University of California

Buried drip irrigation reduces fungal disease in pistachio orchards


David A. Goldhamer
Themis J. Michailides
David P. Morgan

Authors Affiliations

D.A. Goldhamer is Cooperative Extension Water Management Specialist, Department of Land, Air and Water Resources; T.J. Michailides is Professor; D.P. Morgan is Staff Research Associate, Department of Plant Pathology, UC Davis, located at the Kearney Agricultural Center, Parlier. The authors gratefully acknowledge the assistance of the cooperators, Nichols Pistachio, especially Chuck Nichols and John Starling; and Scott Britten of Bennett and Bennett Irrigation, who designed the buried drip system. They also express appreciation to Mario Salinas, Chuy Salinas, Miguel Marquez, Lorene Boeckler, Kevin Tsuda, Vincent Bajman, Adam Sullivan, Martin Ruepp, Adrian Ziliani and Nancy Flory for their help in field monitoring and sampling. The California Pistachio Commission provided partial funding for this work.

Publication Information

Hilgardia 56(4):133-138. DOI:10.3733/ca.v056n04p133. July 2002.

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Alternaria late blight, a fungal disease affecting both leaves and fruit, can lower the quality of pistachios and reduce grower profit. High humidity in orchards increases the magnitude and severity of the blight infections. One cause of high orchard humidity is the evaporation of water from the soil surface, which in turn is enhanced by irrigation systems that wet the surface. In this study, we tested the use of buried drip irrigation, which reduces orchard floor wetting, to see how well it controlled the disease. When compared with a traditional flood irrigation system, the buried drip system reduced orchard humidity and dew duration and increased temperature. This significantly reduced leaf symptoms of the disease and fruit infection at harvest. Additionally, more shells split open with the buried drip method, resulting in a higher yield of marketable pistachios.


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Goldhamer D, Michailides T, Morgan D. 2002. Buried drip irrigation reduces fungal disease in pistachio orchards. Hilgardia 56(4):133-138. DOI:10.3733/ca.v056n04p133
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