Grapevine Flowering Continued…

Grapevines have flowers? This phenological event goes unnoticed to an untrained eye. Flowering however plays a massive role for the viticulturist. The potential yield is strongly influenced within this 1-3 week period. The rather unspectacular flowers have petals (known as “caps”) which are fused around the reproductive organs (stamen, stigma and ovary). Below are some images from our vineyard this week.

Pre-Flowering:
DSCF1064Below, most caps have fallen however two can still be seen on the lefthand side of this future Riesling bunch. Notice the sticky Stigmas surrounded by the Stamen (made up of the pollen-carrying anthers supported by the white filaments). Once the stigmatic surface has been pollinated, the pollen grain germinates, sending a 2mm tube down to the Ovary which leads to fertilization and fruit set.

Flowering:

stigma new

At this point the grape grower receives the first indication of potential yield. The tiny berries have arrived and the vine begins to focus on the growth of these baby bunches.

Fruit Set:

DSCF1046