Avaliação da restrição do volume do recipiente de cultivo no crescimento e alocação de recursos em espécies arbóreas de Cerrado

Abstract

The decrease in the woody component of the Cerrado Biome vegetation is a major threat to remaining natural areas. Factors such as the low availability of seedlings of native species in nurseries and the conditions in which they are grown can end up affecting the outcome of these projects. THE Container volume is often considered one of the most influential variables on morphology. of the seedlings. Therefore, the restriction imposed by small containers on seedling cultivation may have consequences on the performance of the species even after planting in the definitive location. Therefore, the objective was to experimentally evaluate the effect of limiting the volume of the cultivation container of seedlings in growth in height and in the allocation of resources between roots and aerial parts of plants four native forest species. An experiment was conducted in a greenhouse, at Embrapa Gado de Corte in Campo Grande, MS among the months of April 2018 and January 2019. The fully randomized experiment consisting of three levels treatment: 110 cm3 volume tube (A1), 290 cm3 tube (A2) and 7000 cm3 tube (CT). The height of the seedlings was recorded weekly and at the end of 112 and 224 days the heights were also recorded. following architectural measurements: Root dry mass (MSR), shoot dry mass (MSPA), fraction of root mass (FMR) and plant dry mass (MSP). The growth of seedlings of the four species over time differed between treatments, with the CT container being the one with the highest averages at the end of 224 evaluation days. The volume of the culture vessel influenced the MSR and MSPA in 112 and 224 days for A. peregrina, M. urundeuva and J. cuspidifolia, but H. stigonocarpa was influenced only by cultivation time and not by treatments at each time. For FMR in H. stigonocarpa and J. cuspidifolia the smaller volume containers allocated more resources to the roots at 112 days, whereas A. peregrina at 224 days showed the same relationship. As expected, the container with the largest volume, citropote with 7000 cm³, was the one with the highest average plant heights at the end of the season. experiment. The volume available for root growth directly influenced the development of the root system and aerial parts of these plants. The adjusted models suggest that throughout growth, young plants tended to allocate less biomass to the roots in in relation to the aerial parts, with the exception of H. stigonocarpa in both times and J. cuspidifolia in the time 112 days.