Serious case of drought-stress.

Please describe the drip system:
- number of of drippers?
- placement of the drippers?

Whatever your setup, I seriously doubt 20 minutes 3 times a week is adequate. You can determine if you're supplying adequate water.

Put a trowel into the soil to determine this:
- How deep does is it moist?
- how far beyond the drip line is the soil moist?

Oh yes, in which city & state do you live in?

Oh boy. Jean's so right. This poor tree is parched. First, create a nice well around your tree at the canopy edge (drip line). Set your drips (4) at 12-3-6-9 and be sure the well will fill up well with the drip set to twice a week. This may take 30 to 60 minutes, depending upon the gph rating on your drip heads. Don't let the sprinklers hit the trunk. Citrus trees do not like to be in the path of sprinklers, they prefer long, deep waterings at the drip line, once or twice a week (unless you're in a very hot area of the country, or are on very sandy soil). And yes, helps to know where you are. It will let us know how much water your poor tree needs. Right now, it looks like it needs a lot. The good news - enough water will revive your tree, citrus are pretty resilient.

Patty S.

It was suggested "This may take 30 to 60 minutes,"

Perhaps much longer.

You need to check the soil after an irrigation to determine just how effective it is. Stick a trowel in the soil -- how deep is it moist? How far to the side did the moisture extend?

The soil of each garden/landscape is different from all others.
Every gardener must do the above how-deep-etc test to determine how long and how often to water.

Beyond that, likely 4 drippers is far too few for that tree.
Also 30 - 60 minutes far too brief a time.

Need to add -- no fertilizer until tree is returned to good health.

Another thing -- Remove all the fruit because the tree needs the resources to recover.

If you dislike that idea, consider this:
- You can have a crop of fruit that's likely dry inside, and either degrade the tree's health further or, worse yet, possibly lose the tree within several years.
- or
- You can give the tree a somewhat better chance of surviving by dumping the fruit now.

Your decision.

The length of time to water will be entirely dependent upon your drip head volume. If you have high volume drip heads, 30 to 60 minutes with 4 high volume drip heads will be more than enough time to fill up a LARGE well (does for me). I would recommend purchasing your drip components from either an irrigation or orchard supply company. That way, you can purchase serious commercial drip components that provide high gph ratings. And Jean is right, hold off on fertilizing until you see some recovery going on, and you know your root zone is getting fully watered, or you're going to injure the already compromised roots. And I agree with Jean, might as well pull off the fruit. It's probably ripe by now anyway, and due to the water stress, you may be surprised and end up with some very sweet fruit.

Patty S.

I should amend my comment to add that the other factor determining length of watering will also be your soil type - loam, sandy, or clay (or some combination). Forgot to mention that rather key piece of info :-) Even though my soil is mainly DG, it is dense in spots, so some of my trees will fill up quicker (not soaking in as quickly), and other trees look like the wells are not as full, but in fact it's more due to how quickly the water is percolating right in that spot, and not a factor of how much water it's receiving. Bottom line for you - water, water, more water! Nice big well, fill it with compost and worm castings, keeping away from the trunk, then set up your watering regime to make sure you're giving this tree enough water. And, you might consider topping some of the taller branches as well. Will help your tree recover, and will also encourage more lower growth where it's easier to pick.

Patty S.