Severe crop losses caused by cold wave symptoms of frost injury of sugarcane and its prevention and treatment

Sugarcane frost injury

1. Symptoms of sugarcane frost injury:

1. Growth point and heart leaf: when sugarcane is frozen, the heart leaf dies first, and then the growth point dies. After death, the heart leaves are black and easy to pull up. If the growing point dies, no new leaves can be drawn after frost. If the growing point is not dead, after the heart leaf is frozen, the new leaf unfolds with butterfly white spots, and the heart leaf can continue to produce.

2. Leaves: the damaged leaves can not carry out photosynthesis, and the dry leaves are gray.

3. Sugarcane buds: the degree of freezing injury of sugarcane buds is related to the old and tender buds and the coating of leaf sheaths. The cold tolerance of the upper buds of sugarcane is weak, and there are more dead buds after freezing injury, while the lower buds are older, with leaf sheath, strong freezing resistance, light brown and less dead buds after freezing injury. However, when the frost is serious, it often kills all the sugarcane buds above ground and even underground.

4. Sugarcane: the freezing injury of sugarcane is serious, some or all of its tissue is cooked, there are reddish-brown spots at internodes, sometimes internodes crack, sucrose is gradually hydrolyzed and smells of acid rot.

2. Measures for prevention and rejuvenation of freezing injury of sugarcane:

1. Smoke to ward off cold. Smoke materials such as straw, weeds, sugarcane leaves, grain husks, withered branches and sawdust can be used to set up several fires in the upwind direction of the sugarcane field before frost or strong cold weather and from night to dawn the next day. According to the size of the area, a number of fires can be set up to smoke, only thick smoke can be put out, so that the smoke can be diffused in the lower space off the ground to raise the air temperature and achieve the purpose of preventing frost and frost damage. This method is best in clear skies, no clouds and no wind, use before frost, strong cold and wet weather is also good.

2. For sugarcane that is not frozen or lightly frozen, especially the new varieties, in order to prevent secondary freezing injury, the sugarcane seeds can be cut down with sheath and left behind in time, and the sugarcane seeds can be covered with plastic film to ensure that sugarcane can be planted the following year.

3. If there are conditions for the lightly frozen sugarcane, it should be irrigated into the field as soon as possible to increase the temperature of the sugarcane field and prevent the freezing injury from aggravating. Potassium dihydrogen phosphate or antifreeze can be sprayed.

4. The ratoon sugarcane harvested before freezing injury and the winter sugarcane planted without film should be covered with film, straw and sugarcane leaves in time to ensure safe overwintering. During the period of cold injury, the ratoon sugarcane should not be ridged and loosened, so as not to freeze the sugarcane buds.

5. According to the degree of disaster, cut and press in time. According to the principle of first heavy and then light, we should pay close attention to chopping and pressing, shorten the retention time of frozen sugarcane in the field, and reduce the loss of sugar and yield.