Can you change the sex of grapes?

One of the grape vines where i live here, i was told used to produce grapes. But it is now a male vine. So i was wondering if the person who said it used to grow grapes is crazy or if the vine changed sex, and if it changed sex, can i change it back, and if so how, also, how do i keep the others from changing sex? Thank you so much for any help with this...

https://permies.com/t/139134/male-female-grape-vine

Most grapes have both male and female on the same vine.  Perhaps something changed in the environment to prevent the grapes from setting?  

The thing we usually have problems with here is lack of water or sun.  Some trees are growing too much and shading the roots of the grapes.

You can graft new varieties onto the old roots if you think it’s a problem with the plant.  

This vine gets a ton of water, more than the other vines because its the first in line. It also gets more sun then the other vines.

When I first read your question I thought you were joking. Then I looked it up. You learn something new every day.


How to Tell a Male Grapevine From a Female Grapevine
By Karren Doll Tolliver
Updated July 23, 2012 1:39 p.m.

Grapevines reproduce sexually and the flowers on any given vine will be either male or female. Although growers propagate grapevines primarily from cuttings, it is possible to create a hybrid vine by pollinating female flowers with pollen from male flowers on a different plant. Cultivated grapevines are mostly hermaphroditic, which means that their flowers are both male and female, called "perfect" flowers. Although flowers on a grapevine are quite small, it is possible to tell the difference between male and female flowers with relative ease.

1). Inspect a single grapevine flower under a magnifying glass. Grapevine flowers have no petals and grow on stem clusters that will eventually turn into grape clusters.
2). Look for an array of several thin filaments radiating outward from the center of the flower. The top of these filaments will be small and bean-shaped. These filaments are called stamens, and the bean-shaped tops are known as anthers. If the anther is mature, you will see a dust-like coating of pollen on it. Since stamens are male flower parts, the presence of a stamen array tells you that the grapevine is male.
3). Look for a long, green, relatively thick protuberance in the center of the flower atop a vase-shaped node opposite the flower stem. This protuberance is called the style, with a sticky stigma on top, and the fat vase-shaped part is the ovary. Altogether, the style, stigma and ovary are collectively known as the pistil, which is the female flower part. The presence of a pistil indicates that the grapevine is female.
4). Check for the presence of both stamens and pistils. If the grapevine flowers have both male and female parts, the grapevine is hermaphroditic.

Maybe it's not stressed enough to produce fruit?  Fruit trees usually need some sort of stressor to give a good harvest.  

Hopefully, someone else can chime in.  We usually ignore our grapes except to harvest and cut them back to the main trunk each winter.  They are near the rain barrels so they get a bit of water, but there's also zero rain here in the summer, so they get to fend for themselves mostly.  We usually get a bushel or two off each plant, but I suspect the harvest could be way better if we gave them some love.  But not too much as the grapes my grandfather planted and watered diligently, with rich soil, etc,  never gave any fruit.  

Could you graft in scion(s) from a female or hermaphroditic vine? I'd think the resulting branches would still produce fruit, though the rest of that vine wouldn't. (If the vines at your place are all either male or female, no hermaphrodites, I'd still let this vine grow a branch or two of it's own, for pollination.)