Several months ago I planted a row of blueberries in order to form an (edible) hedge. At the same time I installed an automatic watering system for these and the rest of my fruit trees and vegetable patches.
I used a variety of systems including mini sprinklers, drippers and soaker hoses for the different types of trees, shrubs and vegies. For the blueberries, I put in two drippers for each plant, one either side of the trunk about 20cm (8 inches) from the trunk and underneath a 1-2 inch layer of lucern mulch. The rationale for this was that since I will train these bushes to grow as a hedge, a dripper would work to sit under the hedge and apply water to the root zone, whereas a sprinkler would get blocked. I applied well rotted compost and acid loving plant poultry manure based pelleted fertiliser when planting, and added additional fertiliser 2 months after planting. The subsurface soil in my area is an acidic heavy clay, although the top 6-12 inches in the location of the blueberries is a more balanced imported garden soil. I am in Sydney, so we are currently in the middle of a hot, dry summer.
That is the background. My problem is that the blueberries are growing very slowly with little new growth and the tips (in some cases the 'tip' is up to half of the leaf) are showing a burnt reddish appearance and shrivel up and die. I found this question which appears to describe the same issue. One thing I noted is the suggestion to wet the entire root area. I also found on this site the comment
There is little lateral translocation of water and nutrients within the plant. This means that irrigation should moisten entire root zone, not just a portion.
Could my problem be that the use of two localise watering points means I am not getting water to the whole root zone? The worst case scenario would be that I'm over-watering some parts and under-watering others!
What would the optimal irrigation method for a blueberry hedge be?