PLANT AND ECOSYSTEM
Year:2013 | Volume:9 | Issue:35-1 (SUPPLEMENT)|Papers Count:9

In an attempt to investigate the effects of the levels of deficit irrigation and wheat stubble management on the agronomical and morpho-physiological traits of mung bean (Vigna radiate L.), an experiment was carried out in split-plot following a randomized complete block design with three replications during 2009. The main factor comprised deficit irrigation at three levels: the interrupted irrigation at the onset of podding (I1), the interrupted irrigation at the onset of flowering (I2), and the common irrigation (I3). The subplots included wheat stubble management at three levels: planting in stubble by zero tillage (M1), planting in burned stubble by zero tillage (M2), and planting by traditional tillage. The results indicated that the aforementioned treatments had significant effect on grain yield, plant height, the number of secondary branches, dry matter, and harvest index. Grain yield, the number of secondary branches, stem diameter, plant height, dry matter, and harvest index were higher in common irrigation in comparison to the other irrigation levels. Grain yield, the number of secondary branches, dry matter, and harvest index were also higher in traditional tillage compared to M1 and M2 treatments. The Mean comparison of the interaction effect of irrigation and stubble managements revealed that the highest and the lowest grain yield were produced by common irrigation with traditional tillage and the interrupted irrigation at the onset of flowering with planting in stubble, respectively.

To investigate the effect of different times and concentrations of Zn-chelate fertilizer spraying on corn seed (704 cultivar), an experiment was carried out in split plot in Khatam region, using a randomized complete block design with three replications. The treatments included three spraying times (T1=spraying the plant with 5 to 8 leaves, T2=spraying the plant with 5 to 8 leaves at the emergence of crown flower, and T3=spraying the plant with 5 to 8 leaves at the emergence of crown flower at dough stage) in the main plot, and different concentrations of Zn-chelate (i.e. C1=zero application of Zn (control), C2=spraying 0.5 kg /ha Zn, and C3=spraying 1 kg/ha Zn) in the sub-plot. The traits under study included corn weight, the number of seeds and rows in corn, cob weight, corn length, 1000-grain weight, and seed yield. The results indicated that the aforementioned treatments had a significant effect on grain yield, the number of seeds, 1000-grain weight, and cob weight. On the contrary, corn length and weight and the number of rows were not affected. The interaction effect of the two treatments also revealed that the highest 1000-grain weight (373.3 g) obtained from 1 kg/ha Zn and T3 spraying treatments. The results indicated that spraying 1 kg/ha Zn significantly increased grain yield and the number of seeds in corn. The highest average of the number of corn seed and grain yield obtained from the third level of spraying time, i.e. spraying the plant with 5 to 8 leaves at the emergence of crown flower at dough stage. The highest grain yield belonged to 1 kg/ha Zn and T3 spraying treatments.

Given that uninformed exploitation and unstable management resulting from the changes in land use system in a number of almond orchards of Saman plain in Chahar mahal and Bakhtiari province are seriously threatening these resources, an experiment was carried out to evaluate the intensity of soil destruction in these regions. It aimed to investigate the effect of changing land use system on the organic carbon, the total nitrogen, and the microbial respiration of the soil. For so doing, three land use systems in Saman plain including a permanent almond orchard, a permanent pasture, and an almond orchard changed to an agricultural land were selected. Samples were gathered from regular networks (30 ´30 m) of topsoil (0-30 cm depth) in the farming year of 2010. The total nitrogen, the organic matter, and the microbial respiration of the soil were measured using standard procedures. Data were analyzed with the help of SPSS and Excel software, following a completely randomized design. The analysis of variance indicated that changing a garden ecosystem to an agricultural one had a significant effect on the organic carbon, the total nitrogen, and the microbial respiration of the soil indices at P<0.01. Furthermore, comparing these indices using Duncan method revealed that there was a significant difference at P<0.01 between the mean of the organic carbon, the total nitrogen, and the microbial respiration of the soil in all three land use systems. Changing a garden ecosystem into an agricultural one decreased 54, 62, and 40 percent of the organic carbon, the total nitrogen and the microbial respiration of the soil, respectively. Preserving pasture lands and replacing pasture plants increased the organic carbon, the total nitrogen, and soil microbial respiration, respectively, to 35, 45, and 30 percent compared to the agricultural ecosystems. There was a significant positive relationship between the organic carbon, the total nitrogen, and soil microbial respiration variables. The correlation analysis of variables using the Pearson test confirms a significant correlation between these three variables at P<0.01. Generally speaking, the microbial respiration, total organic carbon, and nitrogen indices were respectively the most reliable indicators of soil quality for the region under scrutiny. The average values of these indices can be introduced as optimum limits for selecting alternative managements and different tillage methods in the aforementioned land use systems.

For preserving the quality of fruit and consumer preferences as well as managing the market, it is necessary to keep them into cold storage. Pear is a sensitive fruit whose quality and physical features are largely influenced by storage environment. This experiment was carried out to investigate the effect of polyamines and salicylic acid on preserving quality, nutritional traits, and market preference of pears. Fruits were treated for 5 minutes with two types of polyamine (espermine and espermidine), each with concentrations of 1 and 1.5 milimolar, and the salicylic acid hormone, with concentrations of 4 and 8 milimolar, following the drowning method. They were then put into storage at 0.5 degrees centigrade and the relative humidity of 85%. Samples were taken 8, 18 and 20 weeks after storage and features such as tissue density, humidity, dry weight, vitamin C, TSS, TA, PH, and fruit rot were measured. The results indicated that the polyamine treatment preserved humidity in comparison to the fruits in the control group. During the storage period, fruits in the control group were more rotten compared to the other treatments. The salicylic acid and polyamines treatments were influential in keeping the firmness of fruits and preserving vitamin C.

