[planting technology] planting methods of African marigold

African marigold is a perennial herbaceous flower with perennial roots of Compositae, originally from South Africa. It has been introduced to China from abroad in recent years. It is loved by many people because of its beautiful appearance. Let's take a look at the planting method of African marigold.

I. growth habits of African marigold

African marigold is sunny, medium cold-resistant, can endure low temperature of-3 ℃-5 ℃, drought-resistant, loose and fertile sandy loam, performs better in moist, well-ventilated environment, strong branching and no need for coring. Early flowering, long florescence, low temperature is conducive to flower bud formation and flowering, mild climate can grow throughout the year.

2. Cutting propagation of African marigold.

1. Cutting method: when cutting propagation, the cuttings need to be planted in the rooting bed within 12 to 24 hours after harvesting, and if the time is too late, they need to be temporarily stored at the temperature of 7 ℃ to 10 ℃. The higher substrate temperature (20 ℃ to 23 ℃) is beneficial to the rooting of cuttings, and the temperature can be reduced after rooting. In addition, it can be dipped in rooting hormone to stimulate rooting in advance and improve the uniformity of rooting.

2. Cutting management: in the early stage of cutting (within 3 to 5 days), the spraying system needs to be opened for a long time, pay attention to prevent the wilting of unrooted cuttings and reduce the number of spraying at night. After rooting, fertilizer with the concentration of 75ppm to 100ppm can be applied. With the growth of the root system, the fertilizer concentration will gradually increase to 150ppm, while keeping the substrate moderately moist and avoiding oversaturation, which can not only prevent leaf yellowing caused by iron loss, but also reduce the occurrence of diseases.

III. Planting techniques of African marigold

1. Sowing method

[time] November-January.

[acupoint plate] according to the purpose of production, choose 72, 128 or 200 acupoint plate.

[methods] one seed per hole was sown on demand.

[Matrix] mixed in the proportion of peat ∶ vermiculite = 3 ∶ 1, the pH value was 6.2 ∶ 6.5, too low would lead to some metal elements (such as iron, sodium, etc.) poisoning. Drain the hole plate the day before sowing and set aside.

[covering material] covered with medium-grained vermiculite is beneficial to ventilation and water permeability. In order to ensure the temperature and humidity needed for germination after sowing, plastic film can be used to cover the hole plate.

2. The first stage of germination: from sowing to the emergence of cotyledons, about 6 min for 8 days. At this point, the plastic film can be removed.

[Matrix] the moisture content of matrix is 80% ±5%.

[humidity] 70%, 80%.

[temperature] 20 ℃-25 ℃.

3. The second stage of germination stage: from the exposure of cotyledons to the complete growth of cotyledons, the germination process is completed.

[temperature] temperature dropped to 18 ℃-25 ℃.

[substrate] keep it moist (with a water content of about 80%) and spray water on the seedling plate if necessary.

[chemical fertilizer] nitrogen, phosphorus and potassium compound fertilizer with 50-75ppm (EC = 0.8) was applied.

[light] No more than 25000lux, supplementary light can make the plant blossom earlier.

4. The third stage of germination stage: the first true leaf appeared until the seedling reached the standard specification (more than 4 true leaves, and the root system was full of holes).

[temperature] 18 ℃-20 ℃.

[moisture] the moisture content is moderate to avoid the matrix being too dry or too wet.

[chemical fertilizer] 150ppm nitrogen, phosphorus and potassium compound fertilizer was applied every 4 days (EC value was 1.0ml 1.2). Ammonium nitrogen fertilizer is beneficial to the growth of aboveground stems and leaves, and nitrate nitrogen fertilizer is beneficial to root development.

[light] same as stage 2.

[control] in general, the growth of African marigold plants is relatively robust, and overgrowth rarely occurs. In order to avoid excessive plant height of some varieties, B9 or PP333 can be used to control plant height at the end of the third stage.

5. The fourth stage of germination stage: the growth transition stage from the end of seedling cultivation to the sale of seedlings in the upper pot or pot.

[temperature] the growth temperature dropped to 17 ℃-18 ℃. From the beginning of this stage to flowering, the plant must go through a low temperature stage of 5 ℃-8 ℃ at night, which is beneficial to flower bud differentiation and flowering.

[water and fertilizer] Control moisture and excessive ammonium nitrogen fertilizer to avoid overgrowth of plants. Keep the substrate dry, strengthen ventilation and light, and enhance plant resistance.

6. post-pot management: the general African marigold nursery period is 10-12 weeks. The pot should be put on the pot in time after the end of pot breeding, otherwise it will lead to earlier florescence.

[substrate] mixed with peat ∶ vermiculite ∶ garden soil = 1 ∶ 1 ∶ 1, pH 6.2mur6.5.

[temperature] 18 ℃-23 ℃ during the day and 10 ℃-18 ℃ at night. If the temperature is too high, the flowers will become smaller, and some kinds of leaves may yellowing if the temperature is too low.

[moisture] the humidity of the substrate should be kept dry and wet, but do not make the substrate too dry and too wet. Too high humidity will lead to overgrowth or disease.

[chemical fertilizer] 150-200ppm nitrogen, phosphorus and potassium compound fertilizer (EC1.2-1.4) was applied.

7. Diseases and insect pests and their control

[pests] the cultivation and management of African marigold is simple, and there are few diseases and insect pests. The common pests are aphids, which can be controlled by spraying plants with 800 / 1000 times of 80% dichlorvos EC or 1000 times of net solution at a time.

[disease] the first common disease is rotten root, which is mostly caused by too much watering. It can be prevented by properly controlling water and keeping the matrix slightly wet and dry. Once it is found that the root is damaged, the basin should be changed and the matrix should be updated in time. The second is yellow leaves, the causes and control measures of yellow leaves are as follows: ① yellow leaves are mainly young leaves, often with spots. The reason is that the pH value of the matrix is too low, resulting in iron poisoning, so the pH value of the matrix can be adjusted by pouring appropriate concentration of lime water. If the temperature of ② seedling is too low, the night temperature can be increased appropriately. The insufficient application of ③ nitrogen fertilizer can increase the amount of nitrogen fertilizer appropriately.