|STRIK, BERNADINE - Oregon State University|
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/18/2010
Publication Date: 1/12/2011
Citation: Bryla, D.R., Gartung, J.L., Strik, B. 2011. Evaluation of irrigation methods for highbush blueberry. I. Growth and water requirements of young plants. HortScience. 46(1):95-101.
Interpretive Summary: Over 145,000 acres of blueberries are farmed in the United States. Most of the acreage requires irrigation. We conducted a study to determine the best method to irrigate highbush blueberry. Plants were irrigated with sprinklers, microsprays, or drip. Data was collected during first 2 years after planting on uncropped plants and focused on identifying irrigation systems that improve growth of the crop during establishment. Irrigation was also applied at three different watering rates to identify the optimum rate of irrigation and to investigate the consequences of over- and under-irrigation with each system. Irrigation water requirements are usually much less during establishment than at maturity but are often considered more important, because even a small amount of drought or flooding at this stage may substantially increase the time for plants to reach full production and profitability. By the end of the second growing season, drip irrigation produced the largest plants amongst the irrigation methods with 42% less water than microsprays and 56% less water than sprinklers. Drip irrigation was the best and most efficient method to establish healthy highbush blueberry plants.
Technical Abstract: A study was conducted in a new field of northern highbush blueberry (Vaccinium corymbosum L. 'Elliott') to determine the effects of different irrigation methods on growth and water requirements of uncropped plants during the first 2 years after planting. The plants were grown on mulched, raised beds and irrigated by sprinklers, microsprays, or drip at a rate of 50%, 100%, and 150% of the estimated crop evapotranspiration (ETc) requirement. After 2 years, drip irrigation at 100% ETc produced the most growth amongst the irrigation methods with 42% less water than microsprays and 56% less water than sprinklers. Drip also maintained higher soil water content in the vicinity of the roots than the other methods but reduced growth when plants were over-irrigated at 150% ETc. Only 570 mm of irrigation water, or the equivalent of 1320 L per plant, was required over two seasons to reach maximum total plant dry weight with drip, while 980 mm or more water was needed with sprinklers and microsprays. Consequently, irrigation water use efficiency, defined as the difference in plant biomass produced under irrigated and rain-fed conditions divided by the total amount of irrigation water applied, was significantly higher with drip than with the other irrigation methods, averaging 0.41 g of total dry weight per liter of drip irrigation. In terms of both growth and water use, drip irrigation was the best and most efficient method to establish the plants.