Avaliação da brotação de tubérculos de Cyperus rotundus pelo teste de respiração

Abstract

The breath test is a indirect biochemical test that means to measure the amount of oxygen consumed, has been extensively used in measuring the respiration rate of seeds and soil respiration. The objective was to develop and validate a methodology to assess sprouting of purple nutsedge (Cyperus rotundus) tubers by breathing test. In order to develop the methodology, tests were carried out with the objective of homogenizing the sprouting. In these tests the tubers suffered a preconditioning with glucose, gibberelic acid or with distilled water. In addition to validate the methodology it was used the glyphosate in five rates that was sprayed in pots infested with C. rotundus at the full development (before flowering). The results obtained showed that there is no significant difference in the sum of the breathed amount considering the use of glucose or water in the preconditioning and a reduction in use of gibberellic acid. In the period of 48-96 hours the CO2 production was decreased with the increased glyphosate rate, as well as the percentage of sprouting. Therefore the proposal methodology can be used as a fast and simple technique to foresee the percentage of sprouting tubers.