Sunflower disease control
brown spot
Brown spot disease is very harmful to leaves, usually a round brown spot will be produced on leaves, which can be spread by rain, and residual bacteria will attach to leaves to cause disease.
Prevention of the disease can expand the spacing between plants, and good ventilation can effectively prevent the disease. During the onset, it is necessary to have less water and less fertilizer, and properly spray some drugs for prevention and treatment.
gray mold
Gray mold generally occurs in the middle growth stage, which will cause damage to the stems and leaves of plants. The germs of this kind of cake will stay in the soil, and when spring comes every year, it will fall on plants with the air in the air. When encountering this disease, it can be treated by fertilizing more and watering frequently, which can improve the disease resistance of plants. With a certain amount of drugs, the damage caused by diseases can be alleviated in a short time.
Seedling rot
It can cause pathological changes in plant roots and seedlings. At first, it presents lesions with different shapes, then the lesions will turn black, rot and the plants will die. The diseased parts of plants will produce white filaments, which can even penetrate the leaves.
The disease is transmitted by water, and the survival rate of bacteria is high in low-lying farmland, which is an important problem leading to plant infection. Usually, diseased plants can be carved out of their roots and properly watered to avoid water accumulation. At the same time, spraying with drugs can effectively treat this disease.
Cultivation techniques and disease control of asparagus
Asparagus, also known as Phyllostachys yunnanensis and asparagus grass, belongs to Liliaceae. Cultivated varieties include dwarf asparagus and big asparagus. Morphology and habit
Asparagus is a perennial herb vine with tender and slender stems and climbing. Roots slightly fleshy; The leafy branches are slender and tufted, shaped like feathers and spread horizontally; Leaves 3 mm -5 mm long, 6-12 clustered, cylindrical, with spiny scales; Flowers are small, bisexual, white, and bloom from February to March or June to July; The paddles are spherical and purple-black. Its bright green and lovely pinnate leaves stretch obliquely into sheets, like a floating Lv Yun. It is an excellent foliage plant, which is suitable for the decoration of halls, meeting places and desks, and is also an excellent foil material commonly used in flower arranging and flower baskets. It is also a very popular foliage plant with the largest sales volume in the flower market.
origin
South Africa is cultivated in gardens all over the world. Sexual preference is warm and humid, slightly resistant to shade, drought and frost, and the room temperature in winter is not lower than 5℃. I like to be born in loose and fertile sand.
Propagation and cultivation
Reproduce by sowing or dividing plants. First of all, seed plants should be cultivated for sowing and reproduction. Potted plants generally can't blossom and bear fruit, and seed plants should be planted indoors: plants that are healthy for 2 -3 years should be planted in the shade (mostly in the corner of greenhouse), and scaffolding should be set up to let them climb naturally. Sow mature seeds in shallow pots in spring and cover them with film or glass to keep the soil moist. It can germinate in about 30 days at 20℃-25℃. When the height of seedlings is 4 cm -5 cm and 8 cm-10 cm, they can be planted in pots or cultivation beds. Large plants that grow for 4 -5 years can be propagated by dividing plants, and clumps can be divided into 2 -3 plants in a pot or a clump. Keep it in the semi-shade until new leaves or plants grow. However, the newly separated plants are not perfect in shape and need to be maintained and shaped before they can be put on the market.
The soil of potted asparagus is mostly composed of humus soil, garden soil, sand, manure or phosphorus and potassium fertilizer according to the volume ratio of 5: 2: 2: 1. In the process of cultivation, the pot soil is required to be semi-dry and semi-wet. In summer, it should be placed in a semi-shady place and often sprayed on the leaves to keep the air humidity; The room temperature should not be lower than 5℃ in winter, otherwise it will die.
In order to produce a large number of leaf materials for flower arrangement, asparagus can be planted in a large area. Ground planting generally overwinters in plastic greenhouses and is covered with sunshade nets in summer to create semi-shady growth conditions for it. Ground planting requires the same soil as potted plants, but asparagus planted on the ground is flourishing and growing rapidly, so it needs to be erected in time to facilitate ventilation and high yield. At the same time, it should be trimmed in time to prevent bone meal or phosphate fertilizer from being applied before flowering. During the growth period of asparagus, the dilute liquid fertilizer with nitrogen and potassium as the main component can be topdressing every 10 day/time. Be careful not to infect the leaves when applying fertilizer, or spray the leaves after applying fertilizer to avoid the damage of fertilizer to the leaves.
plant diseases and insect pests
Asparagus and asparagus belong to Liliaceae, and the common pests and diseases are aphids in rainy season. When aphid damage occurs, 40% dimethoate and omethoate 1500 -2500 times can be sprayed. But in summer, it should be sprayed in the morning or evening when the temperature is low to avoid phytotoxicity.
Common diseases and control of Potamogeton rubrum
Common diseases of Potamogeton rubrum
There are three common diseases of safflower, namely anthracnose, damping-off and mosaic.
anthrax
The main symptom of anthracnose in safflower succession is black spots on leaves. Because the color of safflower succession is red, the black spots on the red leaves are very conspicuous, and its main harm is that it will cause deciduous leaves. Actinobacillus is the pathogen of anthrax, mainly in May every year. In June, the pathogen overwinters on the diseased leaves, leading to the next year's disease.
damping off
Rhizoctonia solani is the most serious disease in the seedling stage of plants, but this disease will accompany the plants all their lives, mainly in the roots of plants, where black spots will appear and be submerged, and then the epidermis will fall off from the xylem, leading to plant death.
mosaic disease
Mosaic disease is a disease caused by virus, which makes the leaves of plants turn gray and white.
Prevention and control methods of safflower grafting disease
anthrax
Once the diseased leaves are found, they should be treated immediately, destroyed to prevent reinfection, improve drainage conditions, give more sunlight to plants and create a good ventilation environment, and then treated with drugs.
damping off
Plant with new soil, change the soil frequently and disinfect the soil. If it is found that the diseased plant is destroyed in time and does not give it a chance to infect other plants, it will be treated with drugs.
mosaic disease
Drug therapy.