JOURNAL OF RESEARCH IN CROP SCIENCES
Year:2010 | Volume:3 | Issue:9|Papers Count:10

To investigate the effects of different amounts of nitrogen, planting density and number of seedling in the main farming on morphologic qualities, functional components and quantitative and qualitative functions of ratoon rice production cultivars Sangtarom, an experiment was conducted on a field in Babol, in 2008. Split factorial experiment was conducted in randomized complete block design in three replications. In this experiment four levels of nitrogen fertilizer (0, 46, 69, 92 kg ha-1 from the urea fertilizer source) were used as main factor and sub factor, including the first two planting densities (120 and 40 plants per square meter respectively, sowing pattern 10×8.3 and 16.6×15 cm square). For the second factor two planting methods frutescence (single seedling) and univalve (3 seedlings or bud), were used respectively. The result of experiment indicated that maximum ratoon production consumption, respectively 46 and 92 kg N ha-1, also the maximum ratoon production obtained under density 120 plants in square meter and with the three seedlings could create an increase in some functional components, such as the number of panicles in square meter, in the total number of spikelet in panicle, in the number of filled spikelet and in the weight of thousands seeds. Also the quality of amiluze under the consumption of 92 kg N ha-1 by density 120 plants in square meter and also under the condition of univalve planting (3 seedlings) reached to its maximum value.

To evaluate the plant density and nitrogen fertilizer effects on yield, components, and percentage protein of Durum wheat var. Aria and experiment was carried out in south west of Khoy during 2007. Plant density in three levels (300, 400, 500 grain in m2) as the first factor and nitrogen fertilizer in five levels (0, 50, 100, 150, 200 kg per hectare) as the second factor. Result of variation analysis showed that except of leaf number and harvest index, plant density had meaningful effect on other traits. Comparison of the means showed that most grain yields by 659.2 grm-2 obtained in 500 plants per m2. The various levels of nitrogen fertilizer except of leaf number and harvest index had meaningful effect on other traits. The highest grain yield by 711.8 kgm-2 was obtained in 200 kg nitrogen fertilizer per hectare. The opposite effect of nitrogen density only had meaningful effect on protein percentage trait. The highest nitrogen percent (15/36) was obtained in 200 kg nitrogen per hectare by 300 plants per square meter density. There was a strongly correlation between grain yield by biological yield R2≤0.947 and between yield component. The rachis numbers by R2≤ 0.947 had most positive correlation by grain yield. By noticing results of this experiment, it is recognized that durum wheat var. Aria by 500 grain per m2 density and 200 kg nitrogen per hectare is recommendable for planting in the zone.

To study the effects of different planting dates and plant density on morphological traits of two wheat lines an experiment was performed at Moghan Agricultural Research Center in 2008. The experiment was done in split-split plot design. Four planting dates (November 6‚ November 21‚ December 6 and December 21) were assigned to plot‚ two wheat varieties to sub plot and four seed density (300‚ 350‚400 and 450 grain per square meter) to sub subplot with three replications. The results showed that the November 6th planting with 7397 kg/h was one of the best planting times based on grain yield. There was significant difference among wheat varieties based on harvest index‚ number of spikelet‚ plat height and panicle length with the probability of %1‚and with regard to the number of grain in a panicle this difference was around %5. Regarding those features there were not significant differences between Arta and Moghan-3. Different Grain densities for grain yield‚ panicle length and number of grain in the panicle in the %5 probability were significant. Seed density of 350 per square meter was 7170 kg/m‚ panicle of 9.08 and 42.43 grain in a panicle. Also‚ the effect of planting time on grain yield‚ harvest index‚ number of tillers‚ and peduncle length was significant. The correlation of variety and density on grain yield was meaning full‚ too. Third planting date‚ and second density had the best results in grain yield. Although variety was not of significant for grain yield‚ Moghan-3 had more grain yield compared to Arta. For Moghan-3 variety third planting time and for Arta the first planting time seems the best. We also made the correlation between variety density significant so that Moghan-3 variety in second density and Arta variety in third density produced the most grain yield. Finally‚ based on these experiment results it is recommended to plant Moghan-3 with 350 seed density in a square meter in the first half of November and Arta with 400 seed density in the second half of November. In this study the correlation between grain yield and fertile tiller was found to be positive but non-significant‚ with the number of spike lets negative and non-significant. So it is useful to use ideal fertile tiller varieties when we want to choose suitable planting varieties.

