PLANT AND ECOSYSTEM
Year:2011 | Volume:7 | Issue:27-2 (SUPPLEMENT)|Papers Count:9

In order to determine the effect of different amount of nitrogen application in different sowing dates on phonological traits, plant height and seed yield of canola (Brassica napus L.) Hyola 401 cultivar, an experiment in a randomized complete block design arranged in a split-plot with four replications in Biekola Agriculture Research Station in Neka city during 2008-2009 was coducled. Five sowing dates including 29 October, 8, 18, 28 November and 8 December were considered as main plots and four levels of nitrogen urea fertilizer application including 150, 200, 250 and 300 kg/ha urea were considered as sub plots. Results revealed significant of sowing date and nitrogen for number of days to flowering, number of days to end of flowering, plant height, number of pods per main raceme, number of pods per plant, number of seeds per pod, 1000 seed weight and Seed yield. The nitrogen effect was significant on each studied traits except duration of flowering. Interaction sowing date and nitrogen application were not significant for more studied traits except the number of pods per plant and 1000-seed weight. Among yield components, number of pods per main raceme and pods per plant had significant correlation with seed yield, indicating variations of these traits in different sowing dates, and also more effect of different nitrogen levels on seed yield. Significant positive correlation was observed between seed yield and each phonological trait, indicating in first and second sowing dates and also high amount of nitrogen levels make increasing amount of phonological traits and seed yield. In the first sowing date the seed yield related to four nitrogen application levels were 2864, 3026, 3276 and 3707 kg/ha respectively. For the fifth sowing date, the seed yield were 1754, 1835, 1973 and 2268 kg/ha respectively. Therefore one of the effective ways for compensating of decreasing yield components and seed yield due to late planting date is increasing amount of nitrogen application.

This study conducted in Khaveh station related to Varamin Natural Resources and Agricultural center in summer 2008. The experimental design was based on a randomized complete block with split split block with three replications. Treatments include winter wheat residue (Triricum aestivum L.) as a major factor in two levels including (burning residue and non-burning residud) and Tillage as a secondary factor in three levels include: No tillage, disk, Plow+disk and nitrogen as a bi secondary factor in three levels (0, 200, 400 kh/ha). The measurements included plant height, yield of forage corn, leaf area index and dry weight in stages of 7-8 leaves and tasseling. Results indicated that the effect of wheat residue had no significant difference on measurements except leaf area index in stage of tasseling. The most leaf area index (3.26096) related to non-burning residue. The most height (84.944cm), leaf area index (0.96) and dry weight (5.6944 g/plant) in stage of 7-8 leaves was related to No tillage and the most leaf area index (4.13), dry weight (90.10 g/plant) and yield of forage corn (61.889 ton/ha) in stage of tasseling was related to No tillage treatment.

Due to the investigation of the effect of date of cropping on seed and oil yield in different variety of canola, an experiment was carried out in the design of split plot in randomized complete block with four replications in Karaj. In this study, date of planting as main factor in two levels (Normal-Delay) and variety as sub factor (Ebonite, Olpro, Celsius, Geronimo, Arc-2, Dexter, Okapi, Herkules, Dunte, ORW20-3002) cosidered. Characteristics such as: the number of siliques per plant, the number of seed per silique, seed and oil yield were measured. The results shown that the delay cropping is more effective than normal cropping abate tendency in all of the characteristics. In normal date of cropping, varieties of Ebonite had the highest and Okapi the lowest average of seed yield (4241 and 2353 kg.ha-1, respectively), so in delay date of cropping, varieties of Olpro had the highest average of oil yield 773.5 kg.ha-1 and Geronimo had the lowest average of oil yield 432.9 kg.ha-1.

Manure and urea (46% nitrogen) are important resources for organic and chemical nitrogen which improve the crop production. However there are many factors consist of low density of manure, rapidly nitrification and environmental pollution that limit the application of these materials. In this research, the suggested solution was the densification technology with molding manure composit into pellet. Durability properties of pellets determined within moisture content range 11 and 24% (w.b.) and particle size of materials were observed. Obtained results showed that hardness and durability of pellets increased with decrease in moisture content and particle size of material. This study focused on the evaluation of the effect of pellet processing on decreasing of nitrification in wheat crop (Triticium aestivum.). In this research, usage of fertilizer pellets was evaluated on the base of randomized complete – block design. These treatments consist of different compression and three different urea rates.According to the statistical analysis, significant difference between treatments was observed. In addition through mean comparison by Duncan test, the seventh treatment with the most compact and least urea level, was high amony other treatments.Due to slow decomposition of compacted pellet, there was an increase yield in this treeement, that results in gradual. Nitrogen release in soil and observing the increase of Nitrogen efficiency in wheat crop.Therefore pellet herlilizer canbe considered as a resource of Nfertilizer that cannot be analyzed because its durability and density. The solwrelease feature of Nitrogenleads to increasing Nitrogen efficiency I soil. In addition the use of these fertilizers causes the reduction in leaching losses and enhancing Nitrogen uptake.

