Matters needing attention in soilless cultivation of flowers, occurrence trend and control of flower diseases and insect pests in July

According to the investigation of Lunjiao, Beijiao, Chencun and Daliang flower production bases and greening sites, flower diseases and insect pests occurred moderately and locally in July, mainly anthracnose, powdery mildew, virus, soft rot, whitefly, leaf miner, sugarcane flat moth, thrips and so on. In addition, leaf spot, Fusarium wilt, powdery mildew, nematode disease, aphids, red spiders, purple butterflies, Spodoptera litura and so on occurred in different degrees.

I. occurrence trend of flower diseases and insect pests

Anthrax: it is expected to occur moderately and locally, causing damage to orchids, cockscomb, Michelia and other shady plants.

Powdery mildew: it is expected to occur moderately and locally, causing damage to solar plants such as Jiuli incense and chrysanthemum.

Virus disease: it is expected to occur moderately and locally, causing damage to shady plants such as orchids and white palms.

Soft rot: it is expected to occur moderately, causing damage to shady plants such as orchids and white palms.

Whitefly: it is expected to occur moderately and locally, causing damage to shady plants such as gerbera and cockscomb.

Leaf miner: moderate and local weight is expected to occur, causing damage to plants such as potted tangerines.

Sugarcane moth: it is expected to occur moderately, causing damage to rich trees, Brazilian wood and other plants.

Thrips: it is expected to occur moderately, causing damage to orchids, banyans and other plants.

II. Basis

1. Base number of disease sources.

According to the investigation, the average diseased leaf rate of anthracnose, powdery mildew, virus, soft rot, whitefly, leaf miner, sugarcane flat moth and thrips were 25.8%, 24.7%, 17.5%, 6.3%, 224, 136, 54 and 207 respectively.

2. Variety and cultivation

Planting is too dense, too much watering, poor ventilation, high temperature in the shade shed, and lack of ventilation, which is the hotbed of shade plant diseases.

3. Weather conditions

The average rainfall in June is more, and the temperature is the same as in previous years. According to the forecast of the meteorological station, affected by tropical disturbances in July, there will be heavy rain to torrential rain, which is conducive to the occurrence of diseases and insect pests.

III. Opinions on the prevention and control of flower diseases and insect pests

Timely removal of diseased plants and diseased leaves, centralized destruction, reasonable management of fertilizer and water, and reduce the spread of pathogens. Pay attention to the ventilation of the greenhouse, control the temperature and humidity in the greenhouse, and restrain the occurrence and spread of the disease. The chemical control of flower diseases and insect pests is as follows:

1. Prevention and control of anthrax: 70% thiophanate methyl wettable powder (methyl thiophanate) 1000-1500 solution can be selected; 65% zinc wettable powder 600 solution can be sprayed and sprayed again every 7-10 days. Anthracnose that occurs on other flowers can be prevented and treated in the same way.

2. Prevention and treatment of powdery mildew: 50% thiram wettable powder can be sprayed with 500mm 800 times liquid spray at an interval of 7 days for 3 times in a row; 1500 times thiophanate methyl wettable powder (methyl thiophanate methyl) and 1500 times thiophanate methyl wettable powder.

3. Prevention and control of virus disease: enhance plant resistance; on the basis of eliminating leaf piercing insects (aphids, shell insects), spray 8% Ningnanmycin water agent (Shikeduke) at the initial stage of the disease.

4. Prevention and treatment of soft rot: at the initial stage of the disease, 72% agricultural streptomycin sulfate soluble powder 3000 × 4000 times, 14% ammonia copper solution 350x, 30% copper succinate wettable powder 500x600 times, 4000IU/ micro-liter Bacillus thuringiensis suspension 500x solution, sprayed once every 7 to 10 days, continuous prevention and treatment for 3 times.

5. Control whitefly: 25% thiazine water dispersible granule 16g/ mu; 1.8% avermectin EC 1000 times; 3% acetamiprid EC 80ml / mu, applied in the initial peak period of Bemisia Tabaci.

6. Control leaf miner: you can choose 25g / L deltamethrin EC (enemy killed), 40% isocarbophos EC 800,400 times, 18% insecticidal double water agent 1000 times, it is best to spray in the evening (because adults often mate and lay eggs at night).

7. Control of sugarcane moth: 20% fenpropathrin EC 1500-2000 times liquid can be used to brush the trunk, drench the trunk and spray, once every 10 days, and then gradually extended to once a month; it can also be injected directly into the affected site with a syringe.

8. Control thrips: choose 40% dimethoate EC 800 times 1000 times, Regent 2500 times, acephate 30 times 1000 times, 98% Shamindan soluble powder (Badan) 1000 times, 2.5% rotenone EC 300 times 500 times, 45% malathion EC 3000 times 4000 times spray.