1.Determine the pesticide spraying time according to the temperature and its changing trend
Whether it is a plant, an insect or a pathogen, 20-30°C, especially 25°C, is the most suitable temperature for its activity.
Spraying the medicine at this time will be more effectivefor the pests and weeds in the active period and safer for the crops.
(1) In the summer high temperature season, the spraying time should be before 10 am and after 4 pm.
(2) In the cool spring and autumn season, it should be selected after ten o'clock in the morning and before two o'clock in the afternoon.
(3) For greenhouses in winter and spring, it is best to spray medicine in the morning in sunny and warm weather.
2.Determine the spraying time according to the humidity and its changing trend
After the liquid sprayed from the nozzle is deposited on the target, it needs to be spread out to form a uniform medicinal film to cover the
surface of the target to the greatest extent, and then "mask" the pests on the target. The chemical liquid will be affected by many factors
from the deposition to the deployment, among which the air humidity is more affected.
(1) If the air humidity is low, the water in the droplets will quickly evaporate into the air, and you can't even wait for the liquid to spread on
the target. Of course, this will reduce the efficacy of the medicine and even cause burning phytotoxic spots.
(2) If the air humidity is too high, the liquid medicine deposited on the surface of the plant, especially the large fog droplets, is easy to con
dense into larger droplets, and the lower part of the plant is deposited under the secondary influence of gravity, which will also cause phyt
otoxicity.
Therefore, the spraying time of the day needs to follow two principles, one is that the air humidity is slightly dry, and the other is that the dr
ug solution can form a dry film on the surface of the target before sunset after spraying.
3.Several common illusions in spraying drugs
(1) Determine the quantity of pesticides in each bucket of water only by the dilution factor
Most people are accustomed to calculating how much pesticides are added to each bucket of water according to the dilution factor. In fact, this is not very reliable. The reason for controlling and calculating how much medicament is added to the medicine box is to calculate how much medicament is needed per unit area of plants to ensure good efficacy and safety to plants and the environment.The most reasonable measure is to choose equipment with better spray performance, or mix pesticides according to the product instructions, and spray carefully.
(2) The closer the nozzle is to the target, the better the efficacy will be
After the pesticide liquid was sprayed from the nozzle, it collided with the air and broke into smaller droplets while rushing forward. The result
of the stumble all the way was that the droplets became smaller and smaller. That is to say, within a certain distance, the farther away from th
e nozzle, the smaller the droplets. Small droplets are easier to deposit and spread on the target. Therefore, it is not to say that the spray nozzl
e will be more effective if it is close to the plant.
Generally speaking, the nozzle of the knapsack electric sprayer should be kept at a distance of 30-50 cm from the target, and the motorized sp
rayer should be kept at a distance of about 1 meter. According to the performance of the sprayer and its nozzle, swing the nozzle to let the mist
fall on On the target, the drug effect will be better.
Post time: Aug-23-2021