Pest and disease control techniques for aphids, red spiders, scale insects, damping-off, rust and powdery mildew on flowers

In spring, the temperature turns warm then cold again, and the air humidity is high. At present, the occurrence of crop pests and diseases is at a moderate to severe level, and flowers also suffer from many pests and diseases. Generally, the following are more serious in April—May:

1. Damping-off

When the temperature reaches 20°C, newly sown flowers, saplings and some flowers prone to root rot are highly susceptible to damping-off when soil moisture is high. Control methods: 1. Before sowing, evenly mix 1.5—4 kg of 70% quintozene per seedling into the soil. 2. Control watering at the seedling stage and do not let the soil become too wet. 3. At the early stage of the disease, irrigate with 1% ferrous sulfate or 200—400 times 50% amobam solution, applying 2—4 kg of the solution per square meter.

2. Rust

Rose rust infects roses when the flower buds are about to open. Control techniques: 1. When roses sprout, promptly pick off and burn the yellow diseased buds that sprout first, to eliminate the source of infection. 2. Spray 15% triadimefon 700—1000 times solution at the early stage of infection.

3. Powdery mildew

Chinese rose powdery mildew and garden balsam powdery mildew mostly occur in May—June, and in summer easily cause symptoms such as yellow leaves, withered leaves and curved young shoots. Control methods: 1. Pay attention to ventilation and light transmission for the flowers. 2. Apply less nitrogen fertilizer and more phosphorus and potassium fertilizer. 3. Spraying 15% triadimefon 700—1000 times solution once at the early stage of infection is sufficient.

4. Aphids

Rose of Sharon, ornamental peach, hibiscus, Chinese rose and honeysuckle are all easily harmed by aphids. As the temperature rises, aphids also increase day by day. Control methods: 1. Spray after diluting 40% omethoate or 50% phosmet with water 1200—1500 times. 2. For a small number of potted flowers, a 70—100 times neutral laundry detergent solution can also be sprayed.

5. Red spiders

They begin to cause damage from early April to jasmine, hibiscus, asparagus fern, Chinese rose, dahlia and others. Control methods: 1. Spray 1000 times solution of fast-killing pesticide. 2. For a small number of potted flowers, frequently rinse the front and back of the leaves with tap water, or spray or dip with boiled and cooled 100—150 times flour paste water, then rinse once more with clean water after one or two days, which can achieve obvious results.

6. Scale insects (flower lice)

Scale insects on white magnolia, Chinese rose, boxwood and pittosporum mostly begin to hatch from mid-April to mid-to-late May. Control methods: 1. Before they hatch, gently brush off the insects by hand. 2. Spray 40% omethoate 1000—1500 times solution during the larval hatching period.