上海地区,每年四月中旬至五月中旬,正当三麦抽穗扬花、灌浆乳熟的时候,刚好是春雨最多的季节。这时温度逐渐回升,平均气温一般在14～18℃,平均雨日18天,雨量133毫米,春雨多的年份达200毫米以上。这一段时间高温高温天气较多,是上海郊区赤霉病的主要流行期。奉贤县19年的观察资料表明,元大麦的始病期大都发生在四月中下旬,盛发期在四月下旬后期至五月上旬;小麦的始病期在四月下旬至五月上旬,盛发 Shanghai region, mid-April to mid-May each year, just when the three wheat heading and flowering, filling milk cooked, just happens to be the most spring season. At this time the temperature gradually rose, the average temperature is generally 14 ~ 18 ℃, the average rainfall day 18 days, the rainfall of 133 mm, the spring of more than 200 mm in the year. This period of high temperature and temperature weather is more, is the main epidemic of Shanghai suburbs scab. Fengxian County, 19 years of observation data show that most of the malformations of barley occurred in late April, Shengfa period from late April to early May; the onset of wheat in late April to early May, Sheng hair