Germination and Emergence of Digitaria insularis (L.) Fedde Susceptible and Resistant to Glyphosate

To Know the behavior shown in seed germination and emergence of Digitaria insularis (L.) Fedde enables develop strategies to reduce the seed bank in cultivated areas. The aim of this research was to evaluate the germination and emergence of weed biotypes of D. insularis susceptible and resistant to glyphosate in two substrates.

The experiment was divided into two stages (germination test in BOD and emergence in sand box). In both phases of the study, it was used a completely randomized experimental design, with two treatments (weed biotypes of D. insularis susceptible and resistant to glyphosate) and ten replications.

The work was done in the State University of Western Paraná, Brazil, Post-Graduation in Agronomy, between July 2018 and December 2018.

In the two tests the experimental units consisted of 25 seeds of D. insularis, evenly distributed. In the germination test was evaluated the first count and the index of germination speed. In the same way, for the emergency test was evaluated the first count and the index of emergence speed. It was also calculated the germination and the emergence percentage, total number of germinated seeds, total number of emerged plants.

Differences were observed in the first count, index of germination speed and germination percentage, seeds of D. insularis susceptible and resistant to glyphosate. During the first count, susceptible biotype showed higher germination, with 78% of compared to resistant. Similar behavior was observed for the index of germination speed and for the germination percentage, in which the susceptible biotype surpassed in 80.4% and 47%, respectively, the resistant biotype.

Conclusion: The selection of D. insularis biotypes resistant to glyphosate affects the germination and emergence, the species in relation to the original population of susceptible biotypes. For each 100 seeds of the biotype resistant to glyphosate 53 seeds of them germinate and 32.6 seeds can emerge.