RESUMO
ABSTRACT Studies related with the storage of peach fruits have received great relevance in Egypt. In this study, the effect of pre-harvest sprays of calcium chloride and chitosan, separately and in combination, on quality attributes and storability of peach fruits stored at 0±1 °C was studied. 'Early Swelling' peach trees were sprayed twice with 1% or 2% calcium chloride. The first spraying was at pea stage, while the second one was performed at 10 days before harvesting. Chitosan sprays were performed at 0.5 or 1%, alone or in combination with 1 and 2% calcium chloride, at 10 days before harvesting. Untreated trees served as control. Fruits were harvested at maturity stage, then packaged and stored at 0±1 °C and 85-90% of relative humidity. Fruit physical and chemical properties were evaluated at 7-day intervals. Results showed that pre-harvest application with 2% CaCl2+1% chitosan was most effective in minimizing weight loss (%) and decay (%), as well as in maintaining maximum firmness and lengthening shelf life. Fruit color was not affected by any of the treatments, while untreated fruits and calcium chloride treatment alone, at both applied concentrations, maintained higher total soluble solids (TSS, %), total phenolic content, and lower titratable acidity percentage.
RESUMO Estudos relacionados ao armazenamento de pêssego tem sido considerado de grande relevância no Egito. Neste estudo, o efeito da pulverização pré-colheita com cloereto de calico e quitosano, isoladamente ou em conjunto, na qualidade e na capacidade de armazenamento de frutos de pessegueiro armazenados a 0±1 °C foi avaliada. Frutos da variedade 'Early Swelling' foram tratados com 1,0 ou 2,0% de cloreto de cálcio. O primeiro tratamento foi aplicado num estado precoce de formação do fruto enquanto o segundo foi aplicado 10 dias antes da colheita. Quitosano foi aplicado nas concentrações de 0,5 ou 1,0%, isoladamente ou em combinação com 1,0% ou 2,0% de cloreto de cálcio também 10 dias antes da colheita. Árvores não tratadas serviram como controle. Os frutos foram colhidos quando maduros, empacotados e mantidos a 0±1 °C e sob condições de humidade relativa de 85-90%. Propriedades físicas e químicas dos frutos foram avaliadas em intervalos de 7 dias. Os resultados mostraram que a aplicação de 2% CaCl2 + 1% quitosano foi a mais eficaz em minimizar a perda de peso (%) e a senescência (%), bem como na manutenção da rigidez e aumento do período de vida em prateleira. A cor dos frutos não foi afectada por nenhum dos tratamentos enquanto frutos não tratados e cloreto de cálcio isoladamente, em ambas as concentrações, mantiveram um elevado teor de sólidos solúveis totais (TSS, %), elevado teor de fenóis e reduzida percentagem de acidez de titulação.
RESUMO
Greenhouse and field studies were performed to examine the growth responses and possible phytoremediation capacity towards heavy metals of several Brassicaceae (Brassica alba, Brassica carinata, Brassica napus and Brassica nigra) and Poaceae (durum wheat and barley). Soils used featured total concentrations of Cr, Cu, Pb and Zn largely exceeding the maximum levels permitted by the Italian laws. Different organic amendments were tested such as a compost and the plant growth-promoting rhizobacterium Bacillus licheniformis. In the greenhouse experiment, plant length, leaf area index and shoots dry matter were evaluated periodically for the Brassicaceae examined. Whereas plant length, grains production, weight of 1,000 seeds, ear fertility and tiller density were determined under field conditions at the end of the crop cycle for wheat and barley. In general, the species tested appeared to be tolerant to high heavy metal concentrations in soil, and slightly significant differences were found for all parameters considered. A marked growth increase was shown to occur for Brassicaceae cultivated on compost- and bacillus-amended contaminated soils, with respect to non-amended contaminated soils. With some exception, higher growth parameters were measured for wheat and barley plants cropped from contaminated soils in comparison to non-contaminated soils. Further, bacillus amendment enhanced the length of wheat and barley plants in both non-contaminated and contaminated soils, while different effects were observed for the other parameters evaluated.