A Very Simple Model For Simulating Sugar Beet Yield For Potantial Production

 Sugar beet is one of the most important crops in Iran. The potential yield and its limitations can be estimated using a simple model and long-term weather information. The present study was aimed to develop a very simple model for sugar beet. this model is a dynamic and mechanistic simulation model to simulate sugar beet growth and sugar accumulation for potential production condition. Therefore when the water is not a limiting factor for plant growth, maximizing intercepting solar radiation during growth season has major important. Because in this condition, solar radiation is a limiting factor for plant growth. Therefore selecting suitable planting date is important. Crop simulation models help us to determine planting date and to asses risk production. The model uses a few relationships to define leaf area development as a function of accumulated thermal time units. Biomass accumulation was simulated as a function of fraction of photosynthetically active radiation interception and radiation use efficiency. The growth of root is dependent on the biomass accumulation. The model uses a daily time step and readily available maximum and minimum temperatures and solar radiation. The model was tested for different planting dates at Ardabil in Iran. The model performed satisfactory in predicting the leaf area index and root biomass of sugarbeet as influenced by potential production condition. The simulated average root yield and leaf area index and its range were similar to observed root yield and leaf area index (root mean square error for root yield and leaf area index were equal to 3.97 t ha-1 and 1.3 respectively)

Investigation of Correlation between Traits and Path Analysis of Corn (Zea mays L.) Grain Yield at the Climate of Ardabil Region (Northwest Iran)

In order to study correlation between some traits and yield components of corn and to determine the most effective factors on its yield, an experiment was conducted at the agricultural research farm of university of Mohaghegh Ardabili in 2007. The experiment was conducted as a split plot in a randomized complete block design with four replications. Main plots were allocated at three levels to different planting dates (10, 20 May and 30 June) and subplots were allocated at the different levels of nitrogen fertilizer (0, 75, 150, 225 Kg N ha-1). The utilized corn seed was SC 404 hybrid. Sequential path analysis was used for evaluation of relationships between yield and yield attributes and to eliminate less important variables by using SPSS. Results showed that kernel per ear has the most correlation (r = 0.53) with grain yield. The grain yield and kernel per ear indicated negative and significant correlation with grain thickness (r = -0.33 and r = -0.52 respectively). The correlation between grain protein and thickness was negative and significant, too (r = -0.52). Results obtained from path analysis revealed that kernel per ear has more importance for selecting corn cultivars with high yield among different traits. Kernel per row and grain length had an effect on grain yield. Thus, these two traits can be attend in breeding programs and also be effective as a potential traits in improving desired corn cultivars

Evaluation of Drought Tolerance Indices and their Relationship whit Grain Yield in Wheat Cultivars

To illustrate the effect of drought stress on grain yield of 8 wheat cultivars and evaluation of drought tolerance and susceptible ones, two trials were established using randomized complete block design with three replications at research field of University of Mohaghegh Ardabili, Iran. In the first trail, drought was aplplied and irrigation was done once in order to seed germination, but in the second trail, regional normal irrigation regime was used. Wheat cultivars were Azar2, Agostave, Phinican, Sardari, Soysonz, Gaspard, Gascogen, and MV17. Results showed that according to the Fernandz grouping, Azer 2 was suitable for both stress and non stress conditions. MV17, Gascogen and Gaspard were recommended for optimum environment. Sardari cultivar was identified suitable for severe stress environment. Finican, Soysonze and Agostave cultivars had few grain yields in both stress and non stress conditions

Gama-Tocopherol Accumulation and Floral Differentiation of Medicinal Pumpkin (Cucurbita pepo L.) in Response to Plant Growth Regulators

Changes in biochemical and agronomical characteristics were studied in medicinal pumpkin (Cucurbita pepo L.) plants under different treatments with plant growth regulators (PGRs). The seeds were subjected to priming with PGRs before planting and plants unerwent foliar sprays with different solutions of PGRs at 10 day-intervals after flowering. y-tocopherol (y-toc) content of grains was found to be increased under gibberellic acid (GA3) treatment. The accumulation of y-tocopherol in the grains of GA3 treated plants was approximately 19.5 % higher than the control and reached 220.2 mg kg-1 dry pumpkin grains. The number of female flowers per plant was positively affected by PGRs and was 10.1 and 1.89 respectively, in the naphthalene acetic acid (NAA) and GA3 treated plants. A significant efficiency of treatments was observed upon fresh fruit yield. The yield increased from 4831 t ha-1 in the control to 6820 t ha-1 with NAA treatment. Priming treatments increased seedling emergence rate and percent. The highest seedling emergence rate was found in GA3 treated seeds

Effects of Nano-Iron Oxide Particles on Agronomic Traits of Soybean

This study was performed to determine the effect of nano-iron oxide on soybean yield and quality. Field experiment was designed based on randomized complete block design with three replications. Treatments were five levels of nano-iron oxide (0, 0.25, 0.5, 0.75 and 1 g l-1). Results showed that nano-iron oxide at the concentration of 0.75 g l-1 was increased leaf + pod dry weight and pod dry weight. The highest grain yield was observed with using 0.5 g l-1 nano-iron oxide that showed 48% increase in grain yield in comparison with control. Other measured traits were not affected by the iron nano- particles