What are the symptoms of rice akagare disease?

Rice akagare disease is also known as rusty disease, and it is a common physiological disease in rice cultivation. The occurrence of this disease can easily cause yield reduction in rice. What are the symptoms of rice akagare disease? How should it be prevented and controlled?

1. Symptoms of rice akagare disease

1. Cold-damage type: mostly occurs in muddy fields, deep-foot fields, cold-soaked fields, and shaded fields, caused by low soil temperature or early transplanting exposed to cold waves. After transplanting, the seedlings are slow to turn green and do not develop roots; the root system ages, becomes brown and soft, with few and thin roots, hindered vigor and slow growth; the leaves are upright, with irregular brown spots near the tips, gradually spreading along the edges toward the base; the lower leaves turn yellow, and the plant is short and small.

2. Nutrient-deficiency type: caused by a lack of nutrient elements; the deficiency of elements leads to blocked physiological metabolism in the seedlings. In fields deficient in phosphorus, the seedlings have few new roots, a weak and thin root system, and brown-black roots; the seedlings appear brush-like, and the leaves are dark brown. In fields deficient in potassium, root growth is weak, the leaves are short and dark green, old leaves have reddish-brown spots, the leaves break easily, and the main leaf veins turn yellow. In fields deficient in zinc, the central leaves of the seedlings curl and are difficult to emerge, chlorotic streaks appear on the leaf surface at the seedling stage, the roots are short and few, the leaves turn white, and the leaves are arranged in a palmate pattern.

3. Toxic type: mostly occurs in deep-foot fields under long-term flooding, trough fields with poor soil permeability, muddy fields, and highly fertile fields around houses. The seedlings turn yellow and do not turn green; the roots gradually change from brown to yellow, become soft and shrink; the old leaves turn yellow and have reddish-brown spots on the leaves. In severe cases, the lower leaves of the whole plant turn red, occurring in patches or clumps, and the seedlings appear clustered and upright.

2. How to prevent and control rice akagare disease

(1) Improve the soil, deepen the plow layer, increase the application of organic fertilizer, raise soil fertility, and improve soil aggregate structure.

(2) Apply potassium fertilizer early, such as potassium chloride, potassium sulfate, plant ash, and potassium-calcium fertilizer. For phosphorus-deficient soil, apply superphosphate early and in a concentrated manner at 30 kg per mu, or spray a 0.3% potassium dihydrogen phosphate aqueous solution. Do not apply nitrogen fertilizer alone as a topdressing, otherwise the disease will worsen.

(3) Renovate low-lying waterlogged fields and make drainage ditches. When using green manure as a base fertilizer, do not apply excessively, and do not plow too late. Organic fertilizer must be fully decomposed and applied evenly.

(4) For early rice, irrigate shallowly and frequently, and weed the fields in time to increase soil permeability.

(5) For affected rice fields, drain the water immediately, apply an appropriate amount of lime, and carry out light field drying to promote the settling of floating mud and facilitate the early emergence of new roots.

(6) From the booting stage to the grain-filling stage of rice, spray the multifunctional high-efficiency liquid fertilizer Wanjiaobao at 500-600 times dilution on the leaves, once every 15 days.

(7) For the prevention and control of the cold-damage type, strong seedlings mainly raised by dry seedling cultivation can be cultivated to enhance cold resistance; muddy fields, deep-foot fields, and cold-soaked fields can adopt semi-dry cultivation to raise soil temperature; dig ditches to divert cold-soaked water; use shallow irrigation, drainage and field drying, and increase temperature and aeration to reduce toxicity.

(8) For the prevention and control of the toxic type, semi-dry cultivation can be adopted to improve soil aeration and reduce reduced toxic substances; apply more organic fertilizer, do not apply undecomposed organic fertilizer, and plow green manure in early to let it decompose and rot; drain and dry the field to increase temperature and aeration; apply lime to neutralize toxic substances, and increase the application of phosphorus, potassium, and ash fertilizers to enhance stress resistance; irrigate shallowly and frequently.

This is the end of the brief introduction to rice akagare disease. Friends who need it can take a look, and I hope it is of some help to everyone.