How to prevent and control grape diseases in the rainy season? A detailed guide to practical methods
The peak period for many diseases such as grape downy mildew, white rot and anthracnose is summer. The occurrence of downy mildew can cause grape leaf drop, dead branches, rotten fruit and even death. Therefore, China Agricultural Technology Network reminds you to strengthen vineyard management during the rainy summer season and to prevent and control diseases in good time. 1. Clean the vineyard: if in the vineyard...
1. Observe at all times and spot diseases Continuous cloudy and rainy weather with high temperatures and high humidity makes plants most susceptible to disease. You must go to the vineyard every day to observe it thoroughly. Spot diseases in good time and spray the right pesticide for the symptoms.
2. Do prevention work well and reduce disease
Use Bordeaux mixture as the main treatment, with other compatible chemicals: spray once before flowering with a 1:0.5:240 dilution, spray once after flowering with a 1:0.7:220 dilution, spray once during the grape swelling stage with a 1:0.7:200 dilution, spray once after grape harvest with a 1:1:180 dilution, and spray 1-2 times in autumn with a 1:1:160 dilution. In between, if white rot or anthracnose occurs, spray the right pesticide for the symptoms. These chemicals are mostly acidic, so the interval between them and Bordeaux mixture must be strictly controlled; this method gives very good disease control.
3. Apply supplementary fertilizer at the right time to strengthen the vines
The rainy season causes nutrient loss. According to the nutrient loss of the plot and the growth of the grapes, apply supplementary fertilizer at the right time, in small amounts and frequently. You can also apply foliar fertilizer, either combined with spraying or, when necessary, sprayed separately.
4. Cultivate and loosen the soil to increase permeability
After heavy rain or torrential rain, the surface soil in the vineyard becomes compacted, causing the grape roots to lack oxygen, lowering their resistance and making them prone to disease. Carry out a deeper cultivation once before the rainy season. During the rainy season, seize the gaps between rains to cultivate the vineyard and increase soil permeability.
5. Remove secondary shoots and change the environment
In the rainy season, grapes are most prone to excessive growth and secondary shoots appear very frequently. Pinch the tips and remove the secondary shoots in good time. For vines with too many new shoots, thin out some of them to improve ventilation and light penetration and increase stress resistance.
6. Clean the vineyard at the right time to suppress sources of disease
If disease occurs in the vineyard, the high temperatures and high humidity make it spread most easily. Clean the vineyard at all times. Remove diseased leaves, diseased branches and diseased fruit from the vineyard and bury them deeply or burn them. Clear weeds from the vineyard in good time; when cutting off diseased branches and fruit, wash the scissors frequently and disinfect them to prevent cross-infection.