Can the side effects of using pesticides on flowers be avoided?

Pests and diseases on flowers are not like ordinary ones; in a short period of time, chemical pesticides need to be used for effective control, otherwise unpredictable consequences will result. But along with this come the side effects of pesticides on flowers. When using pesticides, as long as the following phenomena do not occur, the side effects of pesticides can actually still be avoided.

1. Randomly mixing pesticides: When flower diseases and insect pests occur at the same time, people usually mix insecticides and other agents, using two or three kinds of chemicals, and some even add foliar fertilizer. If the properties of several pesticides are the same and their pH values are close, no chemical reaction will occur, and there will be little effect on the efficacy; otherwise, it will affect the effectiveness of the pesticide and may also cause phytotoxicity. For example, Bordeaux mixture is a suspension made from copper sulfate, quicklime and water. It can control many kinds of diseases. Its liquid is alkaline and cannot be mixed with commonly used pesticides, nor can it be mixed with lime sulfur or resin agents, otherwise it will reduce the efficacy and cause phytotoxicity. Therefore, when mixing pesticides, you must first understand their pharmacological characteristics. Those that can be mixed should be mixed, and those that cannot be mixed must be used separately.

2. Improper spraying time and methods: The spraying cycle is too short. At different stages of pest and disease occurrence, the length of the pesticide spraying cycle varies. Generally, once every half month in the initial stage and once a week at the peak stage. In reality, many pests are difficult to kill and pathogens are difficult to eradicate, so some flower growers use pesticides frequently, some once every 3 days, and some even once a day. As a result, the pests are not killed, the disease is not eradicated, and phytotoxicity appears in flower seedlings. In this situation, the spraying cycle must be strictly controlled, otherwise phytotoxicity is harder to treat than pests and diseases. During control, attention should be paid to alternating the use of pesticides to prevent pests and pathogens from developing resistance, which would lead to frequent application and ultimately cause phytotoxicity. When some flower growers spray pesticides, they do not spray the pesticide onto the key parts, and sometimes they linger too long on a certain part, causing a large amount of pesticide solution to remain on the leaf surface and resulting in phytotoxicity to flowers. This phenomenon is especially obvious on old leaves and large leaves.

3. Non-standard pesticide preparation procedures: There are many dosage forms of chemical agents, including wettable powders, emulsions, tablets, granules, solutions, and so on. Some of these dosage forms can dissolve directly, while others cannot dissolve completely. Undissolved particles suspended in the solution can easily clog the nozzle during spraying. Even if smaller particles are sprayed out from the nozzle, they remain on the leaf surface, causing localized phytotoxicity to the plant. Therefore, when preparing pesticides, attention should be paid to strictly following the procedures. Pesticides of different dosage forms should first be dissolved in a small container, then transferred to a large container, and only after they are completely dissolved or evenly melted should they be transferred to the sprayer.

4. The sprayer is not cleaned and has other residues: In actual operation, flower growers often use a certain sprayer as a general-purpose tool. Sometimes after using it to apply one type of pesticide, they put another type of pesticide into it without cleaning it. As a result, the original pesticide residue causes phytotoxicity to flowers, especially residues of pesticides such as herbicides, which are even more harmful to flowers.

5. Flower allergies have proven that some flowers are allergic to certain specific pesticides. For example, cockscomb and Chinese rose are quite sensitive to dichlorvos, and chrysanthemum is sensitive to dimethoate emulsifiable concentrate diluted below 1500 times. Even when the concentration is not high and the operation is very standard, phytotoxicity still occurs. There are currently no rules to follow regarding flower allergies, and they can only be explored through practice. This requires that when applying a pesticide you are not very familiar with, you should first conduct a phytotoxicity experiment, so as to reduce the occurrence of phytotoxicity. When applying pesticides, you should first conduct a phytotoxicity experiment, so as to reduce the occurrence of phytotoxicity.