Illustrate the main soil-borne diseases of wheat!

In recent years, the soil-borne diseases of wheat have been increasing, which has become an important limiting factor for high-yield, high-quality and high-efficiency wheat. Therefore, research on strengthening the occurrence of soil-borne diseases and comprehensive prevention and control techniques has become an urgent problem to be solved in wheat production.

1. What are the soil-borne diseases of wheat?

Soil-borne diseases generally endanger the roots and stems of plants. Once the disease occurs in the early stage of crop growth, the roots of the seedlings rot or the stems rot and fall, the seedlings will soon die, seriously affecting crop production. The pathogen of the soil-borne disease lives in the soil, and when the conditions are appropriate, it invades the crop from the root or stem of the crop and causes disease.

Common soil-borne diseases in wheat fields include sheath blight, root rot and total erosion.

1. Sheath blight

The pathogen of sheath blight is Rhizoctonia cerealis, and sclerotia is the most important source of primary infection.

Identification:

1) Rotten bud: The bud sheath of the wheat is browned, causing the crop to die during the bud stage.

2) Diseased seedlings: In the 3-4 leaf stage, the central gray-white, brownish-colored lesions appeared on the first leaf sheath.

3) Stalks of flower stalks: After the rejuvenation and jointing, the lower part of the wheat sheath has a grayish-skinned, white-brown, striate lesion on the edge. A plurality of lesions are connected to each other to form a cloud-like flower stalk. When the conditions are suitable, "eye spots" appear on the stalk. When the humidity is high, the white mycelium of the spider silk and the yellow-brown sclerotoid like rapeseed can be seen on the inner side of the diseased sheath and on the stem.

harm:

Rotten buds, dead seedlings, stalks of flower stalks, lodging, dead ears and dead white ears. Generally, it will reduce production by 10%-20%, and severely reduce production by 50%. Some fields may even be rejected.

2, root rot

Root rot is a soil-borne disease caused by a variety of pathogenic fungi. Rhizoctonia solani, Fusarium graminearum, Fusarium oxysporum, and Fusarium oxysporum are all subfamily fungi.

Identification:

It can occur in the whole growth period, causing root rot in the seedling stage, causing leaf spots, ear rot or black embryos in the adult stage. After the disease, the seedlings produce yellow-brown to brown fusiform lesions on the bud sheath, which is far clearer and slightly faded in the middle. After expansion, it causes browning of the base, roots, tillers and stem base. The disease is necrotic and the upper part is black. Mildew, the last root is decay. The wheat seedlings are laid flat on the ground, and the lower leaves turn yellow and gradually die. Brown spots and white ears appear in the onset of spikelets.

harm:

Once infected with root rot, the stalk of wheat is easy to fold, the light yield is reduced by 10%-20%, and the heavy one can reach 70%-80%.

3, total erosion

The total eclipse is caused by the variant of the ascomycete subphylum.

Identification:

We should pay attention to the following points in the identification of total eclipse:

1) Diseased seedlings: Seed roots, secondary roots and underground stems become black and rot, and the surface of the roots is grape hyphae.

2) Before and after tillering: the old leaves turn yellow, the medicine is reduced, the growth is weak, and the dead is severe.

3) Early spring: slow greening, yellow leaves and ineffective tillers increase or die.

4) After jointing: Part of the 1-2 knots of the roots and stem bases are aggravated and the plants are dwarfed.

5) Heading and filling stage: The base of the stem is blackened and rotted more obviously, forming a "black foot". The leaf sheath of the diseased part is easily peeled off, and the surface of the inner side of the leaf sheath and the surface of the stem base form a gray-black mycelium layer. Early dryness forms "white spikes", ears are not real or kernels are thin.

harm:

The damage caused by total eclipse is also terrible. It belongs to the devastating disease of wheat, causing plants to cluster or die. It will generally result in a 10%-20% reduction in production, a serious 50% or more, or even a failure.

Second, the characteristics of wheat soil-borne diseases

1. The amount of bacteria is large. The pathogens of these diseases are transmitted through soil, seeds or diseased bodies. After years of accumulation, the amount of bacteria in the field is extremely large, and the conditions are appropriate, which may cause disease at any time.

2, strong pathogenicity. The pathogenic bacteria of these diseases are very virulence, and have great influence on roots, stems, leaves and species. Once they are infected, the shape of wheat is destroyed, the quality and yield of products are greatly reduced, and even economic value is lost.

3, early onset early. These diseases occur in the seedling stage, in the early spring, and in the late stage. The infection will start after sowing, and the first infection peak will be reached after wintering, and the second infection peak will be formed in the rainy year in spring. The disease spots will expand to cause yellow and weak seedlings; in May and May, the disease will increase and the dead seedlings will appear. Yellow leaves, white spikes, and sheets fell, causing large-scale outbreaks and a significant reduction in production.

4, the disease part is hidden. The site of the disease is mainly concentrated in the base of the root and the stem, which is relatively concealed. The disease at the seedling stage is mild and the symptoms are not obvious. In particular, the prosperous period has caused a large group, the field is sullen, and the diseased plants are not easily detected. When symptoms such as dead seedlings appear in the later stage, the control period has been missed.

