Influência do potencial osmótico e da salinidade na germinação de azevém

Abstract

The spontaneous plant popularly known as ryegrass has caused problems in winter crops, because it has entered into competition with the crops of interest, having an increasingly difficult management due to resistance to chemicals, and this species settles well in the crops of the southern region of Brazil, it’s becomes important to studies on the ecology of germination of this plant, that has brought problems to the crops of region, so that it is possible to adopt a management of this species before its establishment in the area. The experiments sought to evaluate the influence of the osmotic potentials and salinity in germination of ryegrass seeds. The bioassays were conducted in growth chambers with temperature control and photoperiod model BF2 CGFP 295, brand Biofoco. Temperatures were alternated from 20 °C to 35 °C and photoperiod cycles were alternated from day/night from 12/12 hours. For germination tests at different osmotic potentials, the equivalent concentrations of (ψs) of 0.00, -0.05, -0.10, -0.20, -0.40, -0.80 and -1.20 MPa of PEG at 35 °C were used, and for salinity tests concentrations of 0, 10, 20, 40, 80, 120 and 200 mM of NaCl with distilled water were used. The results showed that there was a suppression of the germination of ryegrass seeds as the osmotic potential of the solutions increased. The percentages of normal and abnormal seedlings were also influenced by the concentration of NaCL in the gradient. Salinity also showed significant effects on seedling germination and on the formation of normal ryegrass seedlings.