The study of seed germination physiology, especially of weeds, has been intensified due to the importance of knowledge on this subject to improve and create new techniques for weed management. Experiments were conducted in two phases to study the effects of different methods of overcoming the dormancy of Murdannia nudiflora (L.) Brenans seeds and light quality. In the first stage, the treatments consisted of seven methods of overcoming dormancy: mechanical scarification with sandpaper for 60 seconds; chemical scarification with sulfuric acid for 30, 60 and 300 seconds, sodium hydroxide 20% for 5, 15 and 25 minutes, sodium hypochlorite 2.5% for 24 hours, potassium nitrate (20 mM) for 24 and 48 hours, gibberellic acid (1 mM) for 24 hours and witness. A randomized complete statistical design was used with four repetitions. The germinated seeds were counted daily, and at the end of 30 days, the IVG was determined. In the second step, the quality of the light treatments consisted of 5 light filters (blue, green, red, transparent, and total absence of light). A higher percentage of seed germination was obtained using mechanical scarification (sanding) (84%), followed by chemical scarification with sulfuric acid for 1 minute (74%), sodium hypochlorite for 24 hours (46%) and sodium hydroxide for 25 minutes (26%). Quanto a porcentagem de germinação de sementes em função da qualidade de luz verificou-se as se Regarding the percentage of seed germination in function of the light quality of light,d the following germination percentages were observed: blue - with maximum reflectivity at 450 nm (58%), green - 500 nm (64%), red - 700 nm (75%), absence of light (0%) and transparently - without absorptivity in the region of 380 nm to 760 nm (87%). Seeds of M. nudiflora can be considered positive photoblastics.
photoblastism; mechanical scarification; phytochrome
