(1), the demand for nitrogen and phosphorus in the early growth stage of pomelo trees, that is, the green leaf stage and the early flowering stage, will gradually decrease until the leaves of pomelo fruits fall off after picking, and the demand for potassium fertilizer in the fruit growth stage will only last for a short time from fruit expansion to sweetness.
(2) Trace elements: In addition to a large number of elements, grapefruit also contains trace elements necessary for human body, such as calcium, manganese, zinc, copper, boron and iron. The specific time of fertilization is that the demand for calcium is increasing before June and July every year, that is, the demand for leaves is decreasing after August, while the demand for iron and boron is increasing in the early stage of fruiting, and the demand for manganese begins to increase in July.
The best time to use foliar fertilizer
1. Dehua new land foliar fertilizer can be sprayed before flowering to promote the growth of green leaves and fully supplement nutrients for flowering and fruit setting. However, it should be noted that it is not suitable to spray at flowering stage. Spraying at full flowering stage will affect pollination to a certain extent and easily cause flowers and fruits to fall off.
2. Spray after fruit setting. After 70-80% of flowers wither, we must supplement the key nutrients needed for fruit development, improve the fruit setting rate, promote the development of young fruits, and set fruits evenly.
3. Spraying foliar fertilizer during the fruit expansion period, that is, spraying foliar fertilizer during the fruit expansion and coloring period in the late fruit bearing period, can promote the fruit expansion and improve the coloring rate.
I wish you a bumper harvest of grapefruit.