According to the fertilization law of bitter gourd and the key points of safe and efficient production, the fertilization of bitter gourd should adopt the scientific fertilization method with base fertilizer as the main fertilizer and topdressing as the supplement. In the case of sufficient organic fertilizer, add appropriate amount of chemical fertilizer. Chemical fertilizer can be ternary compound fertilizer, nitrogen fertilizer is mainly urea, phosphate fertilizer can be superphosphate or diammonium phosphate instead, and potash fertilizer can be potassium sulfate. The amount of fertilization can be determined according to the soil fertilization and the target yield, and 70% of the total fertilization amount is used as base fertilizer and 30% as topdressing.

Base fertilizer:

The base fertilizer of bitter gourd refers to the fertilizer applied before the bitter gourd is sowed or planted. It can not only supply the nutrients needed by the balsam pear plant throughout its growth period, and create good nutritional conditions for the growth and development of balsam pear, but also has the effect of improving soil and fertility. Most fertilizers used as base fertilizers are late-acting fertilizers. For example, organic fertilizer, compost, livestock manure, etc. are the most commonly used base fertilizers. The full-effect slow (controlled) release fertilizer or phosphate fertilizer and potash fertilizer of chemical fertilizers are generally used as base fertilizer.

Top dressing:

(1) Soil top-dressing and top-dressing should be carried out in accordance with the principles of light in the early stage, heavy in the middle, and supplement in the later stage. Generally, the first top-dressing is carried out after flowering and fruit setting. The type and quantity of fertilizer used: ternary organic-inorganic biological fertilizer 50 kg/field, or Urea 15-20 kg + potassium sulfate 10-15 kg/mu. After each harvest of melons, 15 kg of urea is applied per mu. Apply 50 kg/mu of ternary organic-inorganic bio-fertilizer every 2 times of melon harvest. To prevent premature senescence of plants and affect fruit growth.

(2) During the growth period of bitter gourd, use a thin solution of inorganic fertilizer, trace elements or growth hormone, combined with artificial rainfall or spray a low-concentration fertilizer aqueous solution onto the plant. By the movement of water, The fertilization method in which the stomata of the branches and stomata enter the plant body is called foliar topdressing, also known as foliar topdressing and root topdressing.

The role of balsam pear foliar spraying Foliar spraying fertilizer can timely supplement the required nutrients for the plant to meet the needs of its growth and development when other fertilization methods are not allowed and in some specific circumstances. Foliar spraying has a significant effect on increasing the yield of balsam pear, especially in the fruiting period of balsam pear, when it is invaded by diseases and insects, and when there are symptoms of fertility deficiency, spraying foliar fertilizer can timely supplement the nutrients needed in the fruiting period of balsam pear. It is conducive to the good development of the young bitter gourd fruit, more fruiting melons and large melons, reducing deformed fruit, thereby increasing the yield and commodity rate of bitter melon.

Foliar topdressing should be based on a mixture of nitrogen, phosphorus, and potassium or multiple compound fertilizers. Therefore, before determining the type of foliar fertilizer, it is best to determine the content of each element in the soil and the pH of the soil, and what to make up for what is lacking in order to achieve the full effect of fertilizer. If conditions permit, the content of nutrient elements in bitter melon plants can also be determined, or the type and amount of foliar fertilizer can be determined according to the lack of nutrients.