Honeysuckle, also known as Lonicera japonica, is a perennial semi-evergreen twining shrub with strong adaptability, tolerance to moisture, drought, and cold, and can be planted in front of and behind houses, as well as on hillsides. Honeysuckle is one of China's major exported medicinal materials, and domestic demand is increasing year by year. The following are the main methods for controlling honeysuckle diseases and pests for your reference.
I. Principles of Honeysuckle Disease and Pest Control
Following the plant protection policy of "prevention first, comprehensive control," agricultural control is the foundation, combining agronomic measures with chemical control. Highly effective, low-toxicity, and low-residue pesticides should be used scientifically, and various control measures should be comprehensively applied to reduce losses caused by diseases and pests.
1. The use of highly toxic, extremely toxic, and persistent pesticides, or those with three-way toxicity (carcinogenic, teratogenic, and mutagenic), is strictly prohibited.
2. If necessary for production, production bases are allowed to use a limited amount of organic synthetic chemical pesticides, and these must be used strictly according to the prescribed methods.
3. Low-toxicity, high-efficiency, and low-residue biological pesticides and a few moderately toxic pesticides should be selected, and green and environmentally friendly machinery should be vigorously promoted.
4. The final residue of organic synthetic pesticides in agricultural products should be strictly controlled and should not exceed the national standards.
5. The interval between the last application and harvest should not be less than the prescribed number of days.
6. Each organic synthetic pesticide is only allowed to be used once during the growing season of a crop.
7. When using various biological pesticides mixed with organic synthetic chemical pesticides, only the specified varieties of chemical pesticides are allowed to be used in the mixture.
8. The use of various genetically engineered microbial preparations should be strictly controlled.
II. Common Diseases and Pests of Honeysuckle and Control Methods Common
diseases of honeysuckle include brown spot, powdery mildew, anthracnose, and rust. Pests mainly include aphids, spider mites, longhorn beetles, and inchworms.
1. Honeysuckle Brown Spot
1.1 Symptoms: This disease mainly affects the leaves. In the early stage of the disease, small yellow-brown spots appear on the leaves. In the later stage, several small spots merge together, forming round or polygonal lesions limited by the leaf veins. When moist, a grayish, frosty substance appears on the underside of the leaves; when dry, the center of the lesions easily cracks. In severe cases, leaves prematurely turn yellow and fall off.
1.2 Disease Characteristics: This disease is caused by a fungus. The pathogen overwinters on diseased leaves and produces conidia in early summer of the following year. Conidia are spread by wind and rain, generally starting from the lower leaves and gradually progressing upwards. The pathogen multiplies rapidly in high-temperature environments. The disease is generally most severe from June to August, and severely affected plants experience significant leaf drop in early autumn. According to a survey by the plant protection station, on April 29th, the average incidence of brown spot disease was 1.0%, with a maximum of 5.0%; on May 18th, the average was 7.7%, with a maximum of 40.0%; and on May 30th, the average was 30.0%, with a maximum of 60.0%.
1.3 Control Methods:
(1) Agricultural Measures: Combine autumn and winter pruning to remove diseased branches and buds, and sweep up fallen leaves from the ground for burning or deep burial to reduce the source of pathogens. At the initial stage of the disease, pay attention to removing diseased leaves to prevent its spread. Strengthen cultivation management to improve the plant's disease resistance. Increase the application of organic fertilizer, control the application of nitrogen fertilizer, and apply more phosphorus and potassium fertilizer to promote vigorous tree growth and enhance disease resistance. During the rainy season, ensure timely drainage to reduce soil moisture. Proper pruning improves ventilation and light penetration to help control disease occurrence.
⑵ Chemical control: In the early stages of disease, spray with 70% thiophanate-methyl wettable powder at 800 times dilution, or 70% mancozeb wettable powder at 800 times dilution, or iprodione at 1500-2000 times dilution. Spray once every 7-10 days, for 2-3 consecutive sprays. Alternate application of different pesticides for better control.
2. Honeysuckle powdery mildew
2.1 Symptoms: Primarily affects leaves, sometimes also stems and flowers. The initial lesions on the leaves are small white dots, which later expand into white powdery spots. In later stages, the entire leaf is covered with a white powdery layer, and in severe cases, the leaf turns yellow, deforms, and may even fall off. The spots on the upper part of the stem are brown, irregular in shape, and covered with white powder. Flowers are twisted and fall off in severe cases.
2.2 Disease characteristics: The pathogen overwinters as ascocarps on diseased plant debris. The following year, the ascocarps release ascospores for primary infection. After infection, conidia are produced on the diseased parts for secondary infection. Warm, dry conditions or shady conditions between plants promote disease development. Excessive application of nitrogen fertilizer and alternating wet and dry periods exacerbate the disease. According to a survey by the plant protection station, the disease first appeared in Zhongling on April 28. By May 18, the average incidence of powdery mildew was 8.9%, with a maximum of 40.0%. By May 30, the average incidence was 17.0%, with a maximum of 20%.
2.3 Control methods: Select and breed disease-resistant varieties (varieties with thick branches, dense and short internodes, dark green and thick leaves with dense hairs are mostly disease-resistant); reasonable planting density, pruning, and improving ventilation and light conditions can enhance disease resistance; apply less nitrogen fertilizer and more phosphorus and potassium fertilizer; at the early stage of disease, use 15% triadimefon (1500 times dilution) or 50% metalaxyl-mancozeb (1000 times dilution).