Leaf : fruit ratio and irrigation supply affect seasonal changes in minerals, organic acids and sugars of mango fruit

To determine the effects of assimilate and water supply on the determination of mango fruit quality, the seasonal variations of minerals, acids and sugar concentrations were investigated over two successive years. To manipulate the assimilate supply, selected branches were girdled to provide ratios of 10, 25, 50 and 100 leaves per fruit. Irrigation was managed to provide two types of water supply treatments. Fruit growth rate was greater when increasing the leaf:fruit ratio. Structural dry matter content and total dry matter content of flesh were higher in fruit with higher leaf:fruit ratios. Treatments had no effect on the structural to total dry matter ratio of flesh. Potassium and magnesium to structural dry weight ratios were not affected by treatments, whereas the calcium to structural dry weight ratio was higher in the flesh of fruit grown under low leaf:fruit ratios. Low assimilate supply increased the ratios of malle and citric acid to structural dry weight. This treatment had little effect on acid concentrations. Glucose and fructose to structural dry weight ratios were higher when assimilate supply was lower. Low leaf:fruit ratios increased fructose concentration but not glucose concentration. Irrigation treatment strongly affected fructose concentration. Sucrose concentration, based either on structural dry matter or on fresh matter, was significantly increased by higher leaf-to-fruit ratios. When the fruit was close to maturity, levels of sucrose storage and starch breakdown were positively correlated with assimilate supply. Levels of starch breakdown were correlated with irrigation supply. The effects of these treatments on sugar concentrations may change fruit taste. (Résumé d'auteur

An overview of preharvest factors influencing mango fruit growth, quality and postharvest behaviour

International audienceMango, a tropical fruit of great economic importance, is generally harvested green and then commercialised after a period of storage. Unfortunately, the final quality of mango batches is highly heterogeneous, in fruit size as well as in gustatory quality and postharvest behaviour. A large amount of knowledge has been gathered on the effects of the maturity stage at harvest and postharvest conditions on the final quality of mango. Considerably less attention has been paid to the influence of environmental factors on mango growth, quality traits, and postharvest behaviour. In this paper, we provide a review of studies on mango showing how environmental factors influence the accumulation of water, structural and non-structural dry matter in the fruit during its development. These changes are discussed with respect to the evolution of quality attributes on the tree and after harvest. The preharvest factors presented here are light, temperature, carbon and water availabilities, which can be controlled by various cultural practices such as tree pruning, fruit thinning and irrigation management. We also discuss recent advances in modelling mango function on the tree according to environmental conditions that, combined with experimental studies, can improve our understanding of how these preharvest conditions affect mango growth and quality. (Résumé d'auteur)Manga, um fruto tropical de grande importância, é geralmente colhido verde e comercializado após um período de armazenamento. Infelizmente, a qualidade final da manga na prateleira é altamente heterogênea, em termos de tamanho do fruto, qualidade do paladar e comportamento pós-colheita. Tem-se obtido uma quantidade expressiva de informações sobre os efeitos do estádio de maturação e condições pós-colheita sobre a qualidade final da manga. Contudo, tem-se dado atenção consideravelmente menor à influência dos fatores ambientes sobre o crescimento da manga, características de qualidade e comportamento pós-colheita. Neste artigo, faz-se uma revisão dos estudos sobre manga, evidenciando-se como fatores ambientes afetam o acúmulo de água e de matéria seca estrutural e não-estrutural nos frutos durante o seu desenvolvimento. Discutem-se essas alterações com relação à evolução de atributos de qualidade dos frutos ainda nas plantas e após a colheita. Os fatores de pré-colheita abordados são luz, temperatura, disponibilidades de água e de carbono, raleio de frutos e manejo da irrigação. Discutem-se também recentes avanços sobre modelagem associada à função do fruto na planta, conforme as condições ambientes que, combinados com estudos experimentais, pode melhorar a nossa compreensão sobre como as condições de pré-colheita afetam o crescimento e a qualidade da manga