فهرست مطالب میرناصر سیدی

In order to study the effects of seed inoculation with rhizobium and nitrogen application on yield and some agronomic characterstics of soybean (Glycine max L.), a spilt plot experiment based on randomized complete block design with three replications was conducted in 2011 at the research farm of the Islamic Azad University, Ardabil Branch. Factors were inorganic nitrogen fertilizer urea at four levels (0, 30, 60 and 90 kg urea/ha) in the main plot and two levels of inoculation with Rhizobium japanicum bacteria (with and without inoculation) assigned to the sub plots. Study the growth indices showed that the maximum total dry matter (435.4 gr/m2), crop growth rate (6.75 gr/m2.day) and relative growth rate (0.1003 gr/gr.day) were obtained from compound of treatments high levels of urea application × inoculation with rhizobium while, the minimum values of these indices recorded in without nitrogen application×non inoculation with rhizobium. The highest plant height, number of pod per plant and grain yield were obtained from the highest level of nitrogen fertilizer (90 kg/ha urea) and seed inoculation with rhizobium. Number and dry weight of nodules per plant increased significantly with increasing nitrogen application till 60 kg/ha in seed inoculation with rhizobium. The lowest values of these traits recorded in non application of urea×non inoculation with rhizobium. Inoculation with rhizobium bacteria increased the number and dry weight of nodules per plant. Thus, it can be suggested that in order to increasing of grain yield, seed can be inoculated with rhizobium bacteria × application of 60 kg urea/ha in conditions of Ardabil region.

To evaluate the effect of various levels of nitrogen fertilizer on nitrogen use efficiency and grain yield of canola cultivars, a split plot experiment based on randomized complete block design was conducted in 2007. Factors were: nitrogen fertilizer at four levels (zero, 50, 100 and 150 kg/ha) in the main plots and canola cultivars at three levels (‘Clover’, ‘Opera’ and ‘Okape’) in the sub plots. The results showed that the effects of cultivar and nitrogen levels were significant on grain yield, grain per plant, pod per plant, grain 1000 weight, harvest index and plant height. The interaction effects of cultivars in nitrogen levels were significant on grain yield, grain per plant, pod per plant and plant height. Means comparison showed that with increasing nitrogen levels, grain yield increasing. Response of canola cultivars was different to grain yield. The highest grain yield (1.18 ton/ha) was obtained in Opera cultivar and the least (0.78 ton/ha) of it was in Okape cultivar. Means comparison showed that the highest grain yield, grain per plant, pod per plant and plant height was obtained by the plots which applied 150 kg N/ha with Opera cultivar and the least of it was in Okape cultivar without nitrogen application. However, application of 100 and 150 kg N/ha had similar grain yield in Opera cultivar. Nitrogen use efficiency was significantly as affected by cultivar, nitrogen levels and cultivar × nitrogen levels. Means comparison showed that with increasing of nitrogen, decreased nitrogen use efficiency. Response of canola cultivars was different with nitrogen use efficiency. Maximum nitrogen use efficiency (5.26 kg/kg) was obtained in the plots which 100 kg nitrogen ha-1 with Opera cultivar was used and minimum (2.64 kg/kg) was obtained in the plots which 150 kg nitrogen ha-1 with okape cultivar was used.

In order to comparison of the best seed vigor test for predicting of seedling emergence as well as their relationship with grain yield in rapeseed, a study was conducted using 9 rapeseed cultivars (Option500, Excell, PF7045.91, Peace, Cyclone, Quantum, Q2, Golliath and Hyola401). Laboratorial tests such as germination, seed deterioration and seedling growth tests were carried out using completely randomized design and field experiment as randomized complete blocks in Agricultural Science and Natural Resources at Gorgan University in 2004–2005. The results showed that germination velocity (germination test) had the highest relationship with seedling emergence in field and the equation estimated 84% of variation in prediction of seedling emergence using linear regression. The results obtained from variable option in the mode of stepwise procedure showed that only germination velocity at germination test had significant effect in prediction of seedling emergence in field. Thus this factor can be used for prediction of rapeseed seedling emergence in field. The results also showed that the correlation between seed vigor (rapid, uniformity and germination percentage) with grain yield was not significant when optimum plant density was present in the field.