Physiological leaf roll disease of potato

[Disease diagnosis] Physiological leaf curl has some similarities with viral leaf curl symptoms. It is mainly characterized by upward rolling of leaf leaflets. Usually the lower part of the plant or the whole plant leaves become brittle and roll up into a tube. Some only leaf edge slightly upward roll, some serious curl into spoon-shaped or cylindrical, serious, leaf thickening, brittle hardening, darker color, giving people a sense of cluster disorder. Physiological leaf rolling is characterized by consistent leaf rolling of injured plants.

There are several causes of physiological leaf roll: excessive nitrogen fertilizer, soil drought, water shortage, high temperature, or poor root development, damage and other factors often cause the physiological function of the plant to weaken, metabolic function is affected, so that the output of carbohydrates from the leaves is weakened, excessive accumulation of starch grains in the leaves, so that it ages, thickens, and rolls up. When the root water supply is insufficient, if the high temperature is encountered, the transpiration of leaf water is often greater than the absorption amount. If the supply exceeds the demand, the plant instinctively protects itself and adjusts the mechanism to make the lower leaves curl and reduce the transpiration area.

[Control measures](1) Strengthen management, cultivate strong seedlings, promote root development and improve root absorption capacity. (2) Avoid excessive drought in soil, irrigate water in due time, and ensure the water requirements of plant physiological functions. (3) Apply enough organic fertilizer instead of partial nitrogen fertilizer. (4) After physiological leaf rolling occurs, timely and targeted adjustment of soil conditions to promote normal growth of plants, such as cooling, irrigation, spraying micro-fertilizer, etc., can alleviate.