Common Pests and Diseases at Each Grape Growth Stage: Spraying and Control Timing
Grape is a very common cash crop, and many people grow grapes. But grape pest and disease problems give many fruit growers a headache. Let's take a look below at which common pests and diseases occur at each grape growth stage, and what to spray.
1. Bud break stage
When the winter buds swell but have not yet turned green, spray 3-5°Be lime sulfur mixture to further reduce the number of overwintering pests and pathogens. For orchards with severe disease the previous year, spray once more with 1-2°Be lime sulfur mixture or a copper formulation from the woolly bud to green-tip stage.
2. After sprouting to before flowering
2-3 leaf stage: mainly control green plant bug, once every 7-10 days, spraying 2-3 times in succession. Optional pesticides include: 70% imidacloprid water-dispersible granules 8000-10000 times, 10% beta-cypermethrin emulsifiable concentrate 2000-2500 times, 1.8% abamectin emulsifiable concentrate 3000 times, 1% matrine 1200-2000 times solution.
Inflorescence separation stage (8-10 leaf stage): this is the period of rapid increase in various pathogens and the suitable control period for rachis blight, gray mold, black pox, and anthracnose. Protective fungicides are mainly used; sprayable agents include: 80% mancozeb 600-800 times, 70% metiram water-dispersible granules 600-800 times, 70% propineb wettable powder 400-600 times, 80% Bordeaux mixture wettable powder 400-600 times, 78% Kebo wettable powder 600 times solution. In years with more rain, mix fungicides with protective agents, such as 80% mancozeb 600-800 times plus 10% polyoxin wettable powder 1200-1500 times solution.
3-5 days before flowering: this is an important control period for many pests and diseases; combining protective fungicides with systemic fungicides is recommended. For protective fungicides, choose the earlier Kebo, Bordeaux mixture, mancozeb, and 70% thiophanate-methyl wettable powder 800-1000 times solution. For therapeutic agents, choose: 50% iprodione wettable powder 1000-1200 times, 50% procymidone wettable powder 1000-1500 times, 50% fludioxonil wettable powder 4000-5000 times solution.
3. After petal fall to before cluster closure
2-3 days after flowering: this is the key period for controlling gray mold, rachis blight, white rot, and black pox. Combining protective fungicides with systemic fungicides is recommended. Choose agents safe for young fruit; do not choose wettable powder formulations, but choose water-dispersible granule or suspension concentrate formulations. Protective fungicides that can be used: 60% pyraclostrobin · metiram water-dispersible granules 1000-1500 times, 10% difenoconazole water-dispersible granules 2500-3000 times solution. Therapeutic agents for gray mold: 40% pyrimethanil suspension concentrate 1000 times, 50% vinclozolin wettable powder 500 times, 10% polyoxin wettable powder 1200 times solution.
Second spraying after flowering: 12-15 days after petal fall is the key period for controlling white rot, downy mildew, and anthracnose; broad-spectrum protective fungicides are recommended, and optional agents include: 25% azoxystrobin suspension concentrate 1000-1200 times, 68.75% oxathiapiprolin · mancozeb water-dispersible granules 1000-1500 times, 70% metiram water-dispersible granules 600-800 times solution.
Before cluster closure (generally also before bagging): the key targets are anthracnose, white rot, gray mold, downy mildew and other diseases. Use protective fungicides together with systemic therapeutic agents. Optional protective fungicides: 60% pyraclostrobin · metiram water-dispersible granules 1000-1500 times, 25% azoxystrobin suspension concentrate 1000-1200 times solution. Optional therapeutic agents: 50% boscalid water-dispersible granules 1000-1200 times solution.
4. After cluster closure to before veraison
Generally apply agents 1-3 times; once the rainy season begins, focus on controlling downy mildew on leaves, applying Bordeaux mixture or other copper formulations and other protective fungicides mixed with systemic therapeutic agents to prevent a downy mildew outbreak. Fungicides for preventing downy mildew include: 1:(0.5-0.7):200 Bordeaux mixture, 77% Duoning (copper calcium sulfate) wettable powder 600-800 times, 80% Bordeaux mixture wettable powder 400-600 times, 70% propineb wettable powder 400-600 times, 70% metiram water-dispersible granules 600-800 times, 68.75% oxathiapiprolin · mancozeb water-dispersible granules 1000-1500 times solution. Fungicides for treating downy mildew include: 50% dimethomorph water-dispersible granules 2000-2500 times, 72% cymoxanil · mancozeb wettable powder 600-800 times, 90% triethyl phosphonate aluminum wettable powder 600-800 times, 69% dimethomorph · mancozeb water-dispersible granules 600-800 times, 66.8% propineb · cymoxanil wettable powder 700-1000 times, 58% metalaxyl · mancozeb wettable powder 600 times solution. Note that therapeutic agents must be used in rotation to avoid resistance.
5. After veraison to maturity
Generally apply agents 2-3 times, focusing on controlling all fruit diseases such as white rot, anthracnose, sour rot, and gray mold. The last application must be more than 20 days before harvest. Continue spraying copper formulations and other protective agents; you can also choose 10% difenoconazole water-dispersible granules 2500-3000 times, 70% thiophanate-methyl wettable powder 800-1000 times solution. When white rot occurs, spray systemic therapeutic agents: 20% difenoconazole 4000 times or 40% flusilazole 8000 times solution; when anthracnose is found, rotate systemic therapeutic agents: 10% Meian aqueous solution 800 times, 50% kresoxim-methyl 3000 times, or difenoconazole.
6. After harvest to leaf fall
Mainly use 1:(0.5-0.7):200 Bordeaux mixture, spraying 2-3 times depending on the year's disease occurrence. After leaf fall or winter pruning, clear fallen leaves and pruned canes from the field, clear tendrils, canes, and petioles from the trellis, peel off old bark, process with a shredder and pile for fermentation into compost or dispose of centrally, and immediately apply lime sulfur mixture or Bordeaux mixture to reduce the overwintering base of pests and diseases, laying the foundation for pest and disease control the following year.