What are the common pests and diseases of lotus? A detailed explanation of prevention and control methods
1. Black spot disease:
In the early stage, irregular brown lesions appear on the leaf surface, with slight concentric rings. Later, dark black mold-like growth appears on the lesions, and several lesions often join together to form large patches. In severe cases, the entire plant dies.
Prevention and control methods:
In the early stage of the disease, promptly spray 50% carbendazim or 75% chlorothalonil at 500-800 times dilution for control.
2. Rot disease:
In the early stage of the disease, bluish wilt-colored patches appear on the leaf margins, then join together and spread inward, and finally the entire leaf turns brown. After the lotus root is affected, the central part turns brown and gradually necroses longitudinally toward the lotus root nodes and lotus stems.
Prevention and control methods:
In the early stage of the disease, spray 50% carbendazim at 500-600 times dilution for control.
3. Spodoptera litura:
Newly hatched larvae gather on the undersides of leaves and feed on the leaf mesophyll, leaving the epidermis and veins. The damaged leaves look like window screens and appear grayish-white. After the larvae grow slightly larger, they disperse to feed, biting the leaves into notches, and can also bite flower buds and flowers. Damage is most severe from June to October each year.
Prevention and control methods:
Promptly remove and destroy infested leaves. At the same time, when the larvae are gathering and causing damage, spray methamidophos at 1000 times dilution in the evening for control.
4. Aphids:
Aphids have strong adaptability to climate and are widely distributed. They mainly pierce and suck the stems and leaves of plants, especially the young and tender parts. Aphids have strong reproductive capacity and adaptability, and their population is huge, so it is very difficult for any method to achieve complete eradication.
Prevention and control methods:
It is necessary to regularly spray 80% dichlorvos emulsifiable concentrate diluted 500-1000 times.
The above is an introduction to the differences between lotus and lotus flowers, as well as pests and diseases and their prevention and control methods. To learn more, please follow Four Seasons Plants Network!
Common diseases of lotus bamboo and their prevention and control methods
Common disease of lotus bamboo: anthracnose
Symptoms of anthracnose in lotus bamboo
Anthracnose is a common disease of lotus bamboo. It occurs relatively commonly and is a serious disease harming lotus bamboo in the south. Because of the high temperatures last winter and this spring and the long period of drought, early-planted lotus bamboo in Zhanjiang, Guangzhou, Taishan and other areas of Guangdong has already grown luxuriantly. According to many flower growers, the leaf tips to leaf blades of many lotus bamboo plants have become dry and withered, and the damage has continued to spread and expand to the upper leaves. Due to the long period of drought and high temperature, the arrival of rainfall led to an outbreak of the disease. It was diagnosed as an epidemic of lotus bamboo anthracnose, and it became epidemic early in mid-March.
The disease initially mostly occurs on leaf tips, leaf margins and leaf blades. In the early stage, the affected parts show water-soaked dark green irregular lesions and gradually spread and expand to the upper leaves. In the middle stage, they are semicircular to irregular, with dark brown edges and obvious boundaries. In the later stage, the outer edges of the leaf lesions have yellow halos, and the centers of the lesions are grayish-brown or grayish-white to yellowish-brown. The concentric rings on the lesion surface are obvious or not obvious, and small black spots appear on the lesions. The leaves begin to gradually turn yellow and die. Once the lesions spread and expand to the leaves, tender leaf buds, main stems and leaf stem bases, when the disease is severe, the stems and leaves will quickly wilt and die. Under weather conditions of continuous rain and heavy fog and dew, the diseased leaves spread, the plants grow poorly, and the effect of foliage viewing is seriously affected.
Prevention and control methods for lotus bamboo anthracnose
Strengthen the care and management of lotus bamboo, and do not plant too densely. Pay attention to avoiding freezing injury and frost injury. Irrigate with moisture, fertilize reasonably, and increase the application of phosphorus and potassium fertilizers to promote growth and improve disease resistance. In winter and spring, cut off diseased leaves and clear away dead leaves, and burn them in a centralized manner to reduce the incidence of disease, and spread quicklime once to sterilize and disinfect the soil. Alternatively, spray 50% compound carbendazim at 500 times dilution once to prevent disease, and the preventive effect is relatively good. Improve the permeability of the field or garden, and in open-field cultivation pay attention to digging ditches after rain to drain accumulated water, reduce field humidity, and do not apply too much nitrogen fertilizer. During the growing period, set up shade nets to reduce exposure to high temperature and strong light. Promptly kill spiders, longhorn beetles, spider mites, scale insects, etc., to reduce transmission vectors.
