Time and method of fertilization for pomegranate trees

Fertilization time of pomegranate trees

Mid-May and mid-October. Generally speaking, quick-acting nitrogen fertilizer, combined with phosphate fertilizer, should be applied in the first and middle of May before flowering to promote vegetative growth. The application of n, p, k compound fertilizer in the post-anthesis fruiting stage and young fruit expansion stage promoted the rapid growth of young fruit and the formation of flower bud at the same time. At the same time, extra-root topdressing should be carried out many times during the growing season, and the leaves should be sprayed with 0.3%-0.5% urea or 1% diammonium phosphate. When trace element deficiency is shown, micro-fertilizer should be sprayed in time.

In the middle of September, a large number of fruits are ripe and harvested one after another. Autumn pruning was carefully carried out after harvest, and base fertilizer was applied in time, mainly farm organic fertilizer. The application of base fertilizer in autumn should be finished before the middle of October, and fertilization in winter should be avoided.

Fertilization method of pomegranate tree

It can be divided into two forms: soil fertilization and extra-root (foliar) topdressing, which is mainly soil fertilization and supplemented by extra-root topdressing.

(1) soil fertilization is to apply fertilizer to the rhizosphere of fruit trees to facilitate absorption. The effect of fertilization is closely related to the method of fertilization. It should be determined according to topography, topography, soil texture, fertilizer types, especially root distribution. The horizontal root groups of pomegranate trees are generally concentrated in the periphery of crown projection, so the depth and breadth of fertilization should change from inside to outside, from shallow to deep with the increase of tree age.

(2) extra-root (foliar) topdressing means that a certain concentration of fertilizer solution is evenly sprayed on the leaves of pomegranate trees. First, it can increase tree nutrition, increase yield and improve fruit quality, generally increase fruit setting rate by 2.5%, fruit weight by 1.5%, fruit weight by 1.5%, and yield by 5% and 10%. Second, it can supplement the demand for trace elements of some deficiency diseases in time. Foliar fertilization has the advantages of fast absorption, fast reaction and obvious effect, which can be absorbed from 15 minutes to 2 hours after spraying, and the leaves respond obviously to fertilizer elements in 10-15 days, which can avoid the disadvantages of many trace elements being easily fixed by soil and reducing fertilizer efficiency.

25-30 days after foliar fertilization spraying, the response of leaves to fertilizer elements gradually disappeared, so it can only be the supplement of soil fertilization, and a large number of nutrients needed for pomegranate tree growth and fruit should be satisfied by soil fertilization.

During foliar fertilization, the nutrients of fertilizer mainly enter the leaf through the stomata and stratum corneum, and then run to all organs of the tree. The dorsal part of the leaf has more stomata and larger intercellular space than the leaf surface, which is beneficial to penetration and absorption. The optimum temperature of foliar fertilization is 18 °C-25 °C, so the best spraying time in summer is around 10:00 in the morning and after 4 p.m. Spray atomization is better, spray evenly, pay special attention to increase the amount of fertilizer on the back of the leaf.

Generally, water-soluble fertilizers can be used for extra-root topdressing, and different fertilizers are selected according to the purpose of fertilization. Foliar fertilizer can be combined with pesticides to control diseases and insect pests. However, when mixed spraying, attention must be paid not to reduce the efficacy and fertilizer effect. For example, alkaline pesticide stone-sulfur mixture and Bordeaux solution can not be mixed with calcium superphosphate, manganese, iron, zinc and molybdenum, while urea can be mixed with Bordeaux solution, dichlorvos, phoxim, arsine, zinc, thiram and other pesticides. The concentration of foliar spraying should be accurate to prevent drug and fertilizer damage. When spraying, a small amount of wetting agents can also be added, such as soap liquid, washing powder, soap horn oil, etc., which can make fertilizers and pesticides adhere to the leaf surface and improve the effect of fertilizer absorption and pest control.