|Ehret, David -|
|Frey, Brenda -|
|Forge, Tom -|
|Helmer, Tom -|
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 30, 2012
Publication Date: March 1, 2012
Citation: Ehret, D., Frey, B., Forge, T., Helmer, T., Bryla, D.R. 2012. Effects of drip irrigation configuration and rate on yield and fruit quality of young highbush blueberry plants. HortScience. 47(3):414-421. Interpretive Summary: Most commercial blueberry fields in North America are irrigated throughout the summer. Many growers use drip irrigation in blueberry, to reduce water use and increase field access and food safety. Drip irrigation guidelines, however, are unavailable for blueberry in many regions. A 4-year study was done to determine the effects of four different drip configurations, including one or two drip lines and 12 and 18 inch emitter spacings, and two irrigation levels, moderate and heavy, on blueberry production in British Columbia, Canada. Yield was higher with irrigation than without it, but the benefit was later than expected (not until fourth year after planting) and was similar with one or two drip lines and either emitter spacing. Irrigation also produced larger fruit, preferred by consumers, and increased fruit nutrients. The study will continue as the plants mature.
Technical Abstract: A 4-year study was conducted to determine the effects of drip configuration and irrigation rate on yield and fruit quality in a new planting of highbush blueberry in British Columbia, Canada. Plants were grown in a silt loam soil on raised beds and were non-irrigated or irrigated using one line of drip tape suspended over the middle of the bed or two lines of drip tape located 19 cm from center on each side of the bed. The drip lines were attached to catch wires suspended at a height of 0.6 m and had 1 L/h in-line emitters spaced every 0.3 or 0.45 m for a total of four drip configurations. Water was applied by each drip configuration at two rates, a moderate rate of 5 L/plant per irrigation event and a heavy rate of 10 L/plant. Plants were cropped beginning the second year after planting. Rainfall was above normal the first 2 years after planting, and it was not until the following 2 years that soil moisture differed between irrigated and non-irrigated plots. Yield was not affected by irrigation until the fourth year after planting and was only higher with irrigation when 5 L/plant was applied, regardless drip configuration. The yield increase was partly due to higher fruit weight during the second of two harvests and was associated with a delay in fruit maturation. Fruit were also heavier, on average, with the higher rate of irrigation than with the lower rate, but fruit firmness was lower at the higher rate. Irrigation also affected mineral nutrition in blueberry. Leaf N, Ca, Mg, B, and Mn levels were lower with moderate and/or heavy irrigation than without it, while fruit K levels were higher with moderate irrigation than with no or heavy irrigation and fruit P and S were higher with moderate irrigation than with heavy irrigation. Irrigation also resulted in a change in anthocyanin composition in the fruit but did not affect antioxidants or total anthocyanin content.