What causes rotten grapes after bagging?
Grapes are a very popular fruit, with a wide variety of cultivars in our country, and they are welcomed by many people. When growing grapes, careful management is required. Bagging is an indispensable technique in grape cultivation, a measure taken to prevent rotten fruit and improve fruit quality. However, sometimes grapes still rot after bagging. What causes this? Let's take a look together below!
1. Wrong bagging time
When bagging grapes, the first thing to pay attention to is the bagging time, which has a great influence on the effect of bagging. Generally speaking, it is better to bag grapes early, but not too early. It should usually be done during the grape berry enlargement stage, when the effect of bagging is also the best. If bagging is done too late, some fruits will be infected with pathogens, and even spraying chemicals cannot completely eliminate them. After bagging, they will still be active on the fruit. According to experimental data, the rotten fruit rate for bagging during the enlargement stage is only 3%, while if bagging is delayed by three weeks, the rotten fruit rate can reach 18%.
⟦NL>2. Wrong bagging method
Some people choose to finish bagging within one week after spraying the grapes. In fact, bagging this way will have a certain impact on the effect of bagging. We should bag the grapes promptly after spraying, once the chemicals have dried, and it is best to finish bagging on the same day. If there is no rain and it is guaranteed that there will be no dew at night, then it can also be delayed to within two days. If the planting area is large, then it should be done in batches, but it must be ensured that bagging is done only after the chemicals have dried. If they have not dried, it can also easily lead to rotten fruit. When bagging, do not press the berries with your hands, and be sure to tie the bag opening tightly to prevent rain from soaking through.
3. Wrong pesticide application
Before bagging grapes, we need to spray the grapes for disinfection. If the timing of pesticide application is improper, it can very easily lead to rotten fruit after bagging. Note that you must not spray when there is dew, nor when the sunlight is strong or there is strong wind. It is best to finish spraying between 7-9 a.m. This can avoid dew, prevent excessive sunlight, and also leave sufficient time for bagging. Then control the amount of chemicals well, ensuring thorough and even coverage as well as the quality of the chemicals. Do not spray too much, and do not miss any areas.
4. Paper bag quality issues
There are now very many types of bags used for bagging fruit on the market, such as paper bags, plastic bags, and so on. Bagging grapes has many benefits: it can prevent the fruit from being contaminated, prevent bird damage and pests and diseases, and so on. It is very beneficial to grape yield and fruit quality. When choosing bags, we must not choose those plastic bags that are not breathable or water-permeable just to save money. High-quality wood pulp paper bags should be the main choice, because as long as the quality of the paper bag is slightly poor, it can very easily cause rotten fruit inside the bag.
The above is a brief introduction to what causes rotten grapes after bagging. That is all for today's introduction. This article is for reference only, and we hope it can help everyone!