What causes a grapevine to actually drip water from its vine?

In the past these grapes have produced nicely and looked great. This year the branches seem to 'snap off ' easily and then drip fluid (looks just like water-not sticky, no smell). The only difference this year is an automatic watering system- are they getting too much water?

Answers:
I don't really know what it is that you are describing, but the links below may help you to determine whether or not you are watering too much.
My zucchini plants get a lot of blossoms. Why don't I get any zucchinis?
  • looking for 6mil plastic for a greenhouse?
  • Wolf spiders camping in my house plants?
  • what type of plants grow the best under pine trees?
  • Need to reduce the weeds in the marshy lake in our backyard to take a canoe out-any safe ways to do it?
  • What is the best perennial flower for a hot area that thrives on neglect?
  • Will bare root holly hocks bloom in one growing season?
  • How do I kill reeds in my garden?
  • Does anyone know what giving of snake this is that I saw within my courtyard today?