What to Do About Flower Pests and Diseases in Autumn? Occurrence Patterns and Control Methods
The main types of flower pests and diseases in autumn include: leaf spot disease, black spot disease, anthracnose, wilt disease, powdery mildew, scale insects, aphids, thrips, longhorn beetles, carpenter moths, whiteflies, leafminers, mites (red spider mites, tarsonemid mites), nematodes, and others.
Leaf spot disease mainly damages camellia, osmanthus, elm, orchids, bromeliads, Buddhist pine (Podocarpus macrophyllus), areca palms, and others. Generally, the diseased leaf rate is 15%-30%, and in severe cases it reaches over 50%.
Black spot disease mainly damages Chinese rose, rose, chrysanthemum, and others. Flowers are commonly affected, with a damage rate generally of 20%-40%.
Anthracnose affects many flower species. Common affected flowers include orchids, lucky bamboo (Dracaena sanderiana), camellia, Aglaia odorata, orange jasmine (Murraya paniculata), rubber tree (Ficus elastica), Michelia alba, clivia, Calathea species, and palm family flowers. The leaf damage rate of flowers is 10%-30%, and in severe cases over 90%.
In addition, powdery mildew damages crape myrtle, Chinese peony, and others, while wilt disease damages palm family flowers (seedling stage), chrysanthemums, and others.
Scale insects are a relatively common pest, often damaging sago palm (Cycas revoluta), areca palms, Michelia alba, osmanthus, camellia, Michelia figo, orange jasmine, banyan, elm, Fujian tea (Carmona retusa), and bamboo palms. They occur heavily in environments with high planting density and high shade levels. If not controlled in time, they can easily cause leaf drop, dead branches, and even plant death.
Mites damage many flower species. Common ones include citrus species, elm, marigold, Chinese rose, rose, sago palm, and bamboo species. Autumn is the peak period for mite damage, and targeted pesticides must be used for timely control.
In addition, thrips often damage small-leaved banyan and others. Longhorn beetles and carpenter moths bore into the thick branches and trunks of transplanted banyan, Heteropanax fragrans, sago palm, and others, with a general damage rate of 10%-40%. Whiteflies, aphids, and leafminers mainly damage chrysanthemums, Chinese peonies, azaleas, and similar flowers. Nematodes occur commonly and are not easily detected. Their main targets include lucky bamboo, palm family species, chrysanthemums, and others.
Flower pest and disease control should focus on prevention, and it is especially important to consider how to avoid polluted water sources that lead to disease outbreaks. In addition, pesticides must be matched to the specific problem and applied promptly.
1. In the flower field, promptly clean up diseased and dead branches and leaves, use clean water sources to irrigate flowers, and rationally arrange the planting layout of flower varieties in the field to reduce repeated infection and mutual spread of pest and disease sources.
2. Match pesticides to the specific problem and apply them promptly for control.
Disease control: For leaf spot disease and black spot disease, pesticides such as thiophanate, carbendazim, mancozeb, and copper oxychloride can be used for control. For anthracnose, use prochloraz, Sportak, or zineb for control. For powdery mildew, use fenarimol, suspension concentrate, or triadimefon for control.
Pest control: For scale insects, it is advisable to use methidathion and omethoate for control. For mites, use pyridaben, propargite, amitraz, and others for control. For thrips and whiteflies, use imidacloprid, rice planthopper pesticide, and methomyl for control. For leafminers, use dimehypo, cartap, and others for control. For nematodes, use carbofuran and milbemectin for control. If boring pests occur, in addition to surface spraying of pesticides, methods such as pesticide injection and mud paste application can also be used for control.