Cultivation and management techniques of Impatiens africana

African impatiens ranks first in the application of herbaceous flowers in Europe and the United States. It offers a wide range of bright colors and is thriving and easy to manage. Suitable for dish box container, hanging basket, flower wall, window box and balcony cultivation. With more than 90% germination rate in the seedling plate, impatiens has always performed better in all the quality parameters of the seedling plate than other varieties, with the earliest flowering, the most abundant color and free branching. The plant is covered with a large area of flowers, creating a first-class flower bed and flower belt landscape, with a height of 20-25 cm. Leaves and flowers are very colorful and colorful, with a total of more than 40 colors. Under the background of the shade of the garden, the color is harmonious, symmetrical and meticulous, enriching and increasing the tonal depth of the flowers.

Cultivation and management

Loose and fertile sandy loam should be selected for basin soil, for example, it is better to use peat soil or rotten leaf soil mixed with sandy loam soil and some rotten cake powder or chicken manure on the market. This kind of soil is loose and fertile, which is more suitable for plant growth and conducive to the root growth of young plants. The seedlings can be divided once at the 2-leaf stage and planted in the flowerpot when they are about 4 cm high. When planting, it is best to choose cold clips and wet environment to help slow the survival of seedlings and early flowering. After the planting survived, the heart can be removed once to promote lateral branches, which is beneficial to multi-branch and multi-flowering. The growth of seedlings is slow, but the seedlings can blossom. With the growth of seedlings, fertilizer and water management should be strengthened, dilute organic liquid fertilizer or 0.3% compound fertilizer can be applied once every 10 days. The flower likes to be warm, moist and avoid strong light. It is best to place it in a place where there is half a day or 70% light every day, and water is often sprayed around it, so as to keep the plant plump and the flowers blooming continuously. Great African impatiens like half-day light conditions, and have successfully bred sun-resistant varieties, such as the exhibition series can also grow well in full-day light, so they are also suitable for planting in flower beds.

African impatiens are suitable for planting on family balconies or windowsills or in the shade of courtyard trees because of their preference for semi-shade. There is degeneration in the flowering of the old plant, and the plant is not beautiful, so the new plant should be replaced by cutting and attention should be paid to pruning.

1. Planting: the seeds are usually sown from March to April in spring. It can be sown in the seedbed or directly in the courtyard flower bed. The seedlings grew fast and should be planted in the garden at the beginning of June after one transplant. If the sowing is postponed, the seedlings will be pots and can blossom on National Day.

2, light and temperature: like light, but also resistant to shade, to receive at least 4 hours of scattered sunlight every day. Shade should be carried out in summer to prevent excessive temperature and hot sun exposure. The suitable growth temperature is 16-26 ℃, and the ambient temperature at flowering stage should be controlled above 10 ℃. Enter the greenhouse in winter to prevent the cold.

3. Watering and fertilization: irrigation should be made in time after planting. Pay attention to watering during the growing period, often keep the basin soil moist, especially in summer, but do not accumulate water and the soil is too wet for a long time. If Rain Water should pay more attention to drainage and waterlogging, otherwise the roots and stems are easy to rot. Fertilization should be diligent after planting, and special attention should be paid not to dry or wet. Never water wilting plants in the hot sun in summer. Especially in the flowering period, do not suffer from drought, otherwise it is easy to fall flowers.

4. Florescence control: if you want to postpone the florescence, you can sow seeds in early July. The method of heart-picking can also be used to remove early flowers and buds, so that the plant continues to expand, topdressing once every 15-20 days. more buds will be formed after September to make them bloom on National Day.

Pest control

Sometimes brown spot and powdery mildew occur, which can be controlled by spraying more than 50% carbendazim.

1. African impatiens powdery mildew

Symptoms the disease mainly occurs on leaves and shoots. It usually begins in June, and the leaves are covered with white powder layer after July. Subsequently, small yellow dots were formed in the powder layer, and the color gradually darkened, and finally showed dark brown. The pathogens overwintered in the remnants of diseased plants and seeds. The following year, when the environment is suitable, the germs spread by wind and rain. The peak period of disease is from August to September.

[control methods] planting is not too dense, proper ventilation, strengthen fertilizer and water management, enhance plant disease resistance. Remove diseased leaves and diseased plants and destroy them centrally so as to reduce the source of infection. During the onset of the disease, 15,000,1200 times solution of the wettable powder or 1000 times solution of the 70% methyl topiramate wettable powder were used for prevention and treatment. Avoid spraying at a high temperature above 32 ℃ to avoid drug damage.

2. Brown spot of African impatiens

African impatiens brown spot, also known as impatiens leaf spot. Symptomatic diseases mainly occur in leaves. The foliar spot is a light yellowish brown spot at first, then expands into a circle or oval, and then the center becomes light brown, the edge is brown, with inconspicuous rims. On the seriously diseased leaves, there are a series of disease spots, which causes the leaves to become withered and yellow until the plant dies. The pathogen overwintered on the remains of the disease and the fragments of soil and plants. The following year, when the environmental conditions were suitable, the germs spread by means of wind and rain. It is easy to get sick in the high temperature and rainy season.

[control methods] African impatiens prefers fertile sandy loam and is not resistant to waterlogging. Therefore, it is appropriate to plant sandy loam to facilitate drainage; potted African impatiens should be poured out in time after rain. Diseased leaves and plants should be destroyed at the end of autumn to reduce the source of infection in the coming year. The initial stage of the disease with 25% carbendazim wettable powder 300 times 600 times liquid, or 50% methyl topiramate 100 times solution, or 75% chlorothalonil 1000 times solution for prevention and treatment.

3. African impatiens blight

The symptomatic pathogen mainly infected the rhizome, the pathogenic part blackened or constricted, and white mildew appeared on it when it was moist. After the plant was infected, the leaves wilted and withered within a few days, resulting in the death of the whole plant. It overwinters mainly in the form of mycelium or sclerotia in the soil or in the sick and disabled body, and the mycelium camp in the soil is saprophytic and does not dormant. In the field, it is mainly transmitted by contact, that is, when the roots, stems and leaves of the plant come into contact with the diseased soil, it will be infected by the hyphae in the soil. Under the condition of water film, the healthy leaves in contact with the diseased part will be infected. In addition, seeds, farm tools and bacteria-carrying compost can spread the disease.

[prevention and control methods] after the diseased plants were removed at the initial stage of the disease, 75% chlorothalonil wettable powder was sprayed with 600x liquid, or 60% Fufu wettable powder 500x liquid, 20% methyl rifampicin EC 1200 times.