Cucumber is bitter because it contains a bitter substance. Bitter element mostly exists in the shoulder near the fruit stalk, but the tip is less, so the root of cucumber is often more bitter. This bitter taste has the heredity of varieties, so the existence and severity of bitter taste often vary from variety to variety. Generally, varieties with dark green leaves are more prone to bitter gourd than varieties with light leaves. At the same time, ecological conditions, nutritional status and vitality of plants all affect the occurrence of bitterness, so even melons on the same plant have different degrees of bitterness, and root melons are often more bitter.
Bitter gourd is easy to appear in the following situations:
First, water and fertilizer are insufficient. Especially from planting to harvest, the water content in plants is too low, the juice concentration in liquid cells is high, and the relative content of tetrandrine increases.
Second, there is not enough light. When the light is insufficient, the photosynthetic capacity of plants is weak and the photosynthetic products are few, which leads to malnutrition and weak growth of plants, and it is easy to form and accumulate tetrandrine.
The third is low temperature. During the period of low temperature and low sunshine, especially on cloudy days, the root growth of cucumber is not good. When the root system is damaged or its activity is blocked, it absorbs less water and nutrients, which leads to the slow growth of melon strips and the accumulation of more tetrandrine in the lower melon.
The fourth is high temperature. In early spring, when cucumber in greenhouse enters the late growth stage, more bitter elements will be accumulated in the cucumber strips because the temperature is too high, or because the root system of the plant is aging, or because the soil humidity is high, the absorption function of the root system is weakened, and the temperature is too high at night, and the growth of the cucumber strips is slow.
Fifth, excessive application of nitrogen fertilizer. Excessive nitrogen nutrition in base fertilizer and topdressing can easily increase the concentration of tetrandrine in cucumber, and on the other hand, excessive nitrogen can easily lead to the plants growing in vain. When the melons sit irregularly, the melons on the lateral branches and weak branches are prone to bitter taste.
Six, intertillage roots are easy to bear bitter gourd. In early spring, in order to improve the ground temperature, intertillage is often carried out. Sometimes, the continuous elongation of roots is neglected, and more roots are injured in intertillage, which makes the ability of roots to absorb nutrients decline, and the nutritional status of plants is poor, which leads to the decline of cucumber quality.