Which pesticides are prohibited or should be used with caution on flowers?

Ornamental plants such as flowers are relatively sensitive to pesticides. Improper use of pesticides can cause leaf drop, flower drop and fruit drop in mild cases, and lead to plant death in severe cases.

Dimethoate, omethoate: extremely sensitive to kiwifruit, do not use; they cause obvious phytotoxicity to Rosaceae ornamental plants such as Japanese apricot, cherry blossom, flowering peach, elm-leaved spirea, Chaenomeles speciosa, apricot and pear. The above ornamental plants should not be treated with dimethoate or omethoate.

Dichlorvos: causes obvious phytotoxicity to ornamental plants such as Japanese apricot, cherry, peach, apricot, elm-leaved spirea, Nijisseiki pear and Jingbai pear, and other types of insecticides should generally be used instead. When using pesticides to control pests on rhododendron, Salix matsudana f. umbraculifera, kiwifruit, Sophora japonica, walnut and cucurbits, great caution should be exercised.

Trichlorfon: has phytotoxic effects on cherry blossom, Japanese apricot, and the Golden Delicious variety of apple, among others.

Lime sulfur mixture: causes phytotoxicity to Rosaceae plants such as peach, plum, Japanese apricot and pear. If lime sulfur mixture is used on these plants, spray it during the leaf-drop season, and never use it during the growing season or the flowering and fruiting period.

Bordeaux mixture: sensitive for peach and plum during the growing season; when below the specified dilution multiple, pear, apricot and persimmon are prone to phytotoxicity, and when above the specified dilution multiple, grape is prone to phytotoxicity.

Petroleum emulsion: easily causes phytotoxicity to certain peach varieties; use it during the leaf-drop season.

To prevent pesticides from causing phytotoxicity to many ornamental plants, first, purposefully switch to other highly effective pesticides that cause no phytotoxicity; second, reduce the concentration used as much as possible; third, do not spray pesticides under conditions of high temperature and high humidity.