Citrus
Citrus is sensitive to Cl accumulations in the soil as are many tree and vine crops. Therefore, caution should be advised whenever considering the use of a Cl-containing fertilizer. The clear choice is SOP or other non-Cl sources when there is a problem of soil salinity (Zehler et al., 1981)

Blight of citrus appears to be worse with a combination of low tissue K and high tissue Na and Cl. Healthy trees in a 35-year old commercial grove contained 1.45 percent K, 895 ppm Na and 568 ppm Cl in leaf tissue compared to 1.02 percent K, 1,586 ppm Na and 947 ppm Cl in blighted trees (Wutscher and Hardesty, 1979).

California has established interpretive guides for S and Cl in leaves of mature Valencia and Navel oranges (Table 1). These values are applicable to grapefruit, lemon, and probably other commercial citrus varieties as well (Embleton et al., 1983).

Table 1:
Leaf analysis guide for diagnosing nutrient status of mature Valencia and Navel orange trees.