Q.grapefruit tree
I plant my young 15 gal. Pomponello grapefruit tree two months ago. It started well for first month and now it is struggling to survive. Big leaves become yellow and dry. Tops are very weak and losing vigor. Whole tree looks like it is living on the last will. Is it infected by cancer or did I water too much? I watered every day in dry climate of Phoenix, AZ.

Certified GKH Gardening Expert
I would water more. Newly planted trees need a significant amount of water to establish. Try watering for longer periods and perhaps even twice a day if your soil is on the sandy side. Make sure to water deeply when you water to make sure the water gets deep in the soil to all the roots.

Thanks Heather,
Now I think that water and hot weather in Glendale AZ is the issue.
I think that the tree has enough water but it was still too hot air so I build some shadowing net cover over the this young crown. It is doing much better since.
Also I gave some citrus fertilizer to boost it. Well I have two factors now, but I think that the shadowing net is the best solution.
I water three times a week with deep watering of some 10 gal. with the drip.