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Submitted to: Blueberry Research Extension North American Workers Conference Proceedings
Publication Type: Proceedings Publication Acceptance Date: 5/6/2006 Publication Date: 6/4/2006 Citation: Bryla, D.R. 2006. Comparison of irrigation methods for establishing highbush blueberry. Proceedings of the 10th North American Blueberry Research & Extension Workers' Conference. p. 47-54. Interpretive Summary: Blueberries need irrigation for profitable commercial production in the U.S. Pacific Northwest. However, little is known about the water requirements for growing blueberry in the region, which makes it difficult to accurately schedule irrigations. Information is also lacking on the best irrigation methods for this crop. Therefore, we initiated a study in 2004 to compare the water requirements for growing blueberry with overhead sprinklers and drip, and to determine which method produces the most growth after planting. We also examined the possibility of using microspray (a.k.a. micro-jet or micro-sprinkler) irrigation. Although microsprays are not commonly used for commercial blueberry production in Oregon or Washington, researchers in Chile found that production was higher with microsprays than with drip. Our study in Oregon demonstrated that drip irrigation was the most beneficial method for establishing blueberry, provided plants are healthy. It also illustrated the potential risks of using drip when plants are infected by root rot fungi. Our next step, as the field matures, is to start cropping the plants and begin examining the effects of different irrigation methods and scheduling rates on fruit production in blueberry. Technical Abstract: A study was done to compare seasonal water requirements of newly-planted blueberry plants irrigated by two methods typically used in Oregon and Washington, overhead sprinkler and drip, and to determine which method produces the most growth during orchard establishment. We also examined the possibility of using microspray irrigation. Two cultivars, ‘Duke’ and ‘Elliott’, were irrigated by each system at 50, 100, and 150% of the estimated crop evapotranspiration requirement (ETc). During the first two years after planting, plants irrigated by microsprays required 12-36% more water as those irrigated by drip, while those irrigated by sprinklers required 117-138% more water. Interestingly, drip significantly increased growth in ‘Elliott’ compared to sprinklers and microsprays, but significantly decreased it in ‘Duke’. The benefit of drip in ‘Elliott’ was likely due to higher soil water content in this treatment, which probably enhanced plant water status over sprinklers and microsprays. However, in ‘Duke’, higher soil water content with drip increased the incidence of Phytophthora and Pythium root rot, which then led to weakened and smaller plants. Growth was similar in plants irrigated by sprinklers and microsprays in both ‘Duke’ and ‘Elliott’. |
