What is the best fertilizer for grapefruit trees?

Pomelo , a plant of the genus Citrus in the Rutaceae family, is known for having the largest fruit diameter among citrus fruits. The pulp of pomelo is not only suitable for direct consumption, but can also be processed into a variety of products such as juice. The temperature range suitable for grapefruit growth is 23 to 29 degrees Celsius, and it prefers warm and humid climatic conditions. In our country, the cultivation history of pomelo is very long. To achieve high and stable yields of pomelo trees , fertilization is a key link. Applying fertilizer at the right time and in the right amount can help grapefruit develop better during the growth process. Let’s learn in detail what fertilizer is best for pomelo trees?

1. Fruit picking fertilizer

Different varieties of grapefruit mature at different times. Timely fertilization after harvesting is an important measure to supplement nutrition and promote production. Fertilization helps grapefruit trees recover quickly, especially the wounds caused by fruit picking. By spraying 0.5% potassium dihydrogen phosphate aqueous solution combined with foliar fertilizer and methyl thiophanate, the tree's resistance can be enhanced to ensure productivity in the coming year.

2. Winter fertilizer

For varieties that are picked later, in order to maintain high and stable yields, winter fertilizer should be applied immediately after the fruits are picked. The application of winter fertilizer should be advanced to autumn as much as possible. By digging trenches around the roots and mixing fully decomposed farmyard manure and special fertilizer for fruit trees, the high temperature of the soil can be used to promote the root system to absorb nutrients and provide sufficient nutrition for flower bud differentiation.

3. Spring fertilizer

Chemical fertilizers are mainly used for fertilizers in early spring. For grapefruit trees that have entered the fruiting period, management measures such as ring cutting are used to promote reproductive growth. After ring cutting, spray urea aqueous solution and foliar fertilizer to promote wound healing. According to the size of the tree, apply appropriate amounts of urea and high-nitrogen ternary compound fertilizer , and note that the fertilization should be away from the tree trunk.

4. Fertilizer during flowering period

The flowering period is the peak period of nutrient consumption, and timely nutrient supplementation can effectively increase the fruit set rate. Six days before flowering, spray amino acids, boron fertilizer, phosphorus fertilizer and foliar fertilizer on the leaves. At the end of flowering, after about 70% to 80% of the flowers have withered, spray again and add brassinolide and gibberellin. From the appearance of buds to the end of flowering, foliar fertilizer needs to be sprayed several times, and high-potassium foliar fertilizer also needs to be sprayed after flowering.

5. Fruit-stabilizing fertilizer

Also known as physiological fruit drop fertilizer, grapefruit has two physiological fruit drop periods, after flowering and before the fruit expansion period. Two weeks before the fruit drop period, spray 1% superphosphate extract and brassinolide, and apply urea or decomposed human manure to the roots to reduce fruit shedding.

6. Enlarging fat

After the second physiological fruit drop period, the fruit enters a rapid expansion stage. At this time, the proportion of nitrogen fertilizer should be reduced, potassium fertilizer and calcium fertilizer should be increased, and magnesium should be supplemented to promote good fruit growth and improve the quality of grapefruit. It is better to use fully decomposed livestock and poultry manure as fertilizer.

The above are the key points of fertilization at different growth stages of pomelo trees, which can ensure that the pomelo trees obtain appropriate nutrients at each growth stage, thereby achieving the goal of high and stable yields.