【摘要】 本文研究了黄瓜霜霉病发病与体内糖的成份的关系。经三年测定,黄瓜任何品种均以自上向下数第5～6节位卷须汁液可溶性固形物含量稳定。顶端高于基部;下午高于上午;灌水前高于灌水后;晴天高于阴天;采瓜前高于采瓜后。以可溶性固形物含量测定值在4以下为感病指标,可用于测定黄瓜品种对霜霉病的抗性及预测预报。 在黄瓜发病前,喷1％糖溶液可降低病情指数,防效80.3～89.5％,其中红糖>蔗糖>葡萄糖。应用1％糖溶液混1％尿素液,每隔10天喷1次,可控制病害发生。更多还原

【Abstract】 Our experiments which took us three year’s showed that these is so-me relationship between the occurrence of downy mildew and the kinds of sugar in the plant body. It Is the tendrill at 5-6th node ( from top down ) which has the most steady quantity of soluble solid-state substa-nces in the juice with any varietv of cucumber.In general there is higher density of sugar concent in the upper tendril than in the tower ones; in a day there is higher density in the afternoon than in the Morning;before irrigation the density is higher than that after it is irrigated; in a fine day the density is higher than that in a cloudy day; if some cucumber were picked the density will get lower.The degree of sugar concent under 4 has been taken as index of susceptibility, and the method of detection of sugar concent can be used to examine the ability of different cucumber to resist the disease Occur-rence and foresee the occurrence of downy mildew.The experiments showed that before a cucumber falls ill, to spray 1 % sugar water solution is helpful to lower the disease index. The eff-iciency of control may be 80.3% to 89.5%.The effects of some kinds of sugar came as : brown sugar>sucrose>glucose.Use 1 % suger solution plus 1% urea, spray once every 10 days, the occurrence of disease will be under control.更多还原