This is the stage when the crop starts flowering. In corn, tassel emergence and pollen shedding takes place at this stage. Two to three days after pollen shedding, silk emergence takes place. At this stage, typically occurs 51-56 days after planting the corn seed, pollination between silks (female) and tassels (male) takes place.
This is a crucial stage of seasonal vine development. Tiny, self pollinating flowers that will form the new grapes bloom a few months after the beginning of the growing season. The success of the pollination depends upon the weather. Too much heat or heavy rain can impair pollination and lead to crop loss (also called " shatter"). Flowering is usually mid to late May in Napa Valley.