(10-22-2021, 08:19 PM)Jags Wrote: Also, you use  6” of water in your post.  Is that normal for a crop?  I understand different plants take different amounts of water.  Some more, some less. I know over here with our sandy soils 6” of rain in a short period would flood a bunch of areas around town, yet subside over a few days.  Watching the news, we see droughts then heavy rains in Ca then hear about landslides.  So how many inches do you normally supply to the grapes in any given timeframe?  Secondly, do you find the irony is supplying so much water to a grape only to dehydrate it to make raisins?  Wouldn’t it be nice to poorly water the grapes to produce the final product off the bat?

Ha, I just randomly said 6. 

So UC Davis will put out that reference ET number each week. What they do is give a weekly forecast for the upcoming week, and the actual amount used the previous week. So I take that weekly forecast and I run water on M, W, F, Sat too add up to the weekly total. So early in the season like April, I was using .25 acre-inches a week, so I'll calculate the total pump hours needed for that and divide it by the 4 days. In July I got up to 1.5 acre-inches a week. By mid August the water is off until I finish harvesting. Then hopefully after harvest I'll only need one or two days of water before we get some rain and thats it for the year until next April or so. 

That landslide stuff that year hear on the news is usually just rich people with cliffside houses in Santa Monica lol. Highway 1 gets a lot too. The Valley where I live is flat as can be because our irrigation canals are gravity fed. Between the two ranges, basically 4 million acres or so slopes a mighty 1 degree. I farm right against the San Joaquin River though, so sometimes I get a little more water than I bargained for. 

Never really thought or raisins that way but you're right, it is a little ironic. I know people that do severely restrict water (very popular for wine grapes) but for a bulk grower like me it's a little self defeating because in vines you actually grow two crops at once. Too little water this year can really hamper what you start with the following season.

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