Crop Production
Year:2012 | Volume:5 | Issue:1|Papers Count:10

In order to study the effects of CO2 enrichment on growth and competitiveness of soybean (Glycine max) and millet (Panicum miliaceum) against redroot pigweed (Amaranthus retroflexus) and lambsquarter (Chenopodium albam) an experiment was conducted using two CO2 concentrations (350 and 700 ppm). For evaluating effects of CO2 variation on inter-and intra-specific competition plants were grown in monoculture and intercropping in greenhouse as factorial experiment based on the completely randomized design. The results indicated that with increasing CO2, chlorophyll index increased in all species but in average higher increase observed in C3 plants in mixture (20% increase) compare to C4 plants (12% increase). By increasing CO2 concentration root weight, leaf weight and stem weight in C3 species increased 0.75, 2.61 and 2.43 g respectively while, in C4 species these values were 0.04, 1.18 and 0.40 g respectively. Shoot dry weight of C4 species decreased in competition with C3 in high CO2 concentration. Comparison of plants PRY indicated that by increasing CO2 concentration soybean PRY increased by 8.9 and 9.6 against millet and pigweed respectively while, millet PRY decreased against C3 plants. This means that competition interaction of crop-weed could be affected by variation of CO2 in environment.

In order to study the effect of foliar application of zinc and iron on germination of soybaen seed under different level of irrigation, an experiment was conducted in 2009 at Shahrekord agricultural research center. Main factor was including of four levels of drought stress as irrigation (irrigation after 60, 80, 100 and 120 mm evaporation from class A evaporation basin) and sub factor was including of four levels of foliar applications (water, zinc sulfate, iron sulfate and combined of zinc and iron sulfate). Results showed that seed yield, seed zinc content, germination percent and rate and mean germination time and seedling and cotyledon dry weight were affected by the interaction of irrigation and foliar application. Irrigation after more eveporation significantly decreased 1000-seed weight. Foliar application of iron and combined of zinc and iron had significant effect on seed iron content. Germination percent in irrigation after 80 and 120 mm evaporation from the class A evaporation basin was not affected by foliar application, and iron foliar application in other levels of irrigation, let to the lowest germination percent. Foliar application of iron had the highest mean germination time. Foliar application of element. Root and shoot dry weight was increased by foliar application of zinc compared to water and combined of zinc and iron foliar application. Generally foliar application of zinc and combined zinc and iron, could improve most of the germination characteristics. High correlation coeficient between 1000-seed weight and seed zinc content with most of the germination characteristics, showed that these traits had maximum effect on germination of soybean.

In order to investigate the effects of different levels of nitrogen, phosphorus and potassium on quantitative and qualitative characteristics of flax oil, an experiment was conducted in 2009 in agricultural research farm of Aboureihan, Tehran University. The experimental design was randomize complete block with factorial arrangement in three replications. Factors in this experiment were different levels of nitrogen fertilizer (N1=30, N2=60, N3=90 Kg.ha-1), different levels of phosphorus (P1=40, P2=80, P3=120 Kg.ha-1) and levels of potassium (K1=40, K2=80, K3=120 Kg.ha-1), respectively. Results showed that respectively 90, 120, 80 kg.ha-1 of nitrogen, phosphorus and potash, increased significantly in branch number, capsule number, seed yield and oil yield. Obtained results of mean comparison showed that grain yield and oil, 2499.72 and 939.19 kg.ha-1, respectively. Maximum protein yield (1007.4 kg.ha-1) and its percentage (44.39%) obtained with consume 90 kg nitrogen, 40 kg phosphorus and 120 kg potassium per hectare. Results of analysis of variance the levels of fertilizer had not affected on oil percent.

To evaluate the effect of salinity on some quantitative and qualitative characteristics of spring rapeseed cultivars, an experiment was conducted in the greenhouse conditions at Yasouj University as a factorial with three replications. Four salinity levels (1.92 (as control), 9.87, 19.6 and 21.94 dSm-1 (NaCl and CaCl2 with ratio 20 to 1 in Hoagland solution)) as a first factor and eight cultivars as second factors were used. Some important quantitative and qualitative charecters of cultivars were recorded during growing season. Results showed that effect of salinity, cultivar and interaction between salinity and cultivar on studied characteristics were significant. Results showed that with increasing salinity levels, all measured traits, significantly decreased, except for number of non-fertile pod per plant. Generaly, Hyola60 and Hyola330 cultivars that showed higher amount of grain yield and oil yield than other cultivars were introduced as the most tolerant cultivars. Also these two cultivars had less non fertile pod at high salinity levels. PP-401-15E cultivar had a weak response to high salinity levels (19.6 and 21.94 dSm-1), and, it was introduced as the most sensitive cultivar to salinity.