In last years, development of Biology science, importance of protection of environment and high demand to nutrients leads researchers to consider the biological materials. In this aspect the increasing rate/area of lettuce and pepper in agriculture is very important. In this research, the effect of five isolates of Trichosderma harzianum include T1, T2, T3, T4 and T5 on increasing the growth of lettuce and pepper were carried out as RC Design with four replications under greenhouse conditions. For this experiment, 0.5%, 1% and 1.5% inoculums per pot were used. Five seeds of each other were cultivated in each plot. Shoot and root fresh/dry weight, their length, number of leaf and stem diameters were measured after 40 and 30 days for lettuce and pepper, respectively. The results showed that isolates with various concentrations had significant different effect on length and shoot and root fresh/dry weight of lettuce and pepper (P<0.01 and 0.05) by Duncan multiple rang test (DMRT). T1 and T2 isolates had the highest and lowest effects on the length and shoot and root fresh/dry weight of lettuce and pepper respectively. Although, lettuce and pepper were also significantly different at level 0.01 because of growth effects of isolates, growth effects of isolates on the lettuce were relatively more than pepper.

In order to Study the effect of concurrent rice-fish culture on yield and yield components of rice (Oryza sativa L.), an experiment was carried out with five varieties of rice (Sadri, Binam, Tarom, Hashemi and Hasani) in randomized complete block design with three replications, with two separate neighboring block design (concurrent rice-fish culture and rice-alone culture as control) in Astara in 2009. The data obtained from the measurement of the characters studied of rice varieties in each design were separatly analyzed and results compared. The results of combined analysis of variance of characters in concurrent and rice alone culture showed that between two conditions of culture, there was a significant difference at the 1% probability level in rest characters except harvest index. Also, among the varieties studied there was a significant difference at the 1% probability level regarding to all the characters. The effect of culture conditions at variety was meaningful at the %1 probability level for plant height, tiller number per bush, biological yield and harvest index. Results indicated that all varieties had the highast yield in concurrent rice-fish culture than rice-alone culture and Binam variety with average 4977 kg/ha had the highest paddy yield in concurrent rice-fish culture.

In order to evaluate the relationship between quantitative and qualitative features with yield, ten promising lines of rice with Hashemi and Kadous races as checks were compared at Iran rice Research Institute in Rasht during 2006, 2007 and 2008. The experimental design was randomized complete block design (RCBD) with four replications for all three years. In this study, eighteen features including yield and quantitative and qualitative traits were assessed. According to the results of mean comparison in respect of yield, Kadous race with 5426 kg/h showed the highest yield and lines No. 3,8 and 9 with 4450, 4435 and 4378 kg/h respectively showed the highest productivity. Estimating of simple correlation coefficient among the features based on 3 years average manifested that the highest positive significant correlation coefficient with yield was for 100 seed weight and tiller number. There was a negative significant correlation between yield and plant height. In the factor analysis of the features, generally five independent factors justified 84% of the total variances. These five factors were, shape and size of the seed, morphological features of the plant, cooking quality and yield and its components. Meanwhile, the forth and fifth factors were so important to increas the yield. Therefore, the features of these factors including, 100 seed weight, seed per panicle, days maturity and seed length important in selecting the lines with desirable yield. Features such as days to heading, plant height, panicle length, milling quality, glutinization consistence, glutinization temperature and seed weight had less importantance.

In this study GA3 and Urea were sprayed in different concentrations in isolation in combination on ten years old Satsuma mandarin (Citrus unshiu) trees on citrange root stock during late bloom. The experiment was performed in Mahdasht garden of Sari city in north of Iran. The experiment was carried out in randomized Complete Block Design (RCBD), in 16th May with 4 replications and 6 treatments including: control, GA3 (15 mg/l), GA3 (15 mg/l) + Urea %1, GA3 (30 mg/l), GA3 (30 mg/l)+ Urea %1 and Urea %1.The results showed that, GA3 (15 mg/l) treatment reduced significantly fruit drop percentage and increased fruit retention percentage, compared with control. Whereas the lowest amount of fruit retention observed in GA3 (15 mg/l) + Urea %1 treatment. Also in GA3 (15 mg/l) treatment, the ratio of peel weight to peel diameter increased significantly compared with control, it can cause increase in peel condensation and firmness and decrease in puffiness. Dueto decreasing peel diameter in all treatments, fruits had thickness peel but firmness.

The magnitude and nature of N losses vary depending on the timing, rate and method of N application, source of N fertilizer, soil chemical and physical properties, climate conditions and crop status. In general, ammonia volatilization is the major pathway of N loss in irrigated rice.Since the plant growth reflects the total N supply from all sources, plant N status will be a good indicator of N availability to crops at any given time. Leaf colour chart (LCC) is simple portable diagnostic tool, to determine the timing of N top dressing. Field experiments were carried out to compare the effect of N split application and LCC on the grain yield of Fajr variety in 2009. A randomized complete block design with three replications and twelve treatments (LCC management and different N rate of 45, 90, 135 kg N per hectar with three timing application. All treatments showed significant grain yield increase relative to zero-N control in three fields. Yield increase was shown up to 135 kgN/ha because of low N supplying content. Grain yield of LCC treatments were higher than split treatments. As a result LCC treatments indicated that N management based on LCC shade 5 helped avoid over application of N to rice in fajr variety.