What Pesticides to Spray After Bagging Grapes for Good Results

Bagging grape clusters is a technique used in grape growing that can give the fruit bright, lustrous color and improve coloring, among other advantages. So, what pesticides should be sprayed after bagging grapes?

1. What pesticides to spray after bagging grapes?

After grapes are bagged, the main disease to control is downy mildew. Pesticides that can be used include 2000-3000 times diluted 50% phoxim-cypermethrin emulsifiable concentrate or 1200-1500 times diluted 48% Lorsban, etc. If the infestation is severe, the bags can be removed before spraying.

2. What pesticides to spray before bagging grapes?

1. Before bagging, the orchard should be thoroughly sprayed with a fungicide, focusing on the fruit clusters. Wait for the spray solution to dry before bagging. First, soak the 6-7cm at the opening end of the bag in water to make it moist and soft, which makes it easier to cinch the bag opening. When bagging, first open the paper bag by hand so that it puffs up, then insert the entire fruit cluster into the bag from bottom to top. Then cinch the bag opening onto the cluster stalk and secure it tightly with the wire tie on one side. Leave 1-1.5cm of paper bag above the wire. When bagging, never rub the fruit cluster with your hands.

2. After spraying grapes, bag them promptly once the spray solution has dried, preferably completing bagging the same day. If there is no rain and no dew at night, complete bagging within two days at the latest. For large vineyards, work can be done block by block. Based on labor and bagging speed, calculate how many bags can be done in a day, and spray only as much as can be bagged. Never bag before the spray solution has dried, as this can easily cause fruit rot. Also note that when bagging, try to avoid touching the berries with your hands, and be sure to tie the top opening tightly to prevent rainwater from leaking in.

3. Do not spray when there is dew, strong sun, or strong wind. It is best to spray between 7 and 10 in the morning. Spray evenly; do not spray too much, and do not miss any spots. For trellised grapes, spray both sides; for trellis frames, also spray both sides of the fruit clusters. Use pesticides with good efficacy, such as mancozeb, thiophanate-methyl, DuPont Fusilade, etc. Never spray counterfeit pesticides. When spraying, choose a fine swirl disc for the sprayer nozzle to help ensure fine and even application.

After bagging grapes, if no pests or diseases occur, try not to spray; after removing the bags, generally no further spraying is needed either, but the progress of fruit coloring must be closely monitored.