Matters needing attention in the application of orchids

Temperature: the active components of biological pesticides are composed of protein crystals and living spores, which must be controlled above the ideal 20 ℃. Once the spores are sprayed below the above temperature, the propagation speed of spores in the pest will be very slow, and protein crystals are difficult to play their role, and the control effect is often not shown after spraying. According to the experiment, the insecticidal effect of spraying biological pesticide at the temperature of 25-30 ℃ is 1-2 times higher than that of spraying biological pesticide at the temperature of 10-15 ℃.

Environment: the higher the humidity, the more effective the spraying of biological pesticides, especially the powdered biological pesticide preparations. It is best to spray bacterial powder when there is dew sooner or later, so that the agent can adhere to the stems and leaves of the orchid, so that the spores propagate quickly.

Sunlight: ultraviolet rays in the sun have a deadly effect on spores. Scientific experiments show that the mortality rate of spores can reach 50% in only 30 minutes under the direct exposure of intense sunlight. After 1 hour of irradiation, the death rate of spores is 80% higher, and ultraviolet radiation can deform parasporal crystals and reduce the efficiency. Therefore, choose to apply biological pesticides after 16:00 or on cloudy days, the efficacy will be better.

Rain Water: the torrential rain will wash away the biological pesticides sprayed, making the spores lose their lethality. However, if there is light rain for five or six hours after spraying, the efficacy will not be reduced, but will be improved. Because light rain is very beneficial to the reproduction of spores, it can kill more pests.

Look at the wind; the application of bacterial pesticides in windy days is wasteful, especially the powder, which loses more. At the same time, windy days are not conducive to spore germination. Therefore, bacterial pesticides should be applied on windless or breezy days.