from: Reprinted Perspectives on new crops and new uses. 1999. J. Janick (ed.), ASHS Press, Alexandria, VA.
Salinity Effects on Growth, Shoot-ion Relations, and Seed Production of Lesquerella fendleri
Catherine M. Grieve, Michael C. Shannon, and David A. Dierig* Lesquerella fendleri (Gray) S. Wats., a native of the arid and semiarid regions of southwestern US, has been proposed as an important industrial seed oil crop (Thompson and Dierig 1988). Intensive breeding and agronomic research efforts at the US Water Conservation Laboratory have been directed towards domesticating and commercializing the crop (Dierig et al. 1993; Coates 1994; Brahim et al. 1996; Dierig et al. 1996; Nelson et al. 1996). Information on the management of lesquerella under saline conditions is limited to a two-season (1993 4 and 19945) field trial conducted by Leland E. Francois at the Irrigated Desert Research Station located at Brawley, CA (Grieve et al. 1997). Six salinity treatments were imposed by adding NaCl and CaCl2 (2:1 molar ratio) to Colorado River water. Electrical conductivities of the irrigation waters (ECi) ranged from 1.4 to 10.0 dS m-1. Both biomass production and seed yield were significantly reduced by salinity, although salt stress had no effect on either the content or the composition of the oil. Based on the combined seed yield data for both years, the salt tolerance threshold (the maximum allowable ECe without a yield decline) was 6.1 dS m-1 and the C50 (ECe value that would result in a 50% yield reduction) was 9 dS m-1. [As an approximation: ECe = 1.5 ECi]. Each unit increase in salinity above the threshold resulted in a 19% decrease in yield. Under nonsaline control conditions in the Brawley plots (ECi = 1.4 dS m-1), lesquerella was a strong calcium accumulator, and as external calcium increased in concert with salinity, leaf-Ca 2+ significantly...
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