Preventive measures of pomegranate fruit cracking in North China

Preventive measures of pomegranate fruit cracking in North China

1. Selection of fruit varieties resistant to cracking

Popularizing the improved varieties of pomegranate with crack resistance is the fundamental way to solve the problem of pomegranate cracking. Qiuyan, a new pomegranate variety with outstanding anti-cracking performance, can be selected in production.

two。 Reasonable establishment of garden

The important reason for pomegranate fruit cracking is the rain before harvest. From August to September in the north, pomegranate fruit enters the later stage of development, and fruit cracking is very easy to occur if rain occurs after a long period of drought. In view of the uneven problem of Rain Water, consideration can be given to the establishment of a garden by means of facility cultivation and the construction of a steel frame structure greenhouse (which can be multi-span). In August-September when it is easy to meet with drought and rain, the timely buckling of the shed can reduce the occurrence of pomegranate fruit cracking. The span of the single shed is 8 to 9 meters, so that three rows of pomegranate trees can be planted. The highest arch of the shed is 3.0m to 3.5m and the lowest is about 2.5m. This structure can minimize the effect of greenhouse film on tree growth and improve the utilization rate of space in the shed [Jishan Huayao].

3. Strengthen management

(1) fertilization. Increase the application of farm manure, reduce the application of nitrogen fertilizer, and assist the application of foliar fertilizer. In autumn, each pomegranate tree applied 10kg more farm manure and less nitrogen fertilizer. During the fruit expansion period, 0.3% potassium dihydrogen phosphate solution or 0.15% calcium chloride solution was sprayed once every 7 to 10 days for 3 times in a row, which could significantly enhance the fruit toughness after pomegranate ripening.

(2) irrigation. In case of prolonged drought and no rain, irrigation should be based on the principle of "small amount, balance and multiple times". The young fruit was irrigated every 10-15 days. Close to the rainy season, gradually increase the number of irrigation in order to improve the air humidity in the garden, enhance the adaptability of the pericarp to the high humidity environment, and prevent the occurrence of fruit cracking. Stop watering when the fruit is nearly ripe. When there is stagnant water in the soil, it should be drained in time to prevent fruit cracking caused by high soil moisture content.

(3) Application of growth regulators. In the young fruit stage of pomegranate, the foliar spraying concentration of paclobutrazol solution was 300 mg / L, and in the later stage of fruit development, spraying gibberellin solution of 25 mg / L could significantly reduce the fruit cracking rate of pomegranate fruit.

(4) fruit bagging. Bagging can prevent fruit cracking, prevent diseases and insect pests, increase fruit surface finish and improve fruit commodity value. The specific operation methods are as follows: in the young fruit stage, a double-layer special fruit bag of 20 cm × 23 cm is selected. Before bagging, the whole tree was sprayed once with a mixture of 80% mancozeb 800x and 20% fenpropathrin EC 2000 times to kill diseases and insect pests on the fruit. Pick the bag about 15 days before fruit picking to promote fruit coloring.