Zehra Aytaç

Changes in N, K, and Fatty Acid Composition of Black Cumin Seeds Affected by Nitrogen Doses under Supplemental Potassium Application

This study was carried out to determine the efficiency of nitrogen (N) doses (0, 30, 60, and 90 kg N ha−1) under supplemental potassium (K) application (50 kg K2O ha−1) on black cumin in 2011 and 2012. The results showed that increased N levels resulted in increasing seed yield and N and K contents in seed, while oil content decreased. The seed yield and oil yield were peaked at the doses of 60 kg N ha−1 and 50 kg K ha−1. An increase in N doses caused a reduction in oil content regardless of K supply. Saturated fatty acids and oleic acid were slightly increased by K application, while minor changes in linoleic acid were detected. It was concluded that 60 kg N ha−1 with supplemental K application should be advised for enhancement in seed yield, oil yield, and N and K contents in seeds of black cumin without significant changes in fatty acid composition.

Application of the common vector approach on identification of winter rapeseed (Brassica napus L.) cultivars and their yield characters

In this study, five winter rapeseed cultivars (Ceres, Zorro, Falcon, Express, and Samourai) growing over two years were classified by using the common vector approach (CVA), Fishers linear discriminant analysis (FLDA) and support vector machine (SVM). For this purpose, seven yield characters (plant height, number of branches per plant, number of pods per plant, number of pods on main stem, number of seeds per pod, pod length and thousand seed weight) of each cultivar were used. Cultivars grown in the years 2003 and 2005 were classified separately by using seven yield characters each of which has 20 samples. Then cultivars were also classified by using seven yield characters each of which has 40 samples obtained by combining the plant samples belonging to the years 2003 and 2005. Furthermore, the seven and six yield characters taken from five cultivars grown in 2005 were classified by using only CVA. When CVA is used in all studies, 100% classification rate is guaranteed for the training set of all studies. For the test set, the classification of five cultivars has low performance, but the classification of seven and six yield characters gave satisfactory results. It is concluded that the CVA method was more successful in the classification of different varieties belonging to any plant and/or of different characters belonging to any variety.

RELATIONSHIPS BETWEEN THE SEED YIELD AND SOME AGRONOMIC CHARACTERISTICS OF SAFFLOWER (Carthamus tinctorius L.) UNDER SEMI-ARID CONDITIONS

This study was carried out in the experimental field of Faculty of Agriculture, University of Eskişehir Osmangazi, in 2009 and 2010 under semi-arid conditions. Thirteen different safflower cultivars and lines (V49/848, V-50/166, V-50/426, V-51/263, KN 144, Finch, Sahuaripa 88, Ole, AC Stirling, Oleic Leed, US 10, N 5, UC-1) were used as materials. The cultivars and lines were planted in a Randomized Complete Block Design with three replications. Significant differences (P<0.01) were found for all studied yield components. The seed yield differed significantly between 976.7 and 1666.0 kg/ha. The seed yield showed a positive and significant correlation with plant height, seed yield per plant, seed weight per head and biological yield per plant. The greatest direct effect corresponded to plant height, seed weight/head and 1000-seed weight on seed yield.