تاﺛﯿﺮ ﺳﻄﻮح ﻣﺨﺘﻠﻒ ﺗﺮاﮐﻢ و ﻧﯿﺘﺮوژن ﺑﺮﻋﻤﻠﮑﺮد دانه ﻓﯿﻠﻮﮐﺮون و ﺳﺮﻋﺖ ﻇﻬﻮر ﺑﺮگ ددو رﻗﻢ آﻓﺘﺎﺑﮕﺮدان

Effect of different levels of nitrogen fertilizer and plant density on yield, phylochron and leaf appearance rate of sunflower cultivars