To study the effect of harvesting time on the quantity and quality of sugar beet, 3 harvest dates (October 22nd, November 6th& November 21st) and on the five varieties of sugar beet (Afshari, Zarghan, Shirin, Rasul & jolgheh) were evaluated. The study was conducted in factorial experiment based on complete block design with three replications in Khoy Agricultural Research Center during 2009. Cultivation operations in mid-April, based on recommendations and the same for all treatments were performed. Analysis of variance showed significant differences between cultivars in terms of sugar content, white sugar content, alkality, and sodium and nitrogen impurities. Variety of Rasul sugar content and white sugar content was more than other varieties. The difference between harvesting dates of the root yield, sugar content, white sugar content, white sugar yield and sugar yield was significant. November 21st harvest root yield found with 94.360 tons per hectare more than previous harvest dates. The highest sugar content, white sugar content was related to the date of November 21st and was higher than other harvest dates. The highest sugar yield and white sugar yield respectively, 12.98 and 10.34 tons per hectare belonged to November 30th harvest. That was of significant difference rather than two other dates.

To investigate the effects of cultivar and harvest date on quantitative and qualitative characteristics of autumn sown sugar beet, an experiment was conducted in Kashmar agricultural research station in 1389-1388. The experiment was conducted as randomized complete block design with four replications and split plot arrangement. The main plots included four cultivars (7112, SBSI002, GIADA and RIZOFORT) and factors of subplot were three harvest dates (April 20th, May 10th and May 30th). The characteristics included root yield, bolt percentage, sugar content percentage, white sugar content percentage, sugar yield, white sugar yield, for each harvest Dates was measured. Results showed that among varieties of sugar beet, root yield, bolt percentage, sugar content percentage and white sugar content percentage were different significantly. The Giada was the most suitable cultivar for Kashmar region because of the highest root yield (49.17 tons per hectare) and the lowest percent of bolting. All characteristics by harvest date were affected significantly. The interaction effect of cultivar and harvest date were significant on Root yield, Bolt percentage, Sugar content percentage, white sugar content percentage, sugar yield, white sugar yield. For achieving the highest Root yield, Sugar content percentage, white sugar content percentage, sugar yield, white sugar yield, the harvest date of May 30th is recommended for the Kashmar region.

This research was conducted to evaluate mini-tubers production potential in micro-tuber different potato cultivars under greenhouse conditions in Ardabil Agricultural and Natural Resources Research Station during 2010. Micro-tubers less than 1g of eight potato cultivars (Satina, Caesar, Marfona, Luta, Agria, Markies, Hermes and Savalan) were cultured on completely randomized design with three replications. The micro-tubers were planted in Biolan and Punch bed planting to volume ratio of 1:1 in plastic as pots 10×10 cm. Analysis of variance for measured traits showed that potato cultivars in all of traits had significant difference. The maximum mini-tuber number per m2 belonged to Agria cultivar; mini-tuber weight per m2 and mini-tuber size average belonged to Savalan cultivar; mini-tuber number and weight higher than 10 g belonged to Savalan and Satina cultivars; mini-tuber number and weight between 7-10 g belonged to Agria and Satina cultivars.

