Latest Analysis of the Causes of Grape Coloring Failure
Grape cultivation goes through several stages, and each stage has its own characteristics. The veraison stage is one of them; veraison is when the grape color turns from green to dark blue. Once veraison is successful, the grapes are basically almost ripe, but in many cases the color change stalls awkwardly, with the old not yet gone and the new not yet coming. Although failed coloring has little effect on the taste of the fruit, the appearance of the fruit will be rather unattractive, reducing its commercial value. So what are the causes that affect grape coloring? Details are as follows:
1. Too much fruit left on the vine
As the editor said in a previous article, many fruit growers, in order to increase grape yields, never carry out fruit thinning management on the fruit on the plants. In fact, this has a great impact on both the yield and quality of grapes, especially during veraison, when a large amount of nutrients is needed, but leaving too much fruit on the vine leads to an uneven distribution of nutrients within the plant. Some fruits even stop coloring halfway, showing a phenomenon of half green and half red. So we must thin the fruit reasonably; the number of fruits must not exceed the load the vine can bear, otherwise it will only be like drawing water with a bamboo basket, all in vain.
2. Light
During the stage from veraison to coloring, the grape's demand for light is very important; if sufficient light time is not provided at this stage, it will affect the grape's photosynthesis. This leads to insufficient accumulation of photosynthetic substances in the plant, making it impossible to ensure normal coloring of the fruit. Also, different grape varieties have different requirements for light time. So the method and duration of light should be determined according to the variety, and during the grape coloring period, sufficient light must be ensured so that the grapes can color smoothly and form a good appearance.
3. Fertilizer
Many fruit growers apply large amounts of nitrogen fertilizer during the grape veraison period, but in fact at this stage nitrogen fertilizer not only cannot promote grape coloring, but also affects yield and causes the grapes to turn green again. During the grape veraison period, we should apply heavy phosphorus and potassium fertilizer; phosphorus and potassium fertilizer can provide sufficient nutrients for grape coloring. Moreover, this veraison period is also the peak period of the grape's continuous fertilizer demand, and the amount of fertilizer applied should be determined according to the grape's growth condition and quantity. It must not be too much or too little; too much will also cause branch growth, which competes for the fruit's nutrients and is not good for fruit growth.
4. Water
Water is also very important during the grape veraison period. Although the grape's water demand increases during this period, there must absolutely not be any waterlogging in the orchard. Too much standing water in the orchard, or even soil that is too moist, will have a great impact on grape veraison. This is because during grape veraison, the respiration of the roots intensifies; if the soil is too moist, the roots have difficulty breathing. This makes it impossible for the roots to produce enough energy to absorb nutrients and provide for the grape's growth. And thus it also indirectly has a certain impact on grape coloring.
The above are the main causes of grape coloring failure. In fact, they are just some of the management tasks we need to do in cultivation. If these basic tasks are done well, there will not be much of a problem with grape coloring; the most important thing is still for everyone to strengthen orchard management. Alright, that is all for today's introduction. This article is for reference only. Thank you for reading and supporting us; you can visit our website to see more related information!