Salinity and citriculture.

Soil salinity significantly limits citrus production in many areas worldwide. Although data on fruit yields in response to salinity are limited, they indicate that grapefruit, lemons, and oranges are among the most sensitive of all agricultural crops. Fruit yields decrease about 13% for each 1.0 dS m(-1) increase in electrical conductivity of the saturated-soil extract (EC(e)) once soil salinity exceeds a threshold EC(e) of 1.4 dS m(-1). Accumulation of excess Cl(-) and Na(+) can cause specific ion toxicities, but this problem can be minimized by selecting rootstocks that restrict the uptake of these ions. During the past two decades, numerous papers describing the agronomic and physiological responses of citrus to salinity have been published. This paper reviews these research reports and discusses differences in the response of citrus species to salt stress, the role of different rootstocks, the causes of salt injury, and the interactions of other environmental conditions or stresses with salinity.