Effect of light regime, gibberellic acid and scarification method on the germinability of glyphosate resistant and susceptible perennial ryegrass

SUPICICHE, MARÍA LAURA; LONGÁS, MARÍA DE LAS MERCEDES; CHANTRE, GUILLERMO RUBÉN; SABBATINI, MARIO RICARDO

Rosario

Congreso; II Congreso Argentino de Malezas (ASACIM): Malezas 2018. Ciencia, producción y sociedad: hacia un manejo sustentable.; 2018

Asociación Argentina de Ciencia de las Malezas (ASACIM)

Lolium perenne is a problematic weed that has generated resistance to glyphosate herbicide, as result of weed management solely based on the use of chemical control. Knowledge of the biological behavior of resistant (R) and susceptible (S) biotypes is important to predict and manage herbicide resistance. Differences among Lolium S and R biotypes related to dormancy and how environment factors influence on this trait have not been clearly elucidated. The objective of this work was to determine the effects of light regime, different scarification methods and gibberellic acid addition on the germinability of both glyphosate-resistant and sensitive biotypes of ryegrass. Fresh seeds were dry stored for 60 days and then incubated at 15/25 ºC under the following treatments: intact (E), cut (C) and naked caryopses, exposed to light (L) or dark (D) regimes, with and without gibberellic acid (1000 ppm, AG3). Germination was measured on a daily basis during ten days and final germination percentage (FGP) was calculated for the viable fraction of the seed population. A similar FGP was observed for both biotypes in all treatments. Light and AG3 significantly improved germination, 96,4 (L) vs 93,5 (D) % and 96,8 (AG3) vs 93,5 % (without AG3) (p