夏季高温期不同覆盖物对棚内小气候、蔬菜病害发生和产量的影响

2011年6~8月,在益阳市4个基地,设置4个处理,对塑料大棚内温度、光照进行了3次实地测定,调查了4个处理与对照的病害发生为害情况和产量变化.温度测定结果表明,A 处理降温最大,为4.5℃;D 处理最低,为0.5℃;B处理增温最高,达2.5℃;C处理增温最小,为0.5℃.光照测定结果表明,2个处理都降低了棚内光照强度,其中a处理降低光照强度大,最大值为2.85万lx;b处理降低光照强度小,最大值为0.98万lx.病害调查结果表明,4个处理都明显降低3种蔬菜作物主要病害的发病株率和病情指数,其中A处理下黄瓜霜霉病的发病株率和病情指数降低最大,分别达97%,0.960.产量调查结果表明,4个处理下,3种蔬菜都增产,但增产幅度有差异,其中增产率最大的是C处理的辣椒,增产57.1%;增产率较小的是A处理的黄瓜,仅增产13.5%.同时,在夏季高温期,针对喜温且要求较强光照的蔬菜,提出了蔬菜生产实施“一片白”(塑料大棚盖棚膜)的栽培模式和塑料大棚在夏季高温期只开两头大棚门和两边通风窗的降温管理技术措施.

Effects of Different Coverings on Microclimate in Plastic Greenhouse,Disease Occurrence and Yield at High-temperature Period in Summer

During June to August of 2011,we set up four treatments（treatment A,B,C,D） in four bases of Yiyang toinvestigate the temperature and light condition in the plastic greenhouse for three times,and we also investigated andcompared the disease occurrence and yield of the four treatment and control.The results of temperature measurement test showed that,treatment A and treatment D decreased the temperature by 4.5℃ and 0.5℃,while treatment B and treatment C increased the temperature by 2.5℃ and 0.5℃ respectively.The results of the light measurement test showed that,both the two treatments（treatment a,b） reduced the light intensity inside the plastic greenhouse,and treatment a and treatment b decreased the light intensity by 28 500 lx and 9 800 lx respectively.The results of the disease survey test showed that,the four treatments significantly decreased the main disease incidences and main disease indexes of the three testedvegetables,and the disease incidence and disease index of downy mildew on cucumber were reduced maximum by 97% and 0.960.The results of the yield test showed that,the yields of the three tested vegetables were increased at different degree under the four treatments,and pepper possessed the highest yield increasing rate of 57.1% under the conditions of treatment C,while cucumber had the lowest increasing rate of 13.5% under the conditions of treatment A.Thus,under the high-temperature period in summer,the treatment C was the most suitable for the growth of thermophilic and photophilous vegetables,like cucumber,pepper and cowpea.