Non-thermal plasma application improves Megathyrsus maximus germination, establishment, and productivity without compromising forage quality

PÉREZ PIZÁ, MARÍA CECILIA; LILIANA CLAUSEN; CEJAS, EZEQUIEL; FERREYRA, MATÍAS; CHAMORRO-GARCÉS, JUAN CAMILO; FINA, BRENDA; ZILLI, CARLA; VALLECORSA, PABLO; PREVOSTO, LEANDRO; BALESTRASSE, KARINA

Crop and Pasture Science

CSIRO PUBLISHING

Lugar: Clayton; Año: 2022 vol. 73

Megathyrsus maximus ?Gatton Panic? is a tropical grass highly valued both for its use as forage as well as for its biofuel potential. A major problem to be tackled in establishing pastures of this cultivar is related to the low viability and germination of seeds and the poor initial seedling establishment. We used non-thermal plasma (NTP) as a novel technology to treat seeds of this grass, intending to improve their quality (germination traits). We also followed the performance of seedlings grown from NTP-treated seeds under field conditions by assessing seedling establishment, biomass production and forage quality during the first regrowth period (critical period for pasture establishment). NTP treatments were performed through dielectric barrier discharges employing N2 as carrier gas. Non-treated seeds served as the control. Results here reported showed, on one hand, that the viability of NTP-treated seeds was, on average, 1.5-fold higher than the control, and on the other hand, that germination energy and germination percentage outperformed the control by 2.1-fold and 2.2-fold, respectively. Likewise, a field experiment showed that seedling establishment parameters (dynamics of cumulative emergence, emergence coefficient, and weighted average emergence rate) and pasture early productivity (represented by shoot dry matter) were enhanced by plasma treatment (PMN3), showing 1.4-2.6-fold higher values than the control, confirming the results observed in the laboratory assays. Although NTP increased markedly the shoot dry matter production of the pasture (which was related to a higher tiller population density and greater tiller weight), it did not affect the forage quality of the plants generated in the field. It can be concluded that NTP technology is suitable to improve seed germination of M. maximus ?Gatton Panic?, which in addition leads to improvements in seedling establishment and biomass production under field conditions, without compromising the quality of the forage.