Sensitividade do capim-jaraguá (Hyparrhenia rufa) à radiação gama

The sensitivity of seeds and axillary buds of Jaragua grass (Hyparrhenia rufa) to gamma radiation was evaluated in greenhouse. In the seed trial, doses from zero to 1100 Gy were applied to 500 fertile seeds per dose. The LD50 at 34 days was 600 Gy. For axillary buds, five month old plants with an average of four tillers each were irradiated with doses of zero to 90 Gy. Tiller number before irradiation (initial tillers) and 93 days after treatment (final tillers) were recorded. Doses of 80 and 90 Gy were responsible for the reduction of 31 and 42% in the number of tillers, respectively.