Three lots of cucumber (Cucumis sativus L.) seeds cv. Rubi were germinated in
blotter paper soaked with solutions of poliethylene glycol. The effect of water stress during seed
germination and development of cucumber seedlings was evaluating by using five osmotic potentials
zero; -0.2; -0.4; -0.6 and -0.8MPa. This research was conducted in the Seed Analysis Laboratory
of the Vegetable Production Department of the Escola Superior de Agricultura ?Luiz de
Queiroz?(ESALQ/USP) from March to May 1999. Percentage of germination, first count, abnormal
seedlings, seedling length and dry matter production of seedlings were avaluated. The results
showed that the gradual reduction of osmotic potential of substrate induced a reduction of
germination and mainly development of cucumber seedlings. Osmotic potentials equal and lower
than -0.4MPa were critical to seed germination and development of cucumber seedlings,
respectively