JOURNAL OF RESEARCH IN AGRICULTURAL SCIENCE
Year:2006 | Volume:2 | Issue:1|Papers Count:10

In order to evaluate the grain yield and yield component in sesame, an experiment with 112 genotypes in an augment design was conducted at the Research Station College, located at Lavark, Najafabad. The characters evaluated comprised: days to 50% flowering, days to maturity, 100-seed weight, plant height, Number of capsules per plant, first node height, seed weight per capsule and grain yield per plant. The correlation between grain yield per plant with number of capsule per plant, plant height, number of node on main stem and seed weight per capsule was significant and positive. In uni-lateral sesame genotypes, correlation between grain yield with a number of capsules per plant, seed weight per capsule, 100-seed weight was positive and significant, but the correlation of this character with the first fruiting node height was negative and significant. In multi-lateral sesame genotypes, the grain yield per plant had a positive and significant correlation with the number of capsules per plant, plant height; the number of nodes on the main stem and lateral stems, as well as this character had a negative and significant correlation with the number of primary branches. Stepwise regression analysis for grain yield per plant in unilateral and multi-lateral sesame genotypes showed that the number of capsules per plant is the most important grain yield component.

In order to calculate the effects of using treated municipal wastewater on some physiological growth index of maize, an experiment was conducted in 2003, on an experimental farm in Isfahan South Treatment Plant. The experimental was designed with 5 treatments and 3 replications based on Randomize Completed Blocks. The treatments were, furrow irrigation with normal water (T1), surface drip irrigation with wastewater (T2), subsurface drip irrigation with wastewater at 15 cm depth (T3), subsurface drip irrigation with wastewater at 30 cm depth (T4) and furrow irrigation with wastewater (T5). The results indicated that, T4 had maximum leaf area index and total dry weight compared to other treatments with significant difference at 5% level. In addition, T3 had a higher value of the above parameters after T4 without significant difference compared to T2 and T5. On the other hand, T1 had shown minimum leaf area index and total dry weight. But because of the higher leaf area efficiency of light usage, in the maximum leaf area index stage, T1 had the highest net assimilation rate. In conclusion, application of treated municipal wastewater caused better yield growth compared to well water. Also, because of the better soil moisture and nutrient available at the root zone, application of wastewater with subsurface drip irrigation system at 30 cm depth, showed the highest yield growth rate.

Vegetation cover as a dynamic and most important factor on human living conditions should be monitored spatially and temporarily. Satellite data could be useful for environmental decision – making, particularly in specific conditions such as drought mitigation. Satellite data provide appropriate information for evaluation, monitoring and controlling of environmental activities so that environmental issues permanently could be analyzed for forecasting aims (based on predictor model resulting from studying the effective factor over the past time). In this research, different remote sensing techniques had been used for detection of vegetation change detection during 1990-1999 in Isfahan (Iran). Drought effects on vegetation canopy cover had been studied as well. Radiometric and geometric correction applied to the satellite data. Different processing techniques have been analyzed to enhance the vegetation cover. The most appropriate methods were selected for each date and the regression analysis was applied between the vegetation indexes images and field data. The results showed that the remote sensing vegetation indexes to canopy cover studies and monitoring could be efficient.

This study was carried out to investigate the effect of using subsoiler for conventional tillage on some soil properties and sunflower yield. The research was carried out in Mahyar Region (30km South) in 2002. The experiments were performed using complete randomized block design with three replications. The treatment comprised 1) conventional tillage at depth of 20-25 cm + flat planting (T1), 2) conventional tillage at depth of 20-25 cm + furrow planting (T2) and 3- sub soiling at depth of 40-45 cm + conventional tillage in depth of 20-25 cm + flat planting (T3). The cone index, bulk density, infiltration rate, root length, seed yield, plant dry weight and oil content were measured. The results indicated that there was no significant treatment difference in the bulk density and infiltration rate. The cone index was smaller in T2 and T3 in 10-20 and at 20-30 cm of depth. The results showed that the oil content in T2 was significantly lower than other treatments. The sub soiling with high cost did not affect the sunflower yield so that it is not recommended to use.

In order to study the effect of plant density on morphological and physiological characteristics in four cultivars of durum wheat (Triticum turgidum var. durum) under dryland, a field experiment was conducted in Sarableh Agriculture Research Station of Ilam province during 1998-99 year. The experiment was factorial design based on RCB (Randomized complete) with four replications. The factors were cultivars (Chalavandi Saymareh, Aconchi and Chenalter) and plant densities (300, 350, 400 and 450 plants/m2). Therefore, the effect of plant density and cultivars on morphplogical and physiological characteristics such as, stem length, spike length, peduncle length, peduncle diameter, leaf area index, flag leaf area, dry matter cumulative, tiller process, yield and yield components, biological yield and harvest index, were evaluated. The results showed that cultivar and plant density effects were not significant for grain yield, biological yield and harvest index. There was a significant difference between cultivars related to yield components, stem length and peduncle length. The results showed that the plant density effects were significant for yield components, spike length and peduncle diameter, but the Interaction effects only for 1000-grain weight were significant. Chalavandi cultivar at 300 plants/m2 with 38.2gr and Aconchi at 450 plants/m2 with 27.7 gr were given the highest and lowest 1000 grain weight respectively. Regarding comparison of the means using Duncan's approach, the highest Grain yield for Chenaltar cultivar with 1317 kg/ha and lowest the density of 350 plants/m2 with 1347 kg/ha were obtained.

Considering the culture of corn in a vast area of Fasa farms and the importance of the application of nitrogen fertilizer and the fact that most farmers apply this fertilizer to corn without knowing the needs of this plant, and finally the fact that the overdose of this fertilizer has bad biological and environmental effects and makes the land salty, in June 2004 a research project was launched on the best time to apply nitrogen fertilizer on corn on the test farm of IAUFB. In this project three methods were tested: spraying, banding fertilizer, fertigation; based on three time schedules: one, one and a half and two months after cultivation. The test was replicated three times in a factorial experiment and in a randomized complete block design. It became clear that the fertilizer is really effective in the very early stages of growth; that is, the first 25 to 75 days of growth. In pervious experiments the same results were observed. The N.P.K elements were more effective in this stage that is one two months after culture. It also became known that culture had the best effect on the third stage, that is, two months after culture and the best method was spraying because the plant can use it more easily.

In dry area, such as IRAN, where have low precipitation and high evaporation, salt accumulation on soil surface is unavoidable. Therefore it is necessary to use an applicable method for estimation of the water requirement for agricultural soil improvement. The aim of this research was drawing desalinization and dealkalization curves and applying the best type of empirical leaching models for leaching salt and sodium of south east Khoozestan province. This research has down in two areas of Khoozestan state. For this propose, two experimental areas were selected and four treatments with three replications were designed. The treatments were included 25cm, 50cm, 75cm and 100cm water application. In addition of above treatments, in second area about mention treatments were repeated by amendment matter (sulfuric acid). Eleven empirical models were compared by using initial and final values of EC and Na. The results showed that manner model was the best models with 83 and 85 percent coefficient correlation in pilot No.1. Mean while in pilot No.2 the cubic model was the best model with 94 and 88 percent coefficient correlation. In this pilot when it used acid, the exponential growth, logistic, compound and inverse models with 88% coefficient correlation, had shown upper correlation.