It is a mildew-like spot or "thorn". Caused by microorganisms: Microorganisms invade the peel and cause moldy spots and small particles. Eat with caution. Caused by gibberellin: caused by high concentration of gibberellin treatment, which is called "fruit thorns", which can be eaten with confidence.

1. Caused by microorganisms

During the growth process, black grapes will be invaded by some microorganisms. The spots on the black grapes may be caused by the entry of microorganisms. Symptoms of mildew-like spots and small particles are caused in the skin of summer black grapes.

2. Caused by gibberellin

During the growth process of black grapes, in order to increase the size of the fruit, it must be treated with gibberellin, and the small granular particles on the fruit surface The pimples may be caused by the high concentration of gibberellin treatment, which is called "fruit thorns". There is no need to worry about the problem of gibberellin residue. The period of gibberellin treatment is the peak flowering period, which is 40 to 50 days before the grape picking period. Eat with confidence.