In order to study effects of exogenous application salicylic acid on morphological and physiological characteristics of wheat (Shiraz cultivar) under soil and water salinity in the Neyriz city, an experiment was conducted in year 2009-2010 by factorial exprement in a completely randomized blocks design with four replications. Treatment consisted of three levels of priming with salicylic acid (0‚ 0.5 and 1 mMl-1) and spraying with four levels (0‚ 0.25‚ 0.5 and 1 mMl-1) at tillering stage. The results showed that salicylic acid used as priming and sprayed improved leaf area‚ chlorophyll a and b‚ yield and yield components. The most efficient treatment was combined treatment of priming and spraying with level of 0.5 and 1 mMl-1 concentrations which resulted in 42.9, 9.67 and 21.7% increase in ear number, seed weight and grain yield, respectively in comparison to control treatment. The concentration 1 mMl-1 caused a reduction compared to 0.5 mMl-1. The results suggest that salicylic acid is effective in reducing symptoms of salinity and in similar soil and water conditions application of 0.5 mMl-1 as priming and spraying can be recommened for wheat production.

This study was conducted to evaluate the effect of sowing date on morphology, yield parameters, as well as oil percentage and fatty acids composition of castor bean. The experiment was carried out at research farm of Tarbiat Modares University, in randomized complete blocks design with three replications during 2010. Plants were grown at six sowing dates of 5th April, 20th April, 5th May, 20th May, 5th June and 20th June. The results showed that morphological traits and yield traits were influenced by sowing dates. The highest seed yield (1590.67 kg/h), oil yields (774.43 kg/g) were obtained at 5th April, and delay in sowing date, led to significant reduction in these traits. Fifteen fatty acids were detected in oil. Nevertheless, the highest amount of fatty acid belonged to Ricinoleic acid. Results showed that fatty acid composition of castor oil influenced by sowing date. Therefore, it can be concluded, that 15th April could be recommended as an appropriate sowing date in the studied location and similar climates for achieved high oil yield of castor bean.

This study was conducted to evaluate the genetically effective traits that related to drought tolernace using 14 bread wheat lines and cultivars where in previous experiment clusterd into two resistant and susceptible groups under non-stress and stress conditions using randomized complete block design replicated three times. The combined analysis based on north carolina design II for studied triats in F1 generation revealed that the genotypice effect of male parents in two conditions, drought and irrigated, was significant for all traits with the exception of grain yield components including number of grain per spike and plant. The general combining ability (GCA) effects of cultivars were changed with decreasing of water availability. For most of the traits, the GCA × environment effect was significant. The estimates of narrow-sense heritability in two different moisture treatments revealed greater estimates for non stress than drought stress conditions due to genotype × environment interactions. The results revealed that for effectiveness of breeding program in drought stress, selection can be made under both full irrigated and water stress conditions. Harvest Index be suggested as powerful trait for screening of genotypes for drought stress tolerance.

In order to agroecological zoning of current agricultural lands in Golestan province for canola cultivation, Geographic Information System (GIS) and Analytical Hierarchy Process (AHP) were used to match the environmental requirements of crop and the land characteristics. The first, agroecological requirements of canola was identify from scientific resources then classified and needed thematic maps were provided. The classification of layers carried out by simple limitation approach. The digital environmental layers overlaid and integration in GIS media then zoning of lands was done in 4 classes of high suitable until non-suitable. The results showed that 21.31 and 35.04% of the area were high suitable and suitable for canola crop, respectively. These zones had enough rainfall (400-500 mm) and high fertility. The less suitable and non-suitable regions are located in the north and northeast parts of Golestan province. In these areas, the limitation factors were including: high EC, low precipitation, deficient nutrition elements and low water resources.

To evaluate the effect of growth promoting bacteria on morphophysiologic traits and nutrient uptakes of two rice cultivars, an experiment was carried out in 2009-2010 cropping season in Rice Researches Institute of Rasht. The experiment design consisted of four randomized complete blocks in a factorial arrangement having 16 treatments in 4 replications. In this research, two factors were evaluated: rice cultivars (Khazar and Hashemi) and eight levels of seed inoculation with PGPB and without seed inoculation. In this experiment, effect of both cultivar and effect of bacteria were significant on the most of studied characteristics. In this experiment, Khazar had positive effect on the most of studied characteristics in comparison with Hashemi. Application of these microorganisms increased the content of N, P, K, Ca and Fe in plant, but didn’t influence Mg adsorption. Between bacterial different strains, seed inoculation with 168, 177 and 93 strains increased evaluated characteristics significantly, compared with other strains.

In order to determine the appropriate amounts of potassium and nitrogen fertilizers to achieve high grain and oil yields of rapeseed (Hyola 401) in paddy fields, a field experiment was conducted at Rice Research Institute of Iran (Rasht) in a factorial experiment based on the complete randomized block design with 3 replications in 2008-2010. The first factor was the amounts of potassium fertilizer in three levels (100, 150 and 200 kg.ha-1) and the second factor was nitrogen fertilizer values in the four levels (zero, 180, 240 and 300 kg.ha-1 from urea resource). The results of the combined analysis of variance showed that significant difference between potassium levels, according as application of 150 and 200 kg.ha-1 potassium had the highest of grain yield. Between the levels of nitrogen, application of 240 and 300 kg.ha-1 produced the highest grain yield. The control treatment with average of 43.92%, showed the maximum oil precent. In general, 150 kg.ha-1 of potassium and 240 kg.ha-1 nitrogen level are recomended due to less fertilizer consumption and prevention of destroying effect on the environment.