Nitrogen fertilizers play a significant role in enhancing crop yield, shoot development, and metabolites production by increasing photosynthesis levels. The present study explores the effect of nitrogen on dry matter yield of a medicinal plant, i.e. lavender (Lavandula officinalis L.). For so doing, an experiment was carried out with four replications, following a randomized complete block design, in the research field of Islamic Azad University, Shahr-e Rey. Different traits such as dry and wet weights of shoot, dry weights of leaf and stem, plant height, stem diameter, and the number of branches were treated using six different treatments including: control, 60, 90, 120, 150, and 180 kg nitrogen per hectare as urea resource. The results indicated that different amounts of nitrogen significantly affected all of the traits. An increase in the amount of nitrogen per hectare resulted in an increase in the traits under study in a way that two of the treatments, i.e. 150 and 180 kg nitrogen per hectare, resulted in the highest dry and wet weights in shoot and dry weights of leaf and stem.

To investigate the role of leaves at different parts of sunflower stem (Helianthus annus L.) in yield and yield components, an experiment was carried out in Amiran village, Ardestan, in 2009. Three cultivars of sunflower (i.e. Alestar, Hyson, Iroflour) were analyzed in a split-plot study following a randomized complete block design. Five levels of defoliation treatments were conducted at the beginning of pollination on the basis of R5 and the effects of five treatments (control, one-third of the upper part of stem, one-third of the middle part of stem, one-third of the lower part of stem, and complete leaf removal) were analyzed. The percent of hollow grains per head, 1000-grain weight, grain yield and biomass, harvest index, the grain oil percentage, and oil yield were evaluated. The results indicated that there was a significant difference in the varieties under study reading harvest index (at P<0.01), biomass yield, and 1000-grain weight (at P<0.05). No significant effect was observed in the percent of hollow grains, oil, and oil yield. In addition, the interaction effect of sunflower varieties and leaf removal was only significant for the percent of hollow grain per head. The oil percentage was only affected by complete leaf removal treatment. Compared to the control treatment, the complete leaf removal resulted in the highest decrease of the traits under study. From among the traits discussed above, leaf removal of the middle-part of the stem demonstrated a higher decrease in comparison to the upper- and lower-stem leaf removal.

Saffron (Crocus sativus L.), widely recognized as red gold, is produced from dried stigmas of Crocus sativus L. plant. The cultivation and production of saffron have an ancient history in Iran. Over the past two decades, various experiments have been conducted on the cultivation of saffron in different regions of Iran including Karaj, Birjand, and Shahrekord. The best saffron corms in terms of yield and quality are found in Iranian saffron masses. Over 500 kg of the best saffron corms were used in order to investigate their growth and development possibilities. This study was done for the first time using the common method during 2009-2010, i.e. dry farming, in the research farm of Islamic Azad University in Shahr-e Rey. The experiment was carried out in split plot form, following a randomized complete block design, with tree replications. The treatments included four planting dates as the main factor and two cultivars (Ghaen and Esfahan) as the secondary factor. The yield, quality, and growth indices (Leaf Area Index, Total Dry Matter, Crop Growth Rate, and Net Assimilation Rate) of saffron were determined. The results indicated that the planting dates did not significantly influence any of yield traits. In addition, the results of mean comparisons revealed that Esfahan cultivar was better regarding all traits in comparison to Ghaen cultivar and thus demonstrated a better compatibility with Shahr-e Rey district. Accordingly, there is a possibility to grow saffron in Shahr-e Rey considering its limited water consumption and the economic justification.

The relative concentration of zinc, copper, and calcium in the seed of different parts of spike were evaluated in an attempt to select the best seeds in wheat spike (Triticum aestivum L. var. PBW-343). The spikelets in the main spike were divided into proximal, middle, and distal regions. The grains in each spikelet were divided into basal and apical parts. The concentrations of zinc, copper, and calcium were at the lowest level in the 14th day. Seeds in the basal part of the middle region spikelet were in a higher level in comparison to the grains of the other parts. The basal seeds in the distal spikelet had a higher concentration of calcium compared to the other parts.

In Iran, soybean (Glycin max L.) is usually grown in Golestan and Mazandaran provinces due to its special ecological demands. About 60,000 to 70,000 hectares of the lands in Golestan province are used to cultivate this crop each year. Given that the identification of factors that improve the agronomic conditions can be influential in improving the production of this oil crop, a split-plot experiment including two factors and 12 treatments was carried out with four replications. It followed a randomized complete blocks design and was conducted in Ali Abad Katool region (Kamalan Zone) in 2010. The main factor included the planting date at six levels (2th, 12st, and 22nd of July and 1st, 11th, and 21st of August) and the second factor included nitrogen fertilizer at 2 levels (0 and 25 kg/ha pure nitrogen). The results indicated that the number of healthy pods in the whole plant, the main stem, and the secondary branch was influenced by the planting date. The 2nd of July was the best planting date in comparison to the other times due to the average grain yield amounting to 3941 kg per hectare. In addition, nitrogen had a significant positive effect on grain yield. The results revealed that all the traits except for the number of seeds per pod decreased with a delay in cultivation. The interaction effect of the planting date and nitrogen was significant for the total number of healthy pods in the whole plant, the main stem, and the secondary branches. Generally speaking, considering the best time of cultivation can improve grain yield due to its appropriate growth period and an increase in yield component. In addition, applying nitrogen fertilizer, at least one time, can have a positive effect on soybean grain yield.