Effect of Nitrogen and Potassium on Yield, Yield Components and Essential Oil of Black Caraway (Bunium Persicum L.)

Abstract

Fertilization is the main factor stimulating yield of plants, nitrogen and potassium are among must important essential nutrients. An experiment was conducted to investigate the effect of different rates of nitrogen and potassium on yield and yield components of Black caraway (Bunium persicum L.). The experiment  was on the  base of randomized complete block design with three replications  for 3 years in Torogh agriculture and natural resources research station, iran. Plow, disc, leveling, creating planted rows and making plots was performed in mid-September. All potassium fertilizer and half of the nitrogen were applied at planting. The rest of the nitrogen was applied in the form of top-dressing at flowering stage in the second week of April. The size of each experimental plot was 4 × 3 meters in 6 rows and 12 lines.    Treatments were 4 levels of nitrogen (0,40,80and120 kgN/ha in the form of urea), and three levels of potassium (0, 40 and 80 kg k₂O/ha in the form of sop). The results showed that the effect of nitrogen and potassium on grain yield, yield components, straw yield and essential oil content was significant (P<0.05). Nitrogen rate of 40 kg/ha increased grain yield and some yield components and essential oil. Whereas the higher rate decreases grain yield and yield components, and increases  straw yield. Interaction of nitrogen and potassium on grain yield, straw yield and number of umbels per plant, was significant(P<0.05).