EFFECT OF LIGHT, SODIUM-HYPOCHLORITE, SCA RIFICATION, AND STRATIFICATION ON SEED-GERMINATION OF LETTUCE (LACTUCA-SATIVA L), CV MAIOBA AND MORENINHA-DE-UBERLANDIA

The cultivars of lettuce ''Maioba'' and ''Moreninha-de-Uberlandia'' ar e vegetables of economic and nutritive potential with a high content o f A and C vitamins. Information about the factors that interfere on th e seed germination of these cultivars can be used to obtain a great nu mber of seedlings for a production in commercial scale. The seeds were submitted to 16 treatments with 5 replicates of 50 seeds each one. Th e seeds were cultivated between 21 and 24 degrees C, at 2088,38 mu W/c m(2) of average irradiance. The seeds of the two cultivars are positiv ely photoblastic, but ''Moreninha-de-Uberlandia'' is more dependent on light than ''Maioba.'' This sensibility and dependence of light disap peared in older seeds of the cv. ''Moreninha-de-Uberlandia''. The sodi um hypochlorite inhibited and retarded for 16 days the germination pro cess of seeds with 101 days of age, while for older seeds of this cult ivar sensibility to sodium hypochlorite disappeared. The stratificatio n accelerated the germination for this cultivar in relation to the oth er treatments. However, this treatment failed to accelerate the germin ation of seeds of the cv. ''Maioba''.