Disease and pest control of broccoli

1. Downy mildew occurs all over the country, mainly harming leaves. It is easy to occur under the conditions of sudden cold and heat, rainy and high humidity. 7 ℃-13 ℃ was the most susceptible to disease, and the disease tended to stop at 25 ℃. Prevention and control measures: clean the countryside before cultivated land, reasonable close planting, half-high ridge cultivation as the main means, spray 75% chlorothalonil wettable powder 500-800 times liquid, or 65% Daimen zinc wettable powder 500-700 spray, or 1JV 215 300 Bordeaux solution. Once every 7-10 days, it has a better control effect.

two。 Sclerotinia sclerotiorum rarely occurs in North China, and once it occurs, spraying can be carried out as soon as possible. You can choose 50% topiramate 500 times, or 25% carbendazim 500 times. Or 0.2% Mel 0.3% Bordeaux liquid spray, once every 7 days, 2-3 times in a row, focusing on the base of the stem and the ground surface.

3. Black spot occurs in all stages and mainly harms leaves. Spread by wind and rain. 25% ℃-30 ℃ high temperature, rainy or dew, fog, continuous cropping low-lying land serious disease, control measures, avoid continuous cropping with cruciferous crops, seed disinfection from disease-free areas. Drug control, spray with 1000 times of Dysenamine solution at the beginning of the disease, once every 7-10 days, 2-3 times in a row, pay attention to stop the drug 15 days before harvest.

4. Black spot mainly harms leaves and petioles, low temperature and high temperature are easy to occur, the relative humidity is more than 85%, and the temperature from 17 ℃ to 20 ℃ is the most suitable condition. Prevention and control measures: clean the countryside, seed disinfection, increase the application of phosphorus and potassium fertilizer, reasonable close planting, high ridge cultivation, chemical control, use 75% chlorothalonil 500600 times liquid, or 50% carbendazim 1000 times liquid spray at the initial stage of the disease, once every 7-10 days, continuous spraying 2-3 times can control the development of the disease.

5. Pieris rapae were treated with 1200-1500 times liquid (0.1% washing powder as adhesive), and sprayed immediately after finding white butterflies in the field; 20% fenvalerate or 2000 times trichlorfon crystals could be sprayed when the field population density was high.

6. The diamondback moth, Plutella xylostella (1.8%) EC 3000 times liquid spray, or Weinong 1 70 ml, Shamimeiling 70 ml plus 50 L water spray can also control Noctuidae and many other pests.