Because Hypericum perforatum L. distributes in altitude 0 – 2000 m from sea level in Golestan province, this project was performed to introduce the suitable cultivar with the highest amount of effective material. This study was conducted on the cultivars yield of Hypericum perforatum L. at the Chalki Research Station from 1380-1384. Experiment was carried out as split plot based on Randomized Complete Block design with three replications. Treatments included: Furrow–irrigatation as main plot from April to September based on 0, -0.3, -5 and -15 Mpa. Based on Wilting point that was determinated by means of TDR, and Cultivars: two improved (NLC and TOPAZ) and two ecotypes collected from Golestan province as sub plots. The timing of irrigation was determined by TDR apparatus. The aerial parts of plants (20-25 cm from the top) were harvested during the flowering stage for determining of dry matter yield. Dry matter yield was significant different between cultivars (p<0.01) and in irrigation levels (p<0.01). Hypericin amount was not significant different between cultivars but was significant different in irrigation levels (p<0.05). Dry matter yield were higher in Topaz, and local Narrow leaf and Broad leaf Cultivars than NLC, 64.6%, 49.4% and 37.1%, respectively.

This study carried out in Gorgan in loam soil, PH=7.3 and rainfall 630 mm. Sub clover (Trifolium subterraneum) is annual forage legume that was regenerated by reseeding. Density is one of the important factors that is affected on yield per area unit. The best economic harvesting time and the best sowing rate is obtained based on LAI and CGR relation. In order to evaluae the effect of density on yield, LAI and CGR, an experiment was carried out using a randomized complete bloks with 3 replication. Treatments were Sub clover cultivars (Seatonpark, Clare, Geraldton) as main plots and plant densities (600, 1000 and 1400 plant/m2) as sub plots. Plants were sown in the late autumn (December). The number of tillers and their length per plant, LAI and CGR measured. LAI and CGR were affected by cultivars and densities so that were showed different results. Tiller numbers was significantly affected by density (p<0.05) but was not significantly affected by cultivars. Dry matter yield significantly affected by cultivar and desities (p<0.05 and p < 0.01) respectively.   

In an attempt to investigate the effect of shading (source limitation) on dry matter remobilization, yield, and yield components of different rice cultivars, a field experiment was carried out in the research farm of the Agricultural Services Centers of Rezvanshahr during 2007-2008. The study followed a factorial, randomize-complex-block design. The variety and treatment factors, which were respectively at two (Hashemi and Hybrid I) and four (control, light shading, moderate shading, and heavy shading) levels, were carried out in three replications. The treatments in the present study began 10 days before anthesis and ended 10 days after it. The analysis of the results indicated that the shading treatments had a significant effect (at P<0.01) on the seed yield, biological yield, harvest index, the panicle length, the number of grains in each panicle, the number of spikelet on the panicle, and 1000-grain weight. The highest and lowest grain yields belonged to the Hybrid I in the control condition with an average of 8962.3 kg/ha and Hashemi in the heavy shading condition with an average of 1503.3 kg/ha, respectively. The heavy shading treatment had the lowest yield in both types of cultivars. The shading treatments had a significant effect (at P<0.01) on the remobilization of stem and leaves’ dry matter. From among the aerial parts of the plant, the stem had the highest share in the remobilization process. Hashemi cultivar had the least amount of dry matter remobilization probably due to its limited sink space and production capacity. Generally speaking, the results revealed that Hashemi cultivar had a more limited sink space in comparison to the Hybrid I.

Selection of cultivars with high genetic potential and favorable climatic adaption in each region and exact planting date for maximum utilization of effective factors are the necessary management for increase of crop yield. Therefore, the effect of planting dates of 19 May, 29 May, 8 June and 18 June on yield and yield components of four intermediate soybean cultivars i.e. Williams, Zan, L17 and M7 was studied in a randomized complete blocks design with four replicates. Analysis of variance showed that planting date affects on harvest index, total biomass and seed per plant. Effects of cultivar on harvest index, seed weight and seed number per plant were significant (p£0.01). Interaction of planting date and cultivar on harvest and seed number per plant was significant (p£0.01). Increase of planting date of 29 May and Cv. Williams had the most harvest index. Seed number per plant on 29 May (61.6) was significant. Seed number per plant in cvs Williams and M7 were significant. Average of seed number per plant on 29 May in cvs Williams and M7 and also, on 8 June in Cv. Williams were significant. Seed weight in Cv. M7 was the least. 8 June had the highest total biomass.

