今年夏季我国北方地区气温偏高，据气象部门报道是近百年来罕见的高温年份。因此对西芹的生长极为不利，造成了各种生理方面的障碍，主要表现在：①幼苗期生长点被高温灼伤后产生了分蘖，生长点栓（钝）化，不发棵；②高温、强光使植株横向发展，抑制纵向伸长，开展度增大；③? This summer, the temperatures in northern China were high, and according to the meteorological department reports, it was a rare high-temperature year in nearly a hundred years. Therefore, the growth of celery is extremely unfavorable, resulting in a variety of physiological obstacles, mainly in: ① seedling growth point after being burned by high temperature produced tillering, the growth point of the plug (blunt), does not send trees; ② high temperature, Glare makes the horizontal development of plants, inhibition of longitudinal elongation, increased degree of development; ③?