Fertilizing Techniques for Vegetables During the Full Fruiting Stage and the Effects of Over-Fertilizing

After vegetables enter the full fruiting stage, they also enter the peak period of water and nutrient uptake. Although their nutrient requirements are roughly the same, that is, low nitrogen, low phosphorus, high potassium, or medium nitrogen, low phosphorus, high potassium, different vegetable types and different cultivation management methods differ somewhat in terms of fertilizer use. So, which fertilizing techniques should be mastered during the full fruiting stage of vegetables?What are the effects of over-fertilizing?

I. Fertilizing Techniques for Vegetables During the Full Fruiting Stage

During the full fruiting stage of vegetables, the plants have a high demand for nutrients. It is recommended that vegetable growers apply a full-nutrient water-soluble fertilizer with comprehensive nutrients and high absorption and utilization. First, it can meet the nutrients needed for the growth of roots, stems, leaves, flowers and fruits, avoiding nutrient imbalance and other deficiency phenomena; second, it has high absorption and utilization, reducing fertilizer loss and lowering the degree of soil salinization. Examples include the Netherlands' Yipurun Gencchisu, Germany's Panta water-soluble fertilizer, and so on. In addition, medium and trace elements are indispensable. For example, boron is very necessary for plant pollination, fruit setting and seed development. Supplementing boron-containing fertilizer can promote flower bud differentiation and prevent the phenomenon of flowers failing to set fruit. It is recommended that vegetable growers spray medium and trace element fertilizers on the leaves to promote rapid absorption by the plants, such as spraying Yipurun Yechisu, Gaiyimei, and so on.

1. Control the amount of nitrogen fertilizer during the full fruiting stage of tomatoes

After tomatoes enter the full fruiting stage, fruit enlargement and color change become the key to improving marketability. Many vegetable growers easily fall into the mistaken idea that fruit enlargement and color change affect each other.

Tomato fruit production is relatively concentrated. Usually the upper fruits are in the enlargement stage while the middle and lower fruits are in the color-changing stage. During this period, there needs to be sufficient nutrient supply, and at the same time nutrients must not be excessive so as not to affect color change.

It is understood that many vegetable growers who plant tomatoes face such a problem: after continuously applying fertilizer several times, the fruits show more rib rot, which affects fruit color change. The reason such a problem occurs is mostly that vegetable growers use too much fertilizer and do not choose a suitable content ratio. Generally speaking, if the fertilizer used contains more ammonium nitrogen, it will affect the absorption of potassium fertilizer, and the carbon-to-nitrogen ratio in the fruit becomes imbalanced, thereby affecting color change.

Therefore, during the full fruiting stage of tomatoes, excessive input of nitrogen fertilizer needs to be controlled. Generally speaking, during the full fruiting stage of tomatoes, a water-soluble fertilizer with low nitrogen, low phosphorus and high potassium can be chosen. Taking a product with a content of 60 as an example, use no more than 20 jin per mu each time.

2. Nitrogen and potassium use during the full fruiting stage of eggplant must be coordinated

The coordinated use of nitrogen and potassium depends on the cultivation method of eggplant. Taking long eggplant as an example, most vegetable growers adopt the cultivation method of fruiting on short branches, that is, when the two main stems grow to the height of the trellising wire, they are topped, and the secondary branches are used for short-branch fruiting. The growth of secondary branches requires a certain supply of nitrogen fertilizer, while fruit enlargement has a relatively large demand for potassium.

Therefore, during the full fruiting stage of eggplant, topdressing should mainly use a fertilizer ratio of medium nitrogen, low phosphorus and high potassium. Generally, about 25-30 jin per mu each time is sufficient.

3. During the full fruiting stage of cucurbits, both high-potassium and balanced fertilizers should be used

Unlike solanaceous fruit vegetables, after cucurbit vegetables enter the full fruiting stage, the growth of stems and vines does not weaken. If nutrients dominated by high potassium and low nitrogen continue to be used, it will cause poor nutrition in the stems and vines, thereby affecting future yield. Therefore, topdressing for cucurbit vegetables should alternate between high-potassium and balanced fertilizer types.

Generally speaking, for every two uses of high-potassium fertilizer, one use of balanced fertilizer should be interspersed in between. Cucurbit vegetables have high yields and large fertilizer requirements, so the amount used per mu each time is generally about 25-30 jin.

4. Properly control potassium fertilizer during the full fruiting stage of legumes

Compared with solanaceous fruit vegetables and cucurbit vegetables, legume vegetables have lower yields and lower nutrient requirements. After legume vegetables enter the peak pod-setting stage, although the demand for potassium fertilizer is relatively high, the amount of potassium used must be accurately controlled.

Because for the marketability of legume vegetable fruits, too much potassium easily causes seed bulging, resulting in lower marketability. Therefore, during the peak pod-setting stage, balanced fertilizer should be mainly used, interspersed with one use of medium-potassium or high-potassium fertilizer, generally 5-8 kg per mu each time.

II. What are the effects of over-fertilizing?

When there is too much nitrogen fertilizer, it is often found that leaf area increases and leaf color becomes dark green. When severely excessive, plant leaves are found to be thick and hard, with distorted leaves, reduced fruit, or twisted fruit and other salt damage symptoms.

When there is too much phosphorus fertilizer, chlorosis symptoms such as zinc deficiency, iron deficiency and magnesium deficiency appear, because after phosphorus fertilizer dissolves it combines with these elements in the soil, reducing their availability.

III. What effects will applying only high-potassium fertilizer produce?

During the full fruiting stage, vegetables should be fertilized in a balanced way, and high-potassium fertilizer alone should not be applied. It is recommended that vegetable growers make a scientific fertilization plan according to the soil fertility status and the amount of base fertilizer used. For plots where too much potassium fertilizer has been used, the method of watering with clear water and stopping potassium topdressing can be adopted to reduce the potassium salt content in the soil, and spray some foliar fertilizer that stimulates root and leaf growth to promote the vegetable plants' return to normal growth.