salinity stress and fibre-producing plants in egypt.

Experimental studies had been conducted on 3 fibre producing plants in Egypt, namely: Hibiscus cannabinus, Linum usitatissimum (cultivated plants) and Juncus acutus (wild plant) to study their tolerance to salinity in sandy soil. The changes in growth, fibre yield, contents of Na, K, P and N were studied under different concentrations of NaCl solution. The results indicate that Juncus is not a true halophyte, its growth was severely inhabited by NaCl concentration (up to 600 mM). Hibiscus and Linum are sensitive to high soil salinity. Moreover Linum showed high sensitivity to salinity than Hibiscus; at NaCl concentrations more than 100 mM Linum could not grow to maturity while Hibiscus grew but its yield was extremely low. The yield of Hibiscus was less affected by high salinity levels than that of linum. K/Na ratio was higher in Hibiscus than in Linum.  Salinity led to accumulation of P in the different organs of Linum and Hibiscus, but had relatively small effects on P concentrations of Juncus. The effect of salinity on N concentrations of the three species was small compared with the effect on the concentrations of P.