Because of continuous growth, nutrient deficiencies retard the growth of tobacco seedlings in any growth stage; however, nutrition oversupplies lead to late maturation of the leaves at mature stage, resulting in poor quality. 由于烤烟在整个生育期都保持连续生长状态,任何时期营养的缺乏都会阻碍植株的生长,但生长后期营养过多又会以抑制烤烟成熟,影响烟叶的品质。