Effect of the biological and chemical fertilizers on yield, yield components and oil content of Sesame (Sesamum indiucm L.) under climate conditions of Mashhad

Sesame is a valuable oil seed crop that has lower yield and input response in comparison to other crops. Because of the less Improved genetic characteristics of sesame in comparison with dominant crops¡ and the lack of development in management methods and mechanization in sesame have resulted in neglecting cultivation of this plant (Rezvani Moghaddam et al¡ 2005; Jahan et al.¡ 2012). Several studies have presented useful effects of biological fertilizers on crop yield that¡ in addition to providing necessary nutrients for plants¡ they have lower cost and unlike chemical fertilizers do not have adverse effects on the environment. These fertilizers could therefore be helpful in the cultivation of crops such as sesame and restoring them to agricultural systems (Jahan and Nassiri Mahallati¡ 2012). The aim of this study was to investigate the effect of biological and chemical fertilizers supplying nitrogen¡ phosphorus and sulfur for the production of sesame.
An experiment was conducted based on a RCBD with three replications at the agricultural research field of Ferdowsi University of Mashhad during the 2012-2013 growing season. Ten treatments that included Nitroxin (1)¡ Biophosphor (2)¡ Biosulfur (3)¡ a double mixture of 1 and 2 (4)¡ a triple mixture of 1 and 2 and 3 (5) and chemical fertilizers of Urea (6)¡ triple super phosphate (7)¡ double mixture of 6 and 7 (8)¡ triple mixture of 6 and 7 and elemental sulfur (9) and a control (10) were applied. For all treatments¡ 20 ton ha-1 of manure was applied before planting.
The results showed that application of biological and chemical fertilizers was significant on the number of capsules per plant¡ biological yield¡ grain yield and oil yield. The number of capsules per plant was the most important component in sesame yield (r=0.87)¡ but the number of seeds per capsule¡ 1000-seed weight and harvest index were not affected by treatments. Also¡ seed oil content was not affected by the treatments¡ so the highest oil yields were gained in treatments which had produced more seeds. In treatment no.9 (multiple mixture of chemical ferilizers of urea-triple super phosphate-elemental sulfur) the biological and grain yield increased by 51.1 and 54.44 percent¡ respectively¡ in comparison to the control. Generally¡ the treatment of a multiple mixture of chemical fertilizers of urea-triple superphosphate-elemental sulfur had the highest number of capsules per plant (107 capsules)¡ biological yield (20¡908 kg ha-1)¡ grain yield (3¡757.8 kg ha-1) and oil yield (1¡674.6 kg ha-1)¡ which had no significant difference with the treatment of multiple mixture of biological fertilizer of Nitroxin-Biophosphor-Biosulfur (treatment no.5). In this experiment¡ although biological fertilizers did not affect the sesame seed oil percentage (a qualitative feature) because of such reasons as plant characteristics or ineffectiveness of effective microorganisms of biological fertilizers¡ they increased the quality of the product (oil yield) in parallel with yield.
The results showed that¡ in general¡ the use of biological fertilizers can increase both growth and yield characteristics of sesame seeds similar to chemical fertilizers. The highest yield of sesame was gained in mixed treatments of biological and chemical fertilizers. The application of these fertilizers increased leaf area index and improved the ability of plants to grow better and produce more biomass¡ thereby achieving a higher yield. In general¡ it can be said that for successful and economic production of sesame¡ in addition to chemical fertilizers bio-fertilizers can also be used. In addition¡ this offers long-term benefits such as reducing the input costs¡ greater sustainability of production and agricultural production and environmental health.