Effect of light and immersion in water on germination of globe amaranth seeds produced in the State of São Paulo, Brazil.


Two experiments were carried out with seeds of globe amaranth (Gomphrena globosa L.) cultivated at Jaboticabal, SP, Brazil. In the first experiment, at 20-30oC, the effect of 16 hours light or continuous darkness was compared for seeds of the varieties with white and purple inflorescences, just after their harvest. For both varieties, a higher germination percentage was verified under light. Without pretreatments for germination and under light, the average germination percentage ranged from 64.5 to 81.0%. The second experiment tested seeds of the variety with white inflorescences, stored for six months in a dry chamber. Germination at alternate temperatures of 20-30oC was slower in continuous darkness than in photoperiod of 16 hours; the previous immersion of the seeds in water for 24 hours was harmful to the germination percentage and to the germination speed.