Dry matter yield, proline, total free amino acids and protein nitrogen contents in four varieties of linseed (Linum usitatissimum L.) were examined at five levels of zinc in water culture. Varietal differences in susceptibility to zinc deficiency and toxicity were noted. There was marked accumulation of proline under zinc deficiency. The more susceptible variety Heera, accumulated more proline. Under zinc deficiency, an increase in total free amino acids and decrease in protein nitrogen content were also observed.
