Cinética da secagem de amostras de pera com geometrias distintas em secador solar (Pyrus L. ) / Drying kinetics of pear samples with different geometries in solar dryer

O objetivo do estudo foi realizar a desidratação de amostras de pera através da secagem solar e obter as respectivas curvas de secagem. As amostras foram submetidas à desidratação em dois tipos de geometrias, circulares com 1cm de espessura e em cubos com 1cm de comprimento. Os dados experimentais das curvas de secagem para as duas condições foram ajustados ao modelo matemático de secagem baseado na Segunda Lei de Fick. Os resultados mostram que a umidade do fruto é de aproximadamente 85%. As amostras apresentaram peso constante a partir de 18 horas de experimento para a geometria plana e a partir de 30 horas para a geometria cilíndrica. O coeficiente difusivo, obtido através da aplicação da Segunda Lei de Fick, para geometria plana foi de 6,4 x 10(-4)m2/s e para a geometria cilíndrica de 3,35 x 10(-4) m2/s.

Influence of rootstocks on growth, yield, fruit quality and leaf mineral element contents of pear cv. 'Santa Maria' in semi-arid conditions

BACKGROUND: Rootstocks play an essential role to determining orchard performance of fruit trees. Pyrus communisand Cydonia oblonga are widely used rootstocks for European pear cultivars. The lack of rootstocks adapted to different soil conditions and different grafted cultivars is widely acknowledged in pear culture. Cydonia rootstocks (clonal) and Pyrus rootstocks (seedling or clonal) have their advantages and disadvantages. In each case, site-specific environmental characteristics, specific cultivar response and production objectives must be considered before choosing the best rootstock. In this study, the influence of three Quince (BA 29, Quince A = MA, Quince C = MC) and a local European pear seedling rootstocks on the scion yield, some fruit quality characteristics and leaf macro (N, P, K, Ca and Mg) and micro element (Fe, Zn, Cu, Mn and B) content of 'Santa Maria' pear (Pyrus communis L.) were investigated. RESULTS: Trees on seedling rootstock had the highest annual yield, highest cumulative yield (kg tree(-1)), largest trunk cross-sectional area (TCSA), lowest yield efficiency and lowest cumulative yield (ton ha(-1)) in the 10th year after planting. The rootstocks had no significant effect on average fruit weight and fruit volume. Significantly higher fruit firmness was obtained on BA 29 and Quince A. The effect of rootstocks on the mineral element accumulation (N, K, Ca, Mg, Fe, Zn, Cu, Mn and B) was significant. Leaf analysis showed that rootstocks used had different mineral uptake efficiencies throughout the early season. CONCLUSION: The results showed that the rootstocks strongly affected fruit yield, fruit quality and leaf mineral element uptake of 'Santa Maria' pear cultivar. Pear seedling and BA 29 rootstock found to be more prominent in terms of several characteristics for 'Santa Maria' pear cultivar that is grown in highly calcareous soil in semi-arid climate conditions. We determined the highest N, P (although insignificant), K, Ca, Mg, Fe and Cu mineral element concentrations on the pear seedling and BA 29 rootstocks. According to the results, we recommend the seedling rootstock for normal density plantings (400 trees ha(-1)) and BA 29 rootstock for high-density plantings (800 trees ha(-1)) for 'Santa Maria' pear cultivar in semi-arid conditions.