Efeito de altas concentrações de CO₂ no desenvolvimento do feijoeiro do tipo preto (phaseolus vulgaris l.)

Abstract

The rising of atmospheric carbon dioxide (CO₂) levels due to anthropogenic activities, have been altering global climate systems and affecting ecological and agricultural stability. Among the various consequences, changes in plant physiology and growth patterns can have impacts on essential ecological services and food security. This study aimed to investigate the effects of elevated CO₂ levels on the vegetative growth of Phaseolus vulgaris (black bean), a crop of considerable agricultural and nutritional relevance. To this end, two controlled-environment experiments were conducted in a climate chamber, where light intensity, temperature, humidity, and CO₂ concentrations were adjusted. Bean plants were exposed to high CO₂ concentrations (approximately 1000 ppm on average) over a 22 day period, which corresponded to their senescence time observed under these conditions. Additionally, a comparative experiment was carried out in a greenhouse under ambient CO₂ levels. Growth indicators, including height and dry biomass, were measured to assess growth responses to CO₂ enrichment. Although CO₂ is an essential component of photosynthesis and, consequently, of plant metabolism, the data demonstrated that excessive increases — above 1000 ppm — can trigger adverse physiological responses in black bean plants, such as premature senescence and restricted growth. The metabolism of black bean plants doesn't seem to be neither adapted nor prepared to withstand high CO₂ concentrations.