Evaluation of Growth Characteristics and Seedling Vigor in Two ...

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ABSTRACT: Soybean seed quality is defined as the attributes that will determine the performance of seeds when sown or stored. In this research using a drying ...
International Journal of Agriculture and Crop Sciences. Available online at www.ijagcs.com IJACS/2013/5-21/2537-2544. ISSN 2227-670X ©2013 IJACS Journal

Evaluation of Growth Characteristics and Seedling Vigor in Two Cultivars of Soybean dried under different Temperature and Fluidized bed dryer Samira Afrakhteh1, Esfandiar Frahmandfar2, Aidin Hamidi3 and Hadi Darzi Ramandi4* 1. Graduated MSc. of Agronomy, Crop Sciences Faculty, Sari Agricultural Sciences and Natural Resources University, Sari, Iran 2. Assistant Professor, Crop Sciences Faculty, Sari Agricultural Sciences and Natural Resources University, Sari, Iran 3. Assistant Professor, Seed and Plant Certification and Registration Institute, Karaj, Iran 4. Young Researchers Club, Takestan Branch, Islamic Azad University, Takestan, Iran. *Corresponding Author email: [email protected] ABSTRACT: Soybean seed quality is defined as the attributes that will determine the performance of seeds when sown or stored. In this research using a drying system with the fluidized bed, effect of temperature and seed bed changes on the seed quality characteristics associated with seed vigor two cultivars of soybean were studied. Therefore, harvested seeds after conditioning, by a batch fluidized bed seed dryer at 30, 40, 50 and 60°C temperatures and three seed bed situations in dryer: constant seed drying bed situation, fluidizing threshold and fluidized to standard seed moisture content (about 12%) were dried. Test germination and seed vigor tests using of ISTA methods were conducted for assess of seed quality seed and seedlings. The growth characteristics and seedling vigor in standard germination test data were determined in laboratory. The growth characteristics in the samples dried in fluidized bed drying is greater compared to those dried under constant seed drying bed situation. The results show that the decrease of the growth characteristics and seedling vigor are associated to conditions that lead to a high drying rate. Germination and vigor reduction is also associated to the over drying conditions. In this experiment, the lowest percentage of germination, length and weight index of seed vigor and other characteristics at 50 and 60 °C in a fluidized bed was and at 30 °C and 40 °C in a fluidized bed threshold the bed, most of the characters were. In both experiments the Katool cultivar toward Sari cultivar figures showed more resistance than it is probably due to genetic characteristics. Keywords: Soybean; Fluidized bed; Drying temperatures; Seed quality; seedling vigor. INTRODUCTION Soybean (Glycine max (L.) Merr.) is the most important oilseed in the world due to its high quality as a source of protein for human and animal diets (Rafiee et al., 2009). The importance of soybean in grain production has been increasing due to its high yield capacity and its lower harvest cost in comparison to other grains (Duarte et al., 2004). Also World soybean production has been continuously increasing at a remarkable rate for the last several decades; it reached ca. 265 million tons in 2010 from ca. 30 million tons in 1970 (FAO, 2012). In Iran, the area planted with soybean is 115,000 ha producing 209,000 t with an average yield of 2.4 t/ha (Anonymous, 2008). Seed quality has direct influences on the success of the crop and contributes significantly to productivity levels (Bewley and Black, 1994). The quality of soybean seeds, incidentally, can be influenced by several factors during drying (Marcos Filho and Mcdonald, 1998). Seed quality is defined as the attributes that will determine the performance of seeds when sown or stored (George, 1999). Drying of oilseeds is necessary to bring down the moisture content of harvested seeds to a safe desired level for storage and further processing. Soybean is harvested typically at moisture contents in the range 25±33% dry basis. Safe storage requires rapid decrease in moisture to preserve quality (Soponronnarit et al., 2001). During hot months, weather conditions are usually such that field drying is sufficient to reduce soybean MC to a safe level of about 13-14%, for storage. Soybeans to be stored for 50˚C) is the splitting of the seed coat. This condition makes the beans susceptible to microbial attack in storage and reduces their germination potential (Barrozo et al., 2006). Low seed moisture,