When diseased plants are found, spray chemicals promptly to control the disease. In the early stage of the disease, alternately spray 75% chlorothalonil + 70% thiophanate-methyl wettable powder (1:1) at 600-800 times dilution, or 50% compound thiophanate at 800 times dilution, or 50% kasugamycin wettable powder at 600-800 times dilution, with good control effects. The above chemicals should be used alternately, once every 7 days, for 3-4 consecutive sprays. Generally, spray promptly before or after heavy rain to control the production and spread of pathogen spores and conidia and infection, with relatively good control effects.
Common disease of lotus bamboo: leaf spot disease
Symptoms of leaf spot disease in lotus bamboo
Leaf spot disease is a fungal disease. The pathogen survives on diseased plant residues and spreads through air currents, insects, etc., and can directly infect and harm through leaf stomata. Under greenhouse conditions, it tends to occur year-round. Under humid conditions, the disease is severe.
Leaf spot disease in lotus bamboo mainly occurs on the leaves. In the early stage, the lesions are brown spots with yellow edges. After expansion, the lesions are nearly circular, gray inside, with dark brown edges and yellow surroundings. Under humid conditions, black granular substances appear on the lesions.
Prevention and control methods for leaf spot disease in lotus bamboo
During the maintenance period, control the density at which plants are placed, and maintain ventilation and light transmission. In the early stage of the disease, spray fungicides such as Ribangkangjun and phosethyl-Al manganese zinc.
Common disease of lotus bamboo: stem rot
Symptoms of stem rot in lotus bamboo
The occurrence of stem rot reduces ornamental value and, in severe cases, can even cause plant death. It occurs more often during high temperature and high humidity from May to September, and mainly harms leaves and stems.
The symptoms are: the leaves at the base of the stem of seedlings turn yellow; the stem base rots, turns yellow and softens; the interior of the stem turns red; the pathogen gradually harms upward from the lower cut.
Prevention and control methods for stem rot in lotus bamboo
Cultivate robust and well-filled plant seedlings; remove diseased plants and burn them in a centralized manner. Soak the lower cut of the seedlings for 24 hours in 42% kejunjing powder at 3000 times dilution, or 88% oxytetracycline at 1000 times dilution.
Common pest and disease prevention and control methods for anemone
News from China Landscape Network on October 27: The most common diseases of anemone include rot caused by Pythium, damping-off caused by Rhizoctonia, gray mold caused by Botrytis cinerea, and powdery mildew caused by powdery mildew fungi.
Rot disease is a disease that can be caused by several species of Pythium. It can occur regardless of whether temperatures are high or low. Under moist conditions, rot is more likely to occur and spread. It can cause germinating seeds to rot or cause disease in the roots of plants, making plant growth slow or even causing death. After infection by Pythium, water-soaked rot appears on the roots and stems of affected plants.
For the prevention and control of rot, the first step is to disinfect the soil. Quintozene or soil fungicide-insecticide can be used to dress seeds and mix with soil for sterilization and disinfection. If the disease has already occurred, Tuzet can be used for spraying and sterilization.
Rhizoctonia can cause damping-off. This pathogen prefers warm and humid environments. Compared with rot, its symptoms are brown and the depression is more obvious. Sometimes tea-colored circular patch-like mycelial masses can be found at the junction of diseased plants and the substrate. For damping-off, Medallion and Chipco 26019, etc., can be used for elimination.
Gray mold is a disease that can infect both small seedlings and occur during the flowering period. Higher air humidity and a water film on the plant surface can promote infection of plants by Botrytis cinerea.
For this disease, Mancozeb can be used for spraying, or chlorothalonil and carbendazim can be used for spraying and elimination.
Powdery mildew is a condition caused by infection with powdery mildew fungi. Its damage symptoms include spiral curling of leaves, round white spots on leaves, stems and flower buds, and affected flower buds cannot bloom, curl, and stop growing. If this disease is found, immediately spray triadimefon at 800 times dilution for elimination. If the condition is severe, spray again after 7-8 days. Three consecutive sprays can basically bring it under control.