Latest Symptom Identification and Control Measures for Wheat Take-All Disease

Wheat take-all disease is a quarantine fungal disease of wheat. It causes severe damage and spreads quickly. The pathogen generally survives in the soil for more than 7 years. Affected by factors such as environment and variety, the degree and scope of the disease increase to varying extents, and it can reduce wheat yield by 20%-35%. In severely affected fields, yield is reduced by nearly half or even total crop failure. It is a devastating disease of wheat, known as the "cancer" of wheat.

1. Disease characteristics

It generally takes only about 2-3 years for a wheat field to go from scattered occurrences to patchy death. The filling stage to the milk-ripe stage of wheat is the period when take-all symptoms are most obvious.

2. Disease symptoms

Stunted plants, dry withered plants, white heads and black feet, etc. Therefore it is also called the "three blacks" - black roots, black feet, black plaster.

3. Disease pattern

Take-all is a soil-borne fungus. Seed-borne infection and mechanical operations are the main pathways for long-distance spread. The optimum temperature for disease development is 15℃-24℃.

4. Control methods

(1) Crop rotation. The wheat take-all pathogen survives in the soil for a long time. For wheat farmers, crop rotation is difficult to carry out, and its effect is also poor.

(2) Seed treatment. Because the fungus also spreads through seeds, seed dressing is highly effective at killing the pathogen on the seed surface and in the surrounding soil after sowing. Through many years of experiments, silthiopham has shown good killing activity against the wheat take-all pathogen. Therefore, seed dressing with wheat take-all cleaner made from silthiopham is the first choice for wheat farmers. Mix 100 g of wheat take-all cleaner with 15-20 kg of seed, then dry and sow.

(3) Foliar spraying. For heavily affected fields, in addition to seed dressing, spray wheat take-all cleaner (foliar spray type) 2-3 times from the wheat regreening stage to the filling stage. The control effect can reach about 85%-90%. Add 20-25 g of wheat take-all cleaner (foliar spray type) to 15 kg of water and spray evenly. The specific spraying times are as follows:

① Spray take-all cleaner at the wheat regreening stage;

③ Spray take-all cleaner at the wheat filling stage.

4. Key points for take-all cleaner in controlling take-all disease

(1) Seed dressing alone gives a control rate of 60%-70%.

(2) Seed dressing + spraying gives a control rate of more than 85%-90%.