Problems and Countermeasures in softening cultivation of Dutch Chrysanthemum in Winter

Dutch chrysanthemum, also known as Dutch chicory, Jikang vegetable, French bitter borage, is a biennial or perennial herb of Compositae, which feeds on the bud balls produced after fleshy root softening cultivation as the product. Dutch chrysanthemum bud balls are creamy, slightly bitter and sweet, to crisp to tender, can be used for raw food, or made into delicious appetizer salad. In particular, bud balls contain bitter substances that are not found in general vegetables, such as chestnut bark glucoside, wild lettuce, borage and mountain lettuce, which have the health care effect of clearing liver and promoting gallbladder, and have become the aristocracy of vegetables. Because the Dutch chrysanthemum bud ball needs secondary cultivation to form the product, among which the softening cultivation technology is difficult, and the problems such as fleshy root rot, bud ball rot, loose bud ball, small bud ball and turning green are easy to appear in the production. as a result, the output and quality of the products are greatly affected, the production potential can not be brought into full play, and the economic benefit is low. After years of production practice, the author puts forward countermeasures to solve the problems, and the implementation effect is very obvious.

1 the existing problems and causes

1.1 the succulent root rotted too late or the storage temperature after harvest was lower than 0 ℃, which caused the succulent root to suffer frost injury, or in cultivation, too long petiole was left at the top of the root and the soil moisture was too high, which could cause the succulent root to rot.

1.2 the main reason for bud ball rot is that there are wounds in the rhizome during cultivation, and the air humidity is on the high side, which is beneficial to the spread of bacteria.

1.3 when the temperature exceeds 21 ℃, the growth rate of bud ball is too fast, the bud ball is loose, and it is easy to form early bolting and spread. At the same time, the taste of bud ball is bitter and not crisp, and the quality is declining.

1.4 in the cultivation of small bud ball, the temperature of 10~15cm soil layer is below 6 ℃ for a long time, or the soil layer is dry, the air humidity is low, or the fleshy root is small, which will make the bud ball smaller and the yield lower.

1.5 during processing, the petiole at the top of the bulb without main buds was cut too short, causing damage to the growing point, thus softening the growth of bulbs without main buds and only lateral buds were produced in cultivation.

1.6 the bud ball turned green and softened the cultivation place, or the light was frequently opened in the cultivation, resulting in the bud ball turning green, the leaf ball scattered, and the quality deteriorated.

2 take measures

2.1 beware of freezing damage before severe frost and soil freezing, when the local minimum temperature drops to ~ 2 ℃, dig out the fleshy root in time, remove the root tip and lateral root, retain the fleshy root of the upper 20cm, pile the upper fleshy root with the root on the spot, the leaf faces outward, and the root faces inward, forming a steamed bread-shaped pile with a diameter of about 1m to prevent the fleshy root from freezing and losing water. After drying for 2-3 days, the wound healed, and then the fleshy roots were arranged according to the standard and stored in 0-2 ℃, waiting for softening cultivation.

2.2 the yellow leaves and old leaves of the plant should be removed reasonably, the petiole with 2~3cm length at the root neck should be retained, the upper leaves should be cut off, and the large and small roots should be stacked separately and softened separately so that the bud balls are of the same size. Note that the upper leaf stubble of the rhizome should not be too long or too short, too long is easy to rot during storage, stay too short, easy to hurt the growth point and can not form a commercial bud ball.

Before pre-disinfection and softening cultivation, 22% dichlorvos smoke agent 500g/ mu and 45% chlorothalonil smoke scavenger 250g/ mu were used to disinfect the environment, and then soak the roots in warm water of 50-55 ℃ to kill the heart-eating insect pupae on the fleshy roots; then the rhizome was immersed with 50% carbendazim WP500 times to inhibit the occurrence or spread of Sclerotinia sclerotiorum and prevent the rot of bud balls.

2.4 soil temperature has a direct effect on the bud ball of Dutch chrysanthemum. Generally, it can be softened at 4: 21 ℃, and the softening time varies with different varieties and temperatures. when the temperature is high, the time is short, and when the temperature is low, the time is long. When the temperature is low, the bud ball is brittle and tender, the bitterness is light, and the quality is good; when the temperature is high, the bud ball is bitter and not brittle. Generally speaking, it is appropriate to keep the soil temperature at 8-15 ℃ in 10~15cm. The temperature level is mainly achieved by adjusting the heating and covering ventilation of the softening place. For example, the temperature rise and fall of the solar greenhouse is regulated by the morning and evening of the grass cover, the opening and closing time of the vents of the plastic greenhouse film and the size of the seams.

2.5 the decay of succulent roots and bud balls with moisture control and anticorrosion is mostly related to the high temperature of the cultivation environment. In winter softening cultivation, the loss of soil water is less, as long as enough water is irrigated in the cultivation ditch, there is no need to water in the middle. After water infiltration, the fleshy root was buried to the root crown with fine soil code, and then covered with fine sand or sawdust 4~5cm. 2. 3 days later, wait for the water vapor in the ditch to dissipate and then build a double-layer black film, the film is 30~40cm from the root, do not accumulate water in the surface soil of the succulent root, or do not cover the film immediately after pouring the ditch, all these will make the air humidity in the cultivation ditch on the high side and introduce the rot of succulent root and bud ball. In softening cultivation, it is appropriate to keep the environmental relative humidity between 85% and 95%, and the level of air humidity can be adjusted by ground water spraying or night ventilation.

2.6 during the whole process, the light-forbidden softening place should be kept absolutely dark. After the cultivation ditch is covered with black film, the soil should be compacted all around, and the grass should be pressed at the same time to create a dark and moist softening environment. And to reduce the number of times to check the growth of bud balls during the day, so as to prevent the bud balls from turning green.