Third, the cause of wheat soil disease

1. Partial application of nitrogen fertilizer: Unbalanced fertilization, especially partial application of nitrogen fertilizer, is conducive to the occurrence of wheat sheath blight and root rot. Early sowing and large amount of broadcast are conducive to the occurrence of sheath blight, total erosion and nematode disease.

2, continuous cropping: Continuous cropping of wheat and rotation with grass crops, the pathogens causing soil-borne diseases accumulate in the soil, making the wheat roots in a susceptible environment and increasing the chance of disease.

3, straw returning to the field: straw returning to the soil increased soil organic matter content, but a large number of untreated wheat diseased bodies directly mixed into the soil, resulting in a rapid increase in the number of pathogens in the soil, more even distribution, is very conducive to total erosion, The spread of pathogens such as diseases, root rots and smuts causes the spread of diseases from point to piece, from sporadic to widespread recurrence.

4. The current seed coating agent has poor quality and low control effect: According to the spot check of the Ministry of Agriculture in the past two years, the qualified rate of domestic seed coating agent is about 70%, and the qualified rate of samples taken from the market is less than 30%. The active ingredient content is even zero.

5. Farmers' awareness of disease prevention is weak: only pay attention to the prevention and control of wheat underground pests, and have insufficient understanding of the prevention and control of wheat seed transmission and soil-borne diseases. Only seed dressing with insecticides or seed dressing with inferior seed coating agents leads to wheat seed transmission. And the occurrence of soil-borne diseases is getting heavier and heavier.

Fourth, the comprehensive prevention and control of wheat soil-borne diseases

Wheat soil-borne diseases are based on agricultural control, with chemical control as the leading factor, and coordinated use of various measures to effectively control the occurrence of such diseases.

1. Strengthen plant quarantine.

Breeding of wheat seeds must be reported to the quarantine department 15 days before sowing. Breeding materials must be quarantined and quarantined; it is strictly forbidden to breed wheat seeds in areas where quarantine objects such as total ecstasy and smut are quarantined; It shall not be promoted and used in production. Units and individuals who arbitrarily breed, transport and operate wheat seeds in violation of the phytosanitary regulations shall be seriously dealt with according to law to ensure the control of the spread of quarantine diseases of wheat from the source.

2. Agricultural control.

1 Choose resistant varieties. In the area of ​​total rot disease and sheath blight, wheat varieties such as Yumai 18, Yumai 49, Xinmai 11, Zhoumai 18, Gaoyou 505 and Dwarf 4110 should be planted.

2 rounds. In the wheat-removing disease recurrence area, non-grass crops were replanted to reduce the number of pathogenic bacteria in the soil and give full play to the antagonism of beneficial microorganisms in the soil.

3 fine land preparation. Implement deep ploughing, intensive cultivation, improve the quality of sowing, and promote the early growth of wheat seedlings.

4 reasonable fertilization. Add organic fertilizer, apply wheat special formula fertilizer, avoid partial application of nitrogen fertilizer and organic fertilizer with diseased body.

5 strengthen management. Avoid early sowing, reasonable close planting, timely tillage in the greening period, promote the development of wheat roots, and create an ecological environment conducive to wheat growth and not conducive to disease occurrence.

6 eliminate the sick body. After the wheat is harvested, the sick body will be cleaned up in time, and the diseased residue of root blight and root rot should be brought out of the field for centralized treatment. Sick smut and total ill disease are burned on the spot and expanded with immunity.

3. Chemical control.

It is necessary to grasp two key measures: one is to treat the seeds with chemicals, and the seeds are treated in a targeted manner when planting; the other is to prevent the early spring wheat from returning to the field and injecting the drug into the root or stem base of the plant.

1) Chemical dressing. 3% difenoconazole 50-100 ml to water 100-150 ml, mix well, then mix 10 kg of wheat (acre). It can be sown after 3 hours of boring. This method not only has a good control effect on wheat total etch, but also has a protective effect on wheat smut, root rot, sheath blight and early rust and powdery mildew. When seed dressing, insecticides such as methyl isothiophosphate or phoxim may be added to control underground pests such as cockroaches, golden worms and cockroaches.

2) Medicinal root irrigation. During the greening period of wheat, in the area of ​​total eclipse and sheath blight, 20 ml of triadimefon 100 ml per acre and 50 kg of water can be used to control a variety of soil-borne diseases, and treat powdery mildew and rust. In the early stage of wheat root rot, 15% triadimefon emulsifiable concentrate 40-60ml/mu + 50% carbendazim WP 50-60g/mu, or 25% tebuconazole emulsifiable concentrate 25-40ml/mu. Spray 75kg with water.

Drop-in bathtub is designed for hotel and personal bathroom. We have single and double ended styles. Many different shapes and styles are available. Drop-in Tubs bring serenity and relaxation by being amazingly comfortable, and durable enough to withstand everyday use. This classic style will sit flawlessly in any decor scheme, bringing you amazing style to match your contemporary style bathroom.

Drop-in Tubs

Drop In Bathtub,Bath Company,Drop In Soaking Tub,Tubs For Sale

Ningbo Waltmal Sanitary Wares Co., Ltd. ,