Introduction and control of powdery mildew of clover

In fact, clover is quite common in our life, it has high ornamental value, and it is generally used in lawn construction in greening construction in our country. Clover has a strong life and low requirements for soil, so it is one of the more viable plants.

What is clover?

Clover, also known as clover, is a perennial herb. There are two main types, namely white clover and safflower clover. Clover is a high-quality leguminous forage with soft stems and leaves, rich leaves, high crude protein content and low crude fiber content. it can not only feed livestock, but also feed herbivorous fish. Among them, white clover (Triofliumrepens), because of its low plant and strong adaptability, can be used as an excellent plant for urban greening and lawn construction.

Growth habits of clover

Stop growing but still stay green. Therefore, the green period is very long. The requirement of soil is not strict, it can adapt to various soil types, and grow well in acidic soil. Like warm, sunny, good drainage environmental conditions. The growth is slow under the condition of drought, and some die in the high temperature season. Resistant to pruning, trampling, strong regeneration ability, regeneration leaflets can grow within 10 days after pruning. After high strength trampling or rolling, it can be recovered in 3 ~ 5 days. It is easy to grow under strong shade, resulting in poor growth. Strong ability to resist harmful gas pollution and disease and insect pests.

Clover has strong cold tolerance. When the temperature dropped to 0 ℃, some of the old leaves were withered and yellow, and the leaflets on the main root were close to the ground and stopped growing, but still remained green. New leaflets can grow within 10 days after pruning. After high strength trampling or crushing, it can be recovered in 3 ~ 5 days. Strong ability to resist harmful gas pollution and disease and insect pests. Red flowers bloom during the day, petals are five-petal, and flowers are folded into a bunch at night; by comparison, it is found that stems and leaves begin to wither and wither after opening at the turn of spring and summer. It is common in planting in our country, and it is semi-authigenic in wet grassland, river bank and roadside.

Introduction and control of powdery mildew of clover

Powdery mildew is a common disease on clover, which occurs widely in various planting areas of the country, which seriously affects the yield and quality of hay. 1. Symptoms of clover powdery mildew:

In the early stage, the two sides of the leaf reappeared the white powder spot composed of the mycelium and conidia of the pathogen, and then quickly covered most or all of the leaf. When the disease is prevalent, the whole grass seems to have been sprayed with white powder. In serious cases, it can make the leaves yellow or withered, and the seeds are unfruitful or shrunken. In the later stage, there are many small black-brown spots on the white plaque, that is, the closed capsule of the pathogen. 2. the pathogen of clover powdery mildew:

ErysiphepisiDC. It is called powdery mildew of pea, belonging to ascomycete subphylum fungi, synonymous polygonum powdery mildew (E.polygoinDC.). Conidiophores grow from exophytic hyphae, erect, colorless, terminal conidia; conidia barrel-shaped, or obtusely round at both ends, unicellular, colorless, about (22.9) 25.4-38.1 (43.2) μ m × (11.4) 12.7-17.8 (18.3) μ m; closed capsule oblate, dark brown, about (72) 92 μ m-120 (130) μ m in diameter, individual up to 150 μ m Accessory hyphae, hyphal, about (0.5) 1-3 (5) times as long as the diameter of the closed theca, brown at the base, fading to colorless toward the top; many ascyst, ovate, elliptic, a few subglobose, shortly stipitate to subsessile, (43.2) 55.9-76.2 (86.4) μ m × (30.5) 35.6-43.2 (48.3) μ m; endophytic (2) 3-5 (6) ascospores Ascospores unicellular, yellowish, ovate or oval, (17.8) 20.3-25.4 (27.9) μ m × (11.4) 12.7-15.2 (16.4) μ m. It has a wide range of parasites in legumes, but it adapts to different hosts and differentiates into many physiological races. As far as the three genera are concerned, the occurrence of red clover is more common, and occasionally seen in white clover, crimson clover, miscellaneous clover and so on.

Third, the incidence characteristics of clover powdery mildew:

The pathogen overwintered mainly as dormant hyphae in the host. In most clover planting areas, conidial stage (Oidiumsp.) is the main pathogen. For example, in Guizhou, China, red clover does not produce sexual closed cysts, and wild white clover in Xinjiang rarely forms closed cysts. The conidia are spread by the wind and can be re-infected many times in the growing season, resulting in the epidemic of the disease. The favorable conditions of dampness and heat during the day and cool and windy at night are conducive to the prevalence of the disease. Rainy or too humid is not conducive to the occurrence of diseases. Excessive application of nitrogen or phosphorus fertilizer aggravates the occurrence of diseases. The application of potassium fertilizer can inhibit the growth of mycelium and alleviate the disease.

Control methods of powdery mildew of clover

1. Breeding and planting disease-resistant varieties according to local conditions.

2. Strengthen the field management. Sowing at the right time, reasonable close planting; scientific fertilization, increase the application of phosphorus and potassium fertilizer, improve plant disease resistance; timely irrigation, pay attention to drainage after rain; rational use of grassland, timely cutting, moderate grazing, control the spread of diseases.

3. Chemical control. Carbendazim, methyl thiophanate and trimethoprim can be used to control the disease in scientific research or seed breeding areas. The control effect can be significantly improved when the above agents are mixed with disease-preventing and high-fat film agents. Commonly used agents carbendazim, methyl thiophanate, trimethoprim

Although it is said that clover is better to survive, the requirements for the living environment and soil are not very high, and its vitality is relatively tenacious, but it sometimes gets sick. Timely prevention of clover disease is the most critical factor in planting clover. Don't think it's easy to feed, but don't take it lightly.