To study the effect of sowing date and density of wild oat on growth and development of wheat an experiment was conducted in randomized complete block in four replications in forms of split-plot in frame of basic design in 2004-2005 and 2005-2006 at Farm Experimental-Research Islamic Azad University of Shooshtar, Khouzestan. Treatments' including sowing date of wild oat (16, 22, 26 November, 1, 6, 11, 16, 22, and 26 December) as main plot, and six densities (0, 20, 40, 60, 80 and 100 plants m-2) as subplot was conducted in competition with winter wheat on December 6th. The results analysis of growth indices of wheat indicated that with increase growth day degree (GDD), the best status of total dry matter (TDM), crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR), leaf area index (LAI), leaf area ratio (LAR), specific leaf area (SLA) and leaf weight ratio (LWR) belonged to free plots and the latest sowing date (26 December). In addition, by increasing of density or sowing date of wild oat before wheat decreased total dry matter 61 and 70%, crop growth rate 45 and 58%, relative growth rate 57 and 89%, net assimilation rate 92 and 100%, and leaf area index 97 and 100% than density 0 plant m-2 and the later sowing date of wild oat in final phase (2500 dd), showed decline respectively.

Climate change and increase in the temperature are important ecological issue in human life which can affect regional agricultures. Evaporation, potential transpiration, and water requirements of the culture pattern in every region are affected by changes in the climates. The studied area is located between 36°00'N & 37°05'N, and 58°20'E & 60°08'E, with an average temperature of 12.5°C and annual precipitation of 278.6 mm. Results assert that water requirement has been ascending within the 50 recent years, especially during the second 25 years (1975-2000). Evapotranspiration for the 2000-2050 periods was calculated by means of The Global Climate Change Model. The ratio of the recent-50-year January to September monthly evapotranspiration to the coming same period is bigger than one; the 1.05-1.22 ratio indicates a 22 percent growth of water requirement in the period ending in 2050. The total net water requirements for the current culture pattern were estimated at 410 million m3 per year; while the figure for the next 50-year period -with a 19 percent of increment- will be 490 million m3. Water requirement for a majority of the culture pattern will be 22 percent up. The least increase was 14 percent, which was calculated for alfalfa. Exceeding the yearly available water supplies, in the changing conditions of climate, agricultural water consumption in the plain touches 1388.4 million m3. Given the climate change, the shortage will reach 198 percent in June and July. The present critical water shortage coefficient of 0.98 (yearly) and 2.4 (monthly) will go up to 1.15 and 2.4. These figures indicate extremely crucial conditions in the region. Findings assert that even optimistically assuming that the water supplies will be enduring, agricultural water consumption (i.e. the major type of consumption) will dramatically increase, due to the warming weather, climate change originated in industrialization, and greenhouse gasses; so managerial solutions are needed to tackle the problem.

To study the effect of planting dates, seed rates and row spacing on grain yield and yield components of a lentil genotype (Filip 92–12L), an experiment was conducted in research farm of Islamic Azad University of Shirvan during 2008 cropping season. The experiment was performed as split factorial on the basis of randomized complete block design with 3 replications. Planting dates were autumn and spring which located in main plot. Seed rates included 100, 150, 200, 250 and 300 seed per square meter and each seed rate planted in four row spacing of 15, 20, 25 and 30 centimeters. Seed rates and row spacing located in sub plots as factorial. Recorded traits were biological yield, grain yield, thousand kernel weights, number of pod per plant and number of seed per plant. Results showed that the highest number of pod per plant (19) and The highest number of seed per plant (22) produced in seed rate of 250 seed/m2 and row distance of 15 cm. Seed yield in row distance of 15 cm and seed densities of 250 and 300 seed/m2 in were respectively 1130 and 1200 kg/h and the most biological yield obtained from row distance of 15 cm and seed rate of 300 seed/m2. In terms of planting date, the highest seed yield was observed in seed rate of 250 seed/m2 in autumn planting. According to the results, seed rate of 250 seed/m2 with row spacing of 15 cm is advisable for autumn or spring planting of lentil and totally autumn planting is more suitable.