Introduction Faba bean with scientific name Vicia faba L one of the very old legume crops, is widely planted in temperate regions and high altitude tropical regions. Faba bean used in the human diet and also dry beans, green pods and dry straw used as livestock feed. One way to increase the yield in crop plants unlimited growth such as faba bean is top removal or cut off part of the plant after flowering. So in this regard the effect of top removal and variety on yield and yield components, grain filling rate, grain filling period and chlorophyll of Faba bean were studied. Materials & Methods A factorial experiment was carried out based on randomized complete block design with three replications at farm research of Gonbad University in crop year 2014-2015. The first factor was included faba bean varieties (Zohreh, Shami, Sheshband, Saraziri and Barekat) and the second factors include top removal and non-top removal. In the experiments, seeds of different cultivars of faba bean were planted by hand in ten rows with four meter long and spacing of 12. 5-cm between rows. Phenological stages, including the number of days from planting to poding (R5) and the number of days from planting to physiological maturity (R7) were recorded. Phenological stages on 10 plants were determined based on methods Fehr & Cavieness (1977). Top removal treatment was in stage poding. At harvest, after all plants reached physiological maturity, three m2 of each experimental plot was harvested to determine the yield components, number of pods per m2 and number of grains per pod. In addition, weight of pods, vegetative tissue weight, and seperated leaves from stems with petioles, were measured. Grain yield and weight of thousand grains as dry weight in three m2 of each experimental unit were evaluated. Harvest index was obtained by dividing grain dry weight on the total dry weight at the time of physiological maturity. Grain filling period was calculated from the difference between the number of days from planting to start filling pods and number of days from planting to maturity, respectively. Average of grain filling rate was calculated by dividing the grain yield on the grain filling period (gr/m2/day). Total chlorophyll was measured by using chlorophyll meter device (SPAD) DELTA-T model Results & Discussion Results showed that pod length, 100-seed weight and plant height were affected by top removal. While on other traits there was no significant effect. The effect of variety on biomass, chlorophyll, the number of days from planting to filling and the number of days from planting to maturity was not significant but on the other components of the yield (number of branches per plant, number of pods per plant, number of seeds per pod, pod length, 100-seed weight, grain yield and harvest index), rate and grain filling period was significant. While the interaction of top removal and variety was significant on plant height. Top removal reduced the length of the pod and 100-seed weight. The highest 100-seed weight and grain yield for Saraziri variety was 83. 23 gr/m2 and 77. 65 gr/m2 respectively. While the lowest of 100-seed weight and grain yield belonged to Shami variety with 63. 74 gram and 180 gr/m2, respectively. The lowest harvest index with 32. 32% and the highest of harvest index with 24. 54% were observed in Saraziri and Shami varieties, respectively. The results correlation analysis indicated that positive correlation between seed weight with grain yield (r = 0. 64) and the harvest index (r = 0. 59) were significant, which shows that these two have an important role on seed weight. Strong positive correlation was observed between grain yield with biological yield and harvest index. Conclusion Top removal did not have a great impact on study traits because of dry conditions of the farming location. Low rainfall in the time of poding and high temperature during growth season, especially in after poding stage decreased the growth length of Faba bean. Overall, results of this study revealed that according to the condition of Gonbad-Kavoos, Sarazeri, Zohreh and Barekat varieties were more favorable than other varieties.

To study the effects of nitrogen fertilizer forms on dry matter and nitrogen remobilization, yield, and yield components in rice cultivars, a field experiment was carried out in Geshnian village (Marvdasht) in 2002. A split-plot layout based on randomized complete blocks design with four replication was used. Three nitrogen fertilizer form, including ammonium sulfate, ammonium nitrate and urea were used as the main plots and three rice varieties including Nemat, Dorodzan and Comfiroze were used as the sub plots. The results showed that grain yield, fertilized tiller number, biomass, plant height, panicle length, fertilized panicle percentage, grain protein percentage and nitrogen remobilization from stem and leaves were significantly affected by different forms of nitrogen fertilizers. Also all characters had significant differences among rice varieties. Moreover, the interaction between nitrogen fertilizers and rice cultivars had significant effects on fertilized tiller number, biomass, plant height, fertilized panicle percentage grain protein percentage, nitrogen and dry matter remobilization from stem and leaves. Urea fertilizer had the highest grain yield, fertilized tiller number, biomass, plant height, panicle length, grain numbers per panicle, grain protein percentage, nitrogen remobilization from stem and leaves. Nemat variety showed the highest grain yield, plant height, panicle length, grain numbers per panicle, nitrogen and dry matter remobilization from stem, leaves and flag leaf. In general, contribution of grain dry matter from stem was more than other parts (flag leaf and other leaves). But leaves of Nemat variety remobilized more nitrogen than stem under all conditions. Dorodzan variety had the least biomass, nitrogen and dry matter remobilization from stem, flag leaf and other leaves but this variety had the highest grain protein percentage. There were positive and significant correlation between grain yield, fertilized tiller number, biomass, plant height, panicle length, grain numbers per panicle, fertilized panicle percentage, nitrogen remobilization from stem and leave and dry matter remobilization from leaves.

