African Journal of Agricultural Research Vol. 6(5), pp. 1134-1140, 4 March, 2011 Available online at http://www.academicjournals.org/AJAR ISSN 1991-637X ©2011 Academic Journals Full Length Research Paper Agronomic and morphologic analysis of Fenugreek (Trigonella foenum-graecum L.) under nitrogen fertilizer and plant density via factor analysis P. Zandi 1 *, A. H. Shirani– Rad 1 , J. Daneshian 1 and L. Bazrkar– Khatibani 2 1 Department of Agronomy, Faculty of Agriculture, Islamic Azad University, Takestan Branch, Iran. 2 Department of Agronomy and Plant Breeding, Mazandaran University, Sari, Iran. Accepted 31 January, 2011 In order to study agronomic and morphological traits in fenugreek (Trigonella foenum-graecum L.) under nitrogen fertilizer and plant density, a field experiment was conducted at Guilan region (North of Iran) during 2008 to 2009 using split plots based on randomized complete block design with 4 replications. Four levels of nitrogen (0, 25, 50 and 75 kg/ha) as the main factor and four levels of plant density (60, 80, 100 and 120 plants/m 2 ) as sub-plots were investigated. The maximum seed yield (1468 kg/ha) produced by using 75 kg N/ha. The seed yield had the highest correlation with biological yield. The maximum biological yield was obtained from N 4 (6336 Kg/ha) and D 4 (6227 Kg/ha), respectively. Factor analysis of data after varimax rotation indicated four factors that accounted for 80.924% of total variance. The scatter plot of treatments based on the two first factors (characteristics of reproductive organ factor- height and yield factor) showed that N 3 D 3 had the desirable seed yield and N 4 D 4 had the desirable forage yield. Key words: (Trigonella foenum-graecum L.), nitrogen fertilizer, plant density, correlation, factor analysis, scatter plot INTRODUCTION Fenugreek (Trigonella foenum-graecum L.) is an annual, self-pollinated plant from Leguminosae family with small seeds and since ancient times has always been known as a medicinal herb (Slinkard, 2006). Fenugreek seeds have anti-diabetes and cholesterol-reducing properties. Moreover, the plant is known for treating gastric ulcers and its antibacterial, anthelminitic, contraceptive, and anodyne properties as well (Petropoulos, 2002). Its leaves broadly are consumed as leafy green vegetables in India and are rich in calcium, iron, carotene B and other vitamins (Sharma, 1986). Fenugreek seeds are rich in protein, fixed oils and minerals; thus, it is quite nutri- tious. Fenugreek protein is also rich in lysine amino acid and in terms of supplying the protein requirements of the human body is the same as soybean protein (Hidvegi et al., 1984). Duke (1986) reported that this plant increased *Corresponding author. E-mail: z_rice_b@yahoo.com. Tel: 00989375836734. the milk flow in cows, but impacts its aroma. An extract from fenugreek seed is usually added to fodder in order to improve animal’s palatability (Smith, 1982). Generally, nitrogen fertilizers have a major effect on stem formation, foliation and germination of plants and as a whole; it accelerates their vegetative growth (Omid-beigi, 2007). Using nitrogen in fenugreek leads to growth increase, delayed maturation, producing desired leaves, developed stem and the plant’s dark-green color which indicates a desired growth. Also, plant density on the rows affects the yield and is controlled by the amount of seeds. The appropriate spacing on the row and within the rows depend mainly upon on soil texture, depth of sowing, fertility, available moisture, temperature and the type of cultivar (Petropoulos, 2002). Identifying traits that are highly correlative with seed yield, have high heritability and are measured easily at low costs are important to breeders. Thus, they use these traits as selection criteria for yield improvement (Gurbuz et al. 2000). In China, Zhao et al. (1991) in their factor analysis of twelve main agronomical traits in 16 soybean