Photosynthesis, nitrogen and sugar remobilization during the grain filling period were examined in two maize (Zea mays L.) hybrids (Pioneer 3072 and IAC 701 x B) submitted to water stress. The plants were grown under natural conditions in 12 boxes (4 m x 0,5 m x 0.6 m each) containing soil. Water stress was imposed by with holding irrigation during the 5.th and 15.th days after anthesis. Both hybrids in control treatment (without water stress) showed no differences in relation to the avaliated parameters. Under water stress the sugar and N remobilization from vegetative organs to the grains, were more intense than of the control plants. The sugar and N remobilization were larger in IAC 701 x B. The photosynthesis rates were reduced in both hybrids under water stress, but the reduction was larger in IAC 701 x B.
maize; Zea mays L.; water stress; CO2 exchange; growth; sugar; nitrogen