Key Techniques for Improving Longan Fruit Quality
Longan, also known as yuanrou or guiyuanrou, has the effects of tonifying the heart and spleen and nourishing the blood to calm the mind, and is a well-known bulk medicinal and edible delicacy. It is mainly produced in Fujian, Guangdong, Guangxi, Sichuan and Taiwan, China. Its cultivation can use two methods: seed propagation and grafting propagation. The seed seedling-raising technique is introduced as follows: 1. Selection of nursery land. The nursery...
Improving fruit quality is a comprehensive technical measure. First, cultivation and management work in the orchard must be strengthened, more fruit-swelling fertilizer must be applied, and pest and disease control during the fruiting period must be done well. For fruit trees bearing more fruit, a second application of fruit-swelling fertilizer can be made in early June. For trees with a canopy of 5-6 m, apply one dan of bran water per tree (equivalent to 1 kg of dry bran), or 1 kg of compound fertilizer with a nitrogen, phosphorus and potassium ratio of 15:15:15 plus 0.5 kg of urea. Trees bearing a lot of fruit can also be fertilized once each at the end of June and in mid-July.In terms of pest and disease control, the main work is to control the litchi stem-end borer, the litchi fruit borer, the litchi stink bug, and scarab beetles, etc.
Second, fruit thinning must be done well. Longan trees "spare the fruit but not themselves," and often bear too much fruit. Bearing too much fruit affects fruit quality, making the fruit small and the soluble solids low. Therefore, fruit thinning must be carried out at the end of May and in early June on plants bearing too much fruit. A moderate fruit load can fully bring out the original characteristics of the variety.
Third, during the fruit development period, some drugs can be used to promote fruit development and improve fruit quality, such as the "Nutrient High-Yield Formula" prepared by the Longan Office of the Fruit Tree Research Institute of the Provincial Academy of Agricultural Sciences. Spraying begins 10 days after the longan trees finish flowering, once every about 20 days, for a total of 3-4 sprays over the whole fruiting period, which can effectively raise the nutritional level of the tree, promote fruit development, and increase the sugar content and quality of the fruit. In addition, according to experiments in Yunxiao County, Fujian, starting 50 days before longan harvest (when the longan seeds are just about to turn black), spraying compound triacontanol (TA) milk powder once every 10 days for 3 consecutive times can significantly increase the yield and quality of longan. The fruit becomes larger, the flesh is thicker, the flavor is richer, and the appearance color is better.
Fourth, fruit cluster bagging should be carried out to protect the fruit. In early June, after the second physiological fruit drop of longan ends, use 35 x 30 cm plastic mesh bags to bag the fruit clusters, which can reduce fruit drop and fruit cracking, reduce damage by fruit-eating pests, and improve the appearance color of the fruit. Finally, provide sufficient water during the fruit development period, and irrigate promptly in case of drought, especially in the middle and late stages of fruit development, ensuring water supply can promote longan fruit development, enlarge the fruit, and increase yield.