抄録
To improve the working environment of farmers, the spray test of liquid pesticide was made in a testing greenhouse. TPN (75% wettable powder) diluted 800-fold was sprayed under the various spray conditions, and the change of aerial concentration and sticking amount to a filter paper were measured.
And the generation amount of secondary droplets which generate from the target was also measured.
The experimental results are summarized as follows.
1. The aerial concentration increased with the rise of spray pressure, and this increase greatly depended on the increase of coarse particles more than7μm.
2. The humidity in the greenhouse greatly influenced the aerial concentration. When the pesticide was sprayed in a high humidity atmosphere, the aerial concentration become smaller because of the evident decrease of respirable particles less than 7μm.
3. The sticking amount increased with the spray pressure rise.
4. The generation amount of secondary droplets increased linearly with the spray pressure rise. However, with the increase of nozzle number and low pressure spray, the generation amount could be obviously decreased without reduction of the flow rate. The generation rates of secondary droplets were 13-20%. On the basis of this result, it was proved that about 20% of pesticide sprayed in a cultivating field scatters in the air.
