Critical Period of Weed Competition in Spring Sunflower (Heliunthus annuus L.)

Department of Agronomy, G B. Pant University of Agriculture and Technology, Pantnagar-263 145 (Uttaranchal), India.

¹ Department of Agronomy, Bhimrao Ambedkar University of Agriculture & Technology, Modipuram, Meerut (U. P.), India.