Re: What causes black dots
The black dots you see on the fruit is probably a type of mold. Grapes are very picky about the type of climate they are is. Grapes do not like really moist and gloomy days. Your vines need to be in a place that they receive full sun and in a place at night that receives no light even from night lights. You can control the fungi your seeing on you grapes by spraying them with some sort of fungus spray. Check with your local farm supply store for the correct sprays. You will need to spray about every 2-3 weeks.