Cultivation techniques of Tulip bulbs treated with 9 ℃

Tulips need a certain period of cold treatment, in its stems to be fully developed before flowering. If tulip bulbs are treated with low temperatures before normal winter, they can bloom earlier. This technique is called "forced cultivation". Different treatments can make them bloom between December and February. Bulbs need to be treated at different temperatures for different periods of time, and then cold treatment begins. The transition temperature is the temperature used after the flowers have fully developed until the beginning of cold treatment. The time of transition temperature treatment depends on the variety and generally takes 2 to 8 weeks. 20℃ is the best transition temperature, which has a good effect on flower quality and root growth. The process of fully treating dry bulbs with low temperature for a certain time before planting is called cold treatment process. There are two main series of tulip bulbs imported from China: bulbs treated at 9℃ and bulbs treated at 5℃. The effects of cold treatment are shorter flower stems, larger flowers, faster bud and root development, and fewer flower blooms.

After understanding the treatment process of tulip bulbs, you can choose different treatment bulbs for cultivation. The following is an example of tulip bulbs treated at 9℃ to introduce cultivation techniques.

Seed bulb source and preparation China's tulip seed bulbs are mostly imported from the Netherlands. In October of each year, we must select the varieties to be planted and issue orders in time. At the end of October or the beginning of November, the seed balls will be placed in a storage room at 5℃ for temporary storage.

The preparation of nursery beds is fully mixed with loam, peat and soil miscellaneous fertilizer in the proportion of 4:1:1 in the greenhouse, and then spread flat. The thickness is about 10 cm, and the top is covered with a layer of coarse river sand about 5 to 7 cm thick. The width of the strip nursery bed is generally no more than 3 meters, so as to facilitate the later management. The nursery beds are sterilized 10 to 15 days before sowing, usually by methyl bromide or fumigation.

The sowing time is generally between November 15 and December 15. Due to rooting problems and reduced quality, do not plant after December 15. Seed balls are peeled before sowing and then disinfected. Soak seeds in 0.2% carbendazim or 0.5% potassium permanganate aqueous solution for 10 to 15 minutes, soak in clear water for 5 to 10 minutes, take out and dry before sowing. Sowing density is 8 x 12 cm and depth is about 1 to 2 cm covering bulb tops. Irrigation immediately after planting to prevent drying and dehydration of the bulbs.

Post-sowing management keeps the soil moist and prevents drying and dehydration of the bulbs. The seed balls ejected from the sand layer due to root growth shall be replanted into the sand layer in time. Remove lateral buds. The day and night temperature in the greenhouse is controlled between 12℃ and 22℃, and the relative humidity does not exceed 80%. The greenhouse should be ventilated regularly. The growth of the seed ball and the temperature and humidity in the greenhouse should be recorded in detail.

Disease and Control

1. Damping-off flower stem or plant lodging. The reason is that the relative humidity in the greenhouse is too high, or the seed bulb roots are too poor, resulting in reduced water absorption. Control method: Do not have too low temperature in management, do not let plants grow too fast in high temperature, ensure normal root system, and avoid high relative humidity (more than 80%).

2. Blind bud water loss, petals remain green, white leaf tips, stamens and pistils dry, flowers can not fully open. The reasons are insufficient cold treatment, too high temperature during storage and transportation, too high relative humidity in greenhouse, incorrect watering method leading to root suffocation, etc. Control methods: In every link, we must strictly prevent the occurrence of the above phenomena.

3. A part of roots rot when slightly infected, and flowers wither when seriously infected. Infected roots usually turn waxy and brown the soil around them, eventually turning the entire root system brown. Caused by infection with pythium. Control method: disinfect the soil before planting. The heavily infected seed balls should be removed in time. Ensure good soil structure and drainage systems in greenhouse soils. For the first two weeks of planting, keep the greenhouse temperature at or below 10℃.

4. In the early stage of soft rot, the infected bulb tissue becomes soft and pink, and releases a special smell; in the later stage, the infected soft rot shows the phenomena of plant growth stopping, leaf tip turning yellow, flower dehydration, etc. Due to infection with pythium. Control method: Before planting, the bulbs should be fully disinfected and sterilized, and the soil should be disinfected. Ensure good soil structure and drainage systems in greenhouse soils. Remove infected plants in time and disinfect infected soil.

5. Water immersion green spots appear on flowers and leaves, and gradually turn into large white or brown spots, which can lead to plant development or hinder flowering in severe cases. Caused by grape mold infection. Control method: Remove the infected bulbs before planting, and disinfect the soil. The infected soil is routinely sterilized. Keep the leaves dry, especially at night. It is best to pour water directly onto the soil.