Salinity Management in Avocado Orchards

Avocado is one of the most salinity sensitive crops produced in California, but is commonly grown in areas having saline irriga-tion water (an EC greater than 0.75 dS/m and chloride>100 ppm). Resulting problems associated with high soil salinity and chloride toxicity cause reductions in fruit yield and tree size, lowered leaf chlorophyll content, decreased photosynthesis, poor root growth, and leaf scorching. During recent years, salinity problems with avocado have become increasingly common as the cost for irrigation water has gone up and the availability of low salinity water for agriculture has diminished. This has resulted in the need for improved knowledge on how to reduce soil salinity through proper irrigation manage-ment. This article reviews the causes for salt buildup in soils and the effects of chloride toxicity on avocado growth. Cultural practices including rootstock selection, irrigation water quality and timing, EC monitoring, and soil leaching methods are summarized with specific recommendations. California Avocado Society 2008 Yearbook 91:83-10