This is very relative, but in general it's related to the type of environment the plant inhabits and its physiology. If it's a dry environment plant, for example, normally the water requirements for its growth are not very extensive, it will be able to develop well with low amounts of water because they have specific features to tolerate certain stresses. However, it's important to supply these resource with a certain regularity in the first months of life for a better survival. In the experiment of restoration of areas in state of desertification that my laboratory run in the Caatinga dominium, we supply the plants with water in a vegetation house for 30 min/twice a week via sprinkling for at least four months and the seedlings are able to develop very well before being transplanted into the field. If your plants are of a more humid environment, they may need water more regularly. You have to understand their physiological requirements to know how much water they'll need. If you do an experiment with your species with different water amount treatments, you'll be able to reach a conclusion more rapidly. :)

Not exact but certainly you can get idea about the water requirement of plants.

1. Fast growing habit v/s Slow growing

2. Large size v/s Small size

3. Thick leaves v/s Thin leaves

4. Small sized leaves v/s Large sized

5. Tropical, Subtropical ecology v/s Arid ecology

6. environmental condition like temp. humidity and light intensity etc.

considering these factors you can decide the quantity and frequency of watering.

Yes, we can easily determined the amount of water required for the plant growth by estimating the water use efficiency. You can also determine it by plant physiological and morphological characteristics.

It will depend on the type of plant, the size of the plant, type of soil and the surrounding environment.

How much water do your plants really need?

https://www.greenhousemag.com/article/gmpro-0310-water-plants-automating-irrigation/