So which type of pipe should you use for your retic?
When we install we use PVC in lawn areas and poly in garden beds. You can use PVC in garden beds too, but I like go have more flexible pipe in the garden both in form and in function
With poly you can use shrub sprays, microsprays or drippers, but when you use PVC you are limited to shrub sprays
In the lawn where you are less likely to make any modifications it is wise to use PVC. It is durable and harder to chop thru with a spade.