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

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