In order to evaluate the effects of nitrogen fertilizer on yield, yield components and dry matter remobilization of different rice genotypes, a field experiment was carried out in the Rice Research Institute (Rasht/lran) during 1999-2000.A split-plot layout in the basic of randomized complete blocks design with four replications, was used. Three nitrogen levels, including of 0,150 and 300 kg/ha as the main plots and three rice genotypes including of 424, 506 and 507 as the sub plots were used. The results showed that grain yield and dry matter remobilization had significant differences among rice genotypes and different levels of nitrogen. Grain yield and dry matter remobilization in 424 genotype was more than others, and the highest dry matter remobilization was obtained under 300 kg/ha level of urea. Moreover the interation between nitrogen treatments and genotype had significant effects on grain yield and dry matter remobilization. Different rice genotypes and also different plant parts showed different responses related to remobilization of dry matter. 424 and 506 genotypes showed the highest dry matter remobilization under 300 kg/ha and 507 under 0 kg/ha level, of urea. In general, contribution of grain dry matter from stem was more than other parts(like flag leaf and other leaves). There were positive and significant correlations between grain yield and 1000-grainweight and fertile tillers number. Correlation voefficient between grain yield and dry matter remobilization was not significant.  

In order to study the effect of shading (source limitation) on dry matter remobilization, yield and yield components in different rice cultivars, a field experiment was carried out in farm of Agriculture Service Center of Rezvanshahr Township in 2007-2008 year. Statistical design was factorial on the basis of randomize complex block design. Factor of variety was in two levels including (Hashemi and Hybrid 1) and factor of treatments were in four levels including (1.Control, 2.Light shading, 3.Modereat shading and 4.Heavy shading) in three replications. All treatments have been started from 10 days before anthesis up to 10 days after anthesis. The results have shown significant effect at 1 percent level on yield, biological yeild, harvest index, panicle length, number of grain, number of spikelet on panicle and 1000- grain weight. Highest grain yield was in hybrid1 about 8962/3 kg/ha in control condition and the lowest was in hashemi about 1503/3 kg/ha in heavy shading condition. Heavy shading has shown lowest grain yield in both the cultivars. Shading stress has shown significant effect on remobilization of dry matter of stem and leaves. The share of stem was more than other part of plants. Remobilization was less in hashemi that was probably because of little amount of sink capacity and the ability in source production, there were less remobilization. Results have shown sink limitation in hashemi as compare to hybrid

To study the effects of plant density and source limitation on grain yield, yield components and dry matter and nitrogen remobilization in corn (Zea mays L.), a field experiment was conducted at Seed and Plant Improvement Institute in 1998. A strip plot design based on randomaized complete blocks with 4 replications was used. In this study maize hybrids (KSC704 and KSC711) were sown in vertical plots. Density (65, 70, 75, 80, 85, 90 thousand plant ha-1) and topping levels, T1 (control) and T2 (Removing tassel and all leaves above the ear) were assigned as factorial to horizontal plots. Results revealed that toppng at two weeks after anthesis did not have any adverse effect on grain yield. Therefore, a considerable quantity of forage could be harvested without any reduction in grain yield. The highest yield of green fodder (5.45 tha-1) was obtained from 90 thousand plant ha-1. Although topping caused an increase in 1000 kernel weight by 7 percent compared to control, but there was no significant difference in their grain yield. Remobilization of dry matter and nitrogen from different parts of th shoot (leaves and stem) to the grain responded differently and among them stem contributed more. Maximum remobilization of dry matter from stem (58%) was recorded in 80 thousand . plant ha-1 which had significantand positive correlation with grain yield.