The objective of this work was to evaluate the effect of matrix and osmotic conditioning on the physiological quality of seeds of herbaceous cotton. Seeds of the chemically delinted cotton cultivar Panton were used at the ratios of 100 g of seeds per 1000 g of solid matrix (Algalita). The treatments consisted of five levels of water used for wetting the matrix (0.10, 0.25, 0.50, 0.75 and 1.00 mL) during six conditioning periods (0, 1, 4, 8, 16 and 32 days). Two assays were carried out for the osmotic conditioning: seeds treated with osmotic solutions of polyethylene glycol (PEG) 6000 (-0,25 MPa) and potassium nitrate (0,3 M or -0.72 MPa) at seven times of osmotic conditioning (0, 12, 24, 36, 48, 72 and 96 h) at 20 ° C. The variables analyzed were percentage of germination and length of seedlings. The experiment was arranged in a complete randomized design with four replications. There was increase in the vigor of seeds conditioned with different levels of moisture in the solid matrix compared with the control. The ability to reinvigorate of the treatment with 0.50 mL water was confirmed with the increased time of seed exposure to the solid matrix; the osmotic conditioning with PEG 6000 increased seed vigor, but did not promote germination, and the osmotic conditioning with potassium nitrate reduced germination, but increased seed vigor in the first 24 hours of hydration - of seeds disinfested with sodium hypochlorite - and up to 48 hours for seeds treated with N-[(trichloromethyl) tio]-4-cyclohexene-1 ,2-dicarboximide (concentration of 750 g / kg).
Seed quality; solid matrix; delinted seeds; osmotic solution; Gossypium hirsutum L.
