Smoke discharge point should be noted: the use of smoke law should grasp the movement of airflow. When the ground temperature is higher than the air temperature will produce an updraft. Sunny day sun light shines on the ground greenhouse smoke, the ground temperature Zhejiang greenhouse smoke, so daytime updrafts very significant greenhouse Zhoukou smoke, especially in the afternoon. When the ground is no longer in the evening sunlight, the ground began to heat greenhouses Xinxiang smoke and emit heat is absorbed by the upper air, so this time there has been ground temperature is lower than the upper air temperatures phenomenon known as "inversion" phenomenon. Smoke also known as fumigants, aerosols. Before using aerosol pest and disease prevention in the greenhouse to check the good Roof, make up a good loophole, so Roof closed tightly, more tightly control effect better. Time in the evening with aerosol Gallant Lianhou ignite as appropriate. In cloudy, light snow in the evening aerosol pest control and disease prevention is best. This is because in the sunlight, the plant surface temperatures are the same temperature in smoke particles, smoke less deposit and affect the efficacy.