农作物缺少某种营养元素,容易引起缺素症。如水稻缺磷或缺钾,就易患缺磷型或缺钾型赤枯病;玉米缺锌会产生干叶病;甘蓝型油菜缺硼,则会出现花而不实症状。对于这类生理病害,必须首先弄清致病的原因,然后才能按照“对症下肥”的原则,把农作物所缺乏的某种肥料,配成适宜浓度 Crops lack a nutrient element, easily lead to deficiency. Such as lack of phosphorus or potassium deficiency, susceptible to phosphorus deficiency or deficiency of potassium deficiency; maize zinc deficiency will produce dry leaf disease; Brassica napus lack of boron, there will be flowers without real symptoms. For such physiological diseases, we must first understand the causes of disease, and then in accordance with the principle of “right under the fat,” some of the crops lacking fertilizer, dubbed the appropriate concentration