What are the main pests and diseases of summer flowers? A full analysis of control methods
According to a recent survey, there are currently many kinds of flower pests and diseases, with diseases occurring rather severely. The main pests and diseases occurring include: whiteflies, American serpentine leafminer, scale insects, scarab beetles, chrysanthemum black spot, anthracnose, and so on.
Whiteflies
This pest occurs on many kinds of flowers, with poinsettia suffering the most severe damage. In recent surveys in Hualong, Panyu, Zhenglong, Zengcheng, Fangcun and other places, relatively large numbers of the pest were found on poinsettia, African daisy, Nephrolepis, Ludi, cineraria and other varieties, with an average of 268.7 live insects per 100 plants, among which poinsettia and African daisy had 300-403 live insects per 100 leaves. The nymph stage is predominant, which is also the appropriate period for control. This pest has the characteristics of rapid reproduction, overlapping generations, and strong pesticide resistance, so pesticide application must be timed to the nymph stage to improve control effectiveness.
American serpentine leafminer
This pest is a major pest of chrysanthemum, dahlia and other flowers. In a recent survey, the average leaf damage rate was 13.6%, with 28 live insects per 100 leaves, and a pest index of 3.2. This pest is expected to occur at a moderate level.
Scale insects
At present, the population density on areca palm, small-leaved banyan and sago palm is relatively high. The scale insect species occurring include: armored scales, cottony cushion scale, wax scales, etc. The leaf damage rate was 7.8%, with 929.3 live insects per 100 leaves, and in some severe cases as many as 4878.
Scarab beetles
This pest is polyphagous; the adults gnaw leaves and petals, while the nymphs damage the roots. According to a recent survey of chrysanthemum, velvet plant, Ludi, areca palm and others, the leaf damage rate was 5%, with 2--6 live insects per 100 plants.
Chrysanthemum black spot
The recent weather has been quite humid, which very easily induces the occurrence and development of this disease. According to a recent survey of chrysanthemum varieties such as Lijin and Anning Princess, black spot occurred rather severely, with a plant incidence rate of 27.8%, up to 43% in severe cases, and a leaf incidence rate of 13.4%.
Anthracnose
This disease occurs on African daisy, chrysanthemum, Hawaiian coconut palm, peace lily, and lucky coconut palm and other flowers, with a general plant incidence rate of 20.25%, a leaf incidence rate of 14.5%, and up to 61% in severe cases.
In addition, some flowers are damaged by thrips and red spider mites; African daisy had [number missing in source] live thrips per 100 plants, and small-leaved banyan had 60 live insects per 100 plants.
Control methods
1. To control flower whiteflies and scale insects, pesticide application should be timed to the peak nymph period.
Whiteflies: choose 10% Confidor 2000 times, or 2% diflubenzuron 2000 times, or 10% imidacloprid, or Dichlorvos-plus-aphid-and-whitefly-killer 1000 times solution for spraying. Spray once every 7--10 days, for 2--3 consecutive sprays.
Scale insects: choose 40% Supracide, or Sujieke 1000-1500 times, or 40% omethoate and others at 1000 times solution for spraying.
American serpentine leafminer: 1.8% Abamectin, or Lvcaibao 1000--1500 times, or 40% Lorsban 800 times solution for spraying.
2. To control flower diseases, start applying pesticide at the seedling stage or early stage of disease onset, and depending on the severity, spray once every 7-15 days, for 3-5 consecutive sprays.
Chrysanthemum black spot: (1) Remove old diseased leaves and burn them in a centralized manner; (2) Chemical control: choose 50% carbendazim 500 times, or 80% captafol 800 times, or 25% propiconazole 1000---1500 times solution for spraying.
Anthracnose: choose 50% Shibaogong 1000 times, or 40% Shibaole 1500 times, or 75% chlorothalonil + 70% thiophanate-methyl 1000 times solution for spraying.