Flowering and Fruit Set

Now that bud break has long passed us by and the vines have built up their leafy, vigorous canopies, one of the biggest changes you will see in the vineyard, and on the vines themselves, is the emergence of tiny clusters that almost resemble baby grapes.  In actuality, these are not grapes at all, but rather groups of flowers called inflorescence.  Unlike other flowering plants that require outside agents like birds or bees to pollinate, most cultivated grape varieties are hermaphroditic and possess both the female ovaries and male stamens required to self-pollinate.  However, even with this reproductive advantage, only about 50% of the blooming inflorescence will develop fruit, as these tiny flowers are very delicate and susceptible to forces like rain, wind, and frost.

Once the inflorescence start to bloom, fruit set will begin as soon as the individual flowers become fertilized.  A tiny seed will start to develop and a berry will envelop the seed to protect it.  This berry, as you probably can guess, is the grape.  It would seem almost obvious that as farmers we would want as much fruit set within the inflorescence as possible, but this is not exactly the case.  If too much of the inflorescence starts developing fruit, the resulting cluster can become too packed and condensed with grapes and can lead to a variety of fungal infections.  Conversely, if an inflorescence has poor fruit set, you will notice a distinct difference in the size of the berries.  Larger, fully developed grapes are called "hens", the smaller, undersized berries are called "chicks", and  berries that are green, hard and unripe are called "shot".

During the 2018 harvest the grape growing industry, as a whole, experienced incredible levels of fruit set which lead to an unprecedented amount of grapes for making wine.  As we gradually get ever-closer towards the 2019 harvest, it is almost guaranteed that this won't happen again.  With one of the wettest months of May on record in California, all the precipitation will certainly affect the fertilization efforts of the grapes.  What this ultimately means in terms of production and harvest yields is still undetermined, but don't be surprised if the 2019 vintage ends up a little short.  All of this just goes to show that we really can't control Mother Nature and what she has in store for any of us.  Part of the challenge of being a farmer is learning to pivot, adapt and roll with the punches.  If it were any different, it wouldn't feel natural.