The risers of sprinklers may also interfere with machines on those fields that are machine harvested. The negative aspects of drip irrigation are the facts that dust cannot be washed off fruit, plants cannot be cooled by irrigation on hot summer days, frost protection is not possible, a cover crop cannot be irrigated, and maintenance to prevent emitters from clogging is more time-consuming and more difficult to monitor than with overhead sprinklers. For maximum efficiency of a drip irrigation system, growers should seek professional advice on water purification, equipment selection, and system layout to ensure uniform water distribution. Note that in hot, dry summers, many growers in the Pacific Northwest have not been able to supply drip irrigated blueberry fields with sufficient water for adequate renewal growth and maximum fruit size. Overhead irrigation works best under these conditions.
Some growers supplement drip irrigation with overhead systems.
This fact sheet is adapted from Oregon State University Extension Publication PNW215, Highbush Blueberry Production .