论文部分内容阅读
实践说明,大白菜适时早播能够节省用肥,促进结球,提高产量,是增产的一项重要措施。但遇有灾害性天气的年份,如1973、1980年,早播又会招致白菜病毒、霜霉和软腐病发生。因之,如何适当地安排大白菜的播期,是一个难度较大的问题。一、苗期气候灾害关中气候特点是伏旱、秋涝。伏旱多在7—8月,秋涝多在8—10月。8月是个旱涝不定,年际变化很大的月份。白菜苗期可能遇到的灾害性天气有下列四种: (一)暴雨骤晴 8月至9月上旬多雨,
Practice shows that timely sowing Chinese cabbage can save fertilizer, promote the ball, increase production is an important measure to increase production. However, in severe weather years, such as 1973 and 1980, early sowing can cause cabbage virus, downy mildew and soft rot disease. Therefore, how to arrange the sowing date of Chinese cabbage is a more difficult problem. First, the seedling climate disasters Guanzhong climate is characterized by drought, autumn floods. Volt drought in July-August, autumn and more in August-October. August is a month of droughts and floods, with a wide range of annual changes. Cabbage seedling may encounter disastrous weather has the following four kinds: (a) heavy rain sunny August to early September rainy,