油菜是需肥量较大的作物,常因施肥不足或施肥不当,导致植株生长发育迟缓,造成严重减产。因此平时应注意观察油菜叶片的颜色变化,掌握其发病原因,及时对症下药,挽回损失。缺氮。油菜缺氮的主要症状:甘蓝型油菜叶片变红,叶绿 Rape requires more fertilizer crops, often due to inadequate fertilizer or improper fertilization, leading to plant growth retardation, resulting in serious production cuts. So usually should pay attention to observe the color changes of rape leaves, grasp the causes of the disease, timely remedy, save the loss. Nitrogen deficiency. The main symptoms of nitrogen deficiency in rape: Brassica napus leaves turn red, green leaves