فصلنامه گیاه و زیست بوم
پیاپی 29 (زمستان 1390)

Nitrogen is the most important nutrient for wheat growth and it is as primary nutrient element for plants. Time and amount of N application is an important factor to meet the plant requirement, farmer economy and environmental aspects.In the recent years, the chlorophyll meter has been a new device which can help the farmers to recommend the nitrogen fertilizers rapidly. This greenhouse experiment was conducted in a completely randomized design with six different treatments (0, 50, 100, 150, 200, 250 N Kg/ha) in nine replications.Wheat (Triticum aestivium L) sampling was done from the early growth stages up to the harvesting time. Total N, N-No3 were determined in this samples (soil, plant).The chlorophyll meter reading data were collected during the wheat growth. The results shoued that N application had significant effect on the chlorophyll content of leaves. The critical value of chlorophyll meter reading was 48.5 for this experiment. In this study 100 Kg/ha urea had the highest yield.This research was conducted for the purpose of preventing the uncontrolled use of nitrogenon fertilizer and environ mental pollution.

One of the biotic stress that effects on plants is the allelopath Allelochemical compounds have impacts on the processes such as photosynthesis, respiration, water absorption and enzyme activity of the growth and metabolism plant. Canola is a crop and strategic plant that have allelopathic potential. Ascorbate is on antioxidant compound that improves plant response to a biotic stress. According to the above explanation, the aim of this research was the study of exogenous ascorbate on the growth parameters and photosynthetic apparatus of soybean in the presence of canola aquatic extract. Aquatic extract of canola root and shoot prepared in tree leaf stage and extracted in 50% and 100% concentration. Ascorbate 1,2mM was added to the aquatic extract and the effect of extract separately and with ascorbate in 9 treatment bases on random completely design in Hoagland culture on soybean was evaluated. The results showed that canola aquatic extract decreased the growth parameters such as the length of root, hypocotyls and shoot of soybean, this inhibition effect was significant in shoot extract. On the other hand, this inhibition was seen in the amount of chl a,b, soluble sugars in root and leaf of soybean. Addition ascorbate to canola aquatic extract improved the growth parameters, increased the soluble sugars and chl in soybean in response to canola extracts.

Since the plant reflects the total N-supply from all sources, plant N status can be a good indicator of N availability to crops at any given time. The chlorophyll meter (SPAD) and leaf colour chart (LCC) are simple, portable diagnostic tools that can measure the crop N status in situ in rice fields to determine the timing of N top dressing. To study optimal N-management an experiment was carried out in Rice Research Institute in mazandaran, in 2009. A test material has been evaluated in a Randomized Complete Block Design with three replications. Shirudi variety was grown under eight treatments, including zero-N control, two splits, chlorophyll meter 35, 37,40, LCC 4 and 5. Both LCC and SPAD can be used to improve N management for rice. The optimal SPAD threshold used to determine the timing of N-application was 37 LCC treatment indicated that N-management based on LCC shade 5 helped to avoid over application of N.It is suggested that when N-management technology such as real time N-management (SPAD and LCC) were used, it would be possible to avoid the over application of N fertilizer by rice farmers.

In this research the effects of different concentration of urea, boric acid and calcium chloride solutions on the vegetative, sexual growth of strawberry cultivar camarosa (Fragaria × ananssa Duch. Cv. Camarosa) were studied. The experiment was carried out on factorial experiment based on the complete randomized blocks design with three replications. The first factor included the inclusive of urea in 3 treatments 0-100and 200, second factor boric acid in 3 treatments of 0-1and 1/5 ppm and the three factor was calcium chloride in 3 treatments of 0-1000 and 1500 ppm the. results indicated that the treatment of urea (200) ppm had the greatest effect on the amount of leaf number, calcium chloride (1000) ppm, boric acid (1) ppm and urea (100) ppm had the greatest effect on the amount of fruit number. Calcium chloride (1500), boric acid (1/5) ppm and urea (100) ppm have the greatest effect on the amount of fruit weight. Among the different treatments of calcium chloride (1500), boric acid (0) and urea (200) ppm showed the greatest effect on the of the petiol length. Calcium chloride (0), boric acid (1/5) ppm and urea (0) ppm had the greatest effect on the amount of fruit width.

In order to study the effects of NaCl salinity on growth parameters in eggplants growth under natural conditions, an experiment was performed in completely randomized design (CRD). The salinity treatments were in six levels of NaCl concentration and were added to irrigation water (EC=219) in 10, 20,40,60, 80, and 100 millimolars of NaCl while the irrigation water was used as a control. Then the 8-10 weeks old eggplant seedlings of three local predominant cultivars (local Jahromian,longDezfolian and round Indian), were planted in 9 kg plastic pots filled with the dominant soil of the zone. Salinity treatments were applied for 5 months and growth parameters such as leaf number, plant height, root length, total biomass and shoot/root ratio of each plant were measured during the period of the experiment. The results showed that NaCl salinity caused lower number of leaves, decreased plant height, root length, plant total dry weight and the ratio of shoot/root weight in a correlated pattern with salt increasing level in comparison to those control treatments, but there was no significant effect on stem diameter. On the basis of the studied parameters the Indian round cultivar was the most tolerant in comparison to other types and the long Dezfolian cultivar was the most sensitive one against NaCl salinity.

An experiment was conducted to apprise the effects of nitrogen supply on grain protein percentage and nitrogen use efficiency of wheat (Triticum aestivium. cv. Pishtaz) in the Educational-Research Agriculture of the Islamic Azad University (IAU), Saveh Branch. A randomized complete block design was used with three replications. Treatments included five levels of Nitrogen fertilizers (N1: 0; N2: 40; N3: 80; N4: 120; N5: 160 N kg-1) and four split applications of Nitrogen fertilizer (T1: Use fertilizer completely in the cultivation phase, T2: One third in the cultivation phase + two third in the tillering phase, T3: one third in the cultivation phase + two third in the elongation phase, T4: One third in the cultivation + one third in the tillering phase + one third in the elongation phase). The results demonstrate the higher nitrogen application positively associated with the higher grain yield, grain protein percentage, and grain protein yield of wheat. On the other hand, nitrogen use efficiency (NUE), nitrogen agronomic efficiency (NAE), and nitrogen physiologic efficiency (NPE) were adversely connected to the increase of the level of N application. In addition, the highest protein percentage observed in T2N5 treatment of 12.45 per cent. The time of the nitrogen utilization was significantly affected grain yield, protein percentage, and nitrogen agronomic efficiency.

Dianthus is one of the most important ornamental plants and its cultivation has a long history. It is used as a cut flower and also pot plant. Due to ease of production and reasonable price, it has a valuable position, economically. In this study, the effect of Benzyl adenine, in 3 different concentrations of 25, 50 and 100 mg/l as a short time treatment for 48 hours and nanosilver of 2 different concentrations (2 and 4 ppm), 300 ppm 8- Hydroxyquinoline sulfate and 3% sucrose as a long time treatment on dianthus cut flower longevity was studied. All of the flower containers were kept in average temperature of 20˚C, relative humidity of 80% and 14 hours photo period, supplied by fluorescent lamp (15 µmol/m2.s). The quality characteristics including: vase life, total soluble solid, stem bending rate, electrolyte leakage index, chlorophyll content and solution uptake were properly measured and statistically analyzed. The results showed that the short time treatment of benzyl adenine in 100 mg/l concentration plus 4 ppm nanosilver and 3% sucrose totally had the highest effect on quality characteristics and longevity of dianthus.

To evaluate the effects of different levels of zinc and copper intake as soil and foliar application and interaction of these two elements on wheat’s qualitative and quantitative characteristics, the research was done as a factorial experiment in randomized complete block design with 3 replications in Greenhouse College of Agriculture, Islamic Azad University Saveh in November 2008. The factors of this research included complex of 3 levels of Soild mix of zinc, copper and 2 levels of spray of these two elements. The Results did not show significant effect of fertilizer on protein and percentage of tiller and Grain number in spike. The Results showed that the application of zinc and copper on soil compared with control significantly increased Grain yield, grain weight, zinc and copper content of seed, concentration zinc and cooper on seed, concentration zinc and copper on the shoot and fertile tillers, while application of zinc on soil and spray zinc as compared with control significant content absorbed copper and zinc on seed, concentration copper and zinc on the shoot. The results showed that the application of zinc on soil and spray copper as compared with control View caused significant increase of content absorbed zinc on seed, concentration zinc on seed and concentration zinc on the shoot while application of copper on soil and spray zinc as compared with control View caused significant increase of content absorbed copper and zinc on seed, concentration copper and zinc on seed, concentration copper and zinc on the shoot and fertile tillers. The results showed that application of copper on soil and spray copper as compared with control View caused significant increase of concentration zinc and copper on seed, content absorbed zinc and copper on seed, concentration zinc and copper on the shoot and grain weight. The results showed that spray copper and zinc as compared with control View had significant increase of concentration zinc and copper on seed, concentration zinc and copper on the shoot and content absorbed copper on seed. The results showed that zinc and copper had a negative Interaction on each other. The Results in this study showed that the application of zinc and copper together on soil had the highest effect on yield of wheat.

Zinc deficiency has been reported for some crops in Iran. The published reports indicated that a considerable portion of applied has not been absor bed by the first plant and thus could be used by subsequent crops. The objectives of the present experiment were: the study of (i) The effects of residual Zn on growth and of rice Zn concentration and uptake by rice (Oryza sativa L.), (ii) the Growth and Zn concentration and uptake as affected by Zn chemical forms.Twenty surface soil samples (0-30cm) from major paddy rice fields in Fars province were used and treated with 3 levels of Zn (0, 5, 10 mg/kg soil as ZnSO4.7H2O) and other nutrient elements, then planted to rice (first crop). Pots after added all essential nutrients except Zn were replanted to rice (second crop) for 60 days. Shoot dry weight, relative growth and Zn concentration and uptake were used as plant responses. Soil samples taken before rice and Zn concentration were determined. In addition, chemical forms of native and applied Zn were determined by sequential factorial method.The results indicated that although residual Zn had no significant effect on dry matter of rice, it markedly increased Zn concentration and uptake by this crop. Furthermore, extractable Zn before the second crop determined by any of the three methods was higher than critical level. The results of present study showed that carbonate form is responsible for the observed residual effect of ZnSO4 in these calcareous soils Multiple regression equations revealed that the carbonate form was significantly correlated with Zn concentration and uptake in rice.