The aim of the work was to evaluate the effect associated with water stress and aluminum sublethal doses on seed germination of pigeonpea, IAPAR 43-Aratã and IAC Fava Larga cultivars. The experiment was carried out at Faculdade de Ciências Agrárias e Veterinárias-UNESP, in Jaboticabal, São Paulo State, from March to May 2002. The seeds germinated in germination boxes lined with blotters moistened with solutions of polyethyleneglycol, PEG 6000 (0,0; -0,6; -0,9, -1,2 e -1,5 MPa) and aluminum sulphate (0,0; 2,5; 5,0; 7,5; e 10,0 mmol.dm-3). The experimental design was a complete randomized in factorial arrangement 2 x 5 x 5 (2 cultivars; 5 water stresses; 5 aluminum doses) and four replications of 50 seeds. The statistical analysis was complemented with the clustering analysis and principal component analysis. Seed germination was evaluated, four and ten days after sowing. The experiment was conducted in germination chamber at 25 °C ± 1 °C. On the tenth day, the seedlings were separated in plumule and radicle for dry mass determination. The water stress appeared to be the critical limiting factor for germination and seedling establishment. The joint effects of water stress and aluminum were significantly greater at moderate water stress, the effects of aluminum being more pronounced only when severe water stress was absent. The germination of the IAPAR 43-Aratã cultivar and the roots growth of the IAC Fava Larga cultivar were reduced, respectively, by water stress and aluminum.
osmotic stress; aluminum toxicity; forage; legume
