtained in 150 kgN.ha-1 under irrigation withhold at spike emergence stage (815 and 672 kg.m-3 in first and second years, respectively). ANUE was reduced by increase in nitrogen fertilizer rate and the lowest rate was obtained in 375 kgN.ha-1. The maximum ANUE was obtained in 75 kgN.ha-1 under irrigation withhold at grain filling stage treatment (20.5 and 19 kg.kg-1 in the firast and second years, respectively). Overall, under normal irrigation condition, the application of 211.4 and 195.3 kgN.ha-1 and under rainfed condition, the application of 144.1 and 138.5 kgN.ha-1 (for the first and second years, respectively) were determined as the optimum rate of nitrogen fertilizer for wheat cv. Sirvan.