Browsing by Author "Neves, N."
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- Decision support tools for optimising kiwifruit production and qualityPublication . Panagopoulos, Thomas; Rodrigues, S.; Neves, N.; Cruz, S.; Antunes, Maria DulceThe importance of kiwifruit (Actinidia deliciosa 'Hayward') production has increased greatly during the last decade in the Portuguese region of Beira Litoral. However, information on the nutritional status of this crop in this soil/climatic zone is scarce. The objective of this work was to use techniques such as geographic information systems (GIS) and geostatistics to generate information that can be used to optimise physical and financial aspects of kiwifruit production systems. A regional survey was conducted over three years (2002-2004) in 15 geo-referenced orchards of Beira Litoral. Soil analysis and fruit production and quality were determined. In order to understand the variation of kiwifruit quality and production factors, graphical interpretation of these properties was done using GIS, geostatistics and principle component analyses (PCA). Ordinary kriging was the geostatistical technique used for creation of prediction maps, which