Weather-based scheduling and pulse drip irrigation increase growth and production of northern highbush blueberry

Authors: CARROLL, JESSE - Missouri State University; Orr, Scott; RETANO, ANDREA - Oregon State University; GREGORY, ALEXANDER - Oregon State University; LUKAS, SCOTT - Oregon State University; Bryla, David

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/9/2024
Publication Date: 3/26/2024
Citation: Carroll, J.L., Orr, S.T., Retano, A., Gregory, A.D., Lukas, S.B., Bryla, D.R. 2024. Weather-based scheduling and pulse drip irrigation increase growth and production of northern highbush blueberry. HortScience. 59(5):571-577. https://doi.org/10.21273/HORTSCI17527-23.
DOI: https://doi.org/10.21273/HORTSCI17527-23

Interpretive Summary: Cultivated blueberries often require lots of irrigation to achieve suitable and profitable production in most commercial operations. However, with warmer and drier weather conditions, increased water regulations, and greater demand for water by other sectors, growers are facing serious water-use limitations. In cooperation with faculty and students at Oregon State University, an ARS scientist in Corvallis, OR evaluated new practices, including weather-based scheduling and pulse drip irrigation, to better prepare the industry against future water uncertainties. Relative to using a conventional fixed irrigation schedule, weather-based scheduling reduced water limitations to fruit production and thereby increased yield and overall size of the berries. Pulse irrigation was likewise beneficial and resulted in more plant growth and larger berries than continuous irrigation. Thus, based on these results, growers who adopt the use of weather-based scheduling or pulse drip can expect to increase production with little to no impact on fruit quality, particularly when the plants are grown on light-textured soils in hot, dry climates.

Technical Abstract: Northern highbush blueberry (Vaccinium corymbosum L.) often requires frequent irrigation for commercial production, but irrigation is becoming increasingly challenging for many growers because of warmer and drier weather conditions, increased water regulations, and other water-use limitations. The purpose of the present study was to develop improved methods of irrigation to better prepare the industry against future water uncertainties. Treatments were applied for two years (2021-2022) and included a combination of weather-based or fixed irrigation schedules using continuous or pulse irrigation in a commercial field of ‘Draper’ blueberry in eastern Washington, USA. The soil at the site was a silt loam, and irrigation was applied using two laterals of drip tubing per row. Plants on a fixed schedule were irrigated once every 2-4 d for 12-13 h per application (set by the grower), while those on a weather-based schedule were irrigated according to daily estimates of crop evapotranspiration (downloaded from an automated weather station). In both cases, irrigation was applied in either a single continuous application on a given day or in 30- to 50-min pulses every 2 h, up to nine times per day, using the same amount of water as the continuous treatment. During the first year of the study, weather-based scheduling maintained higher stem water potentials in the plants and, on average, increased yield by 3.4 t/ha, berry weight by 0.14 g/berry, berry diameter by 0.4 mm, and fruit bud set by 4.3% when compared to fixed scheduling. Pulse irrigation also maintained higher stem water potentials and, on average, increased berry weight and diameter by 0.10 g and 0.4 mm, respectively, fruit bud set by 3.3%, and canopy cover by 2.4% relative to continuous irrigation. Yield and canopy cover were unaffected by any treatment in the second year, which was likely due to uncharacteristically cool and wet weather in the spring. However, weather-based scheduling continued to maintain higher stem water potentials and, when combined with pulse irrigation, increased berry weight and diameter by 3.7 g and 1.0 mm, respectively, relative to continuous irrigation at a fixed schedule. Pulse drip irrigation also increased fruit bud set by 5.1% during the second year. Overall, irrigation water use efficiency was higher with fixed scheduling and pulse irrigation than with weather-based scheduling and continuous irrigation, respectively. These results demonstrate the potential benefits of using weather-based scheduling and pulse drip in northern highbush blueberry, especially when the plants are grown on light-textured soils in hot, dry climates.