Common diseases and insect pests of flowers in spring

There are many diseases and insect pests of flowers in spring, and the more serious ones in April and May are as follows: aphids (greasy hibiscus), green peach, mulberry, rose, honeysuckle and so on are vulnerable to aphids. With the increase of temperature, it becomes more and more serious. It must be detected and prevented in advance.

Prevention and treatment methods: ① sprays 50% imidophos, 1200-1500 times water; a small amount of ② potted flowers can also spray 70% 100 times neutral washing powder.

Most of the red spiders on many flowers, such as jasmine, Fusang, asparagus, rose, dahlia and so on, began to do harm in early April. Prevention and control methods: a small number of potted flowers can often wash the front and back of the leaves with tap water or spray or dip in 100-150 times of batter water that has been boiled and cooled, and rinse again with clean water in a day or two, which can achieve obvious results.

Scale insects (flower lice) most of the scale insects of Magnolia, rose, yellow poplar and Haitong begin to hatch from mid-April to mid-May.

Control method: ① brushes off the insect body manually before hatching; ② checks frequently that when the temperature is more than 20 degrees Celsius, flowers, seedlings and some flowers that are prone to rot roots newly sown or sown in autumn, if the soil humidity is high, the control method: before ① sowing, the soil is evenly mixed with 70% pentachloronitrobenzene of 3-8 jin per mu. ② controls watering in the young stage of seedlings, so as not to make the soil too wet. When ③ first found diseased seedlings, 1% ferrous sulfate was irrigated, all 4-8 jin potions per square meter.

Rust begonia rust is easy to infect a large number after the rain in April and May: rose rust is infected when roses are budding; prevention and control methods: ① rose disease in time to sprout the first yellow disease buds removed and burned to eliminate the source of infection; ② sprayed 15% of trimethoprim in the initial infection period, mixed with water 700-1000 letters, the effect is obvious.

Powdery mildew of rose, impatiens and yellow mildew are mostly infected in May and June, and are easy to cause symptoms such as yellow leaves, withered leaves and twisted shoots in summer. Control methods: ① should pay attention to the ventilation and light transmission of flowers; ② should apply less nitrogen fertilizer and more phosphorus and potassium fertilizer; ③ spray 15% strychnine in the initial infection period, 700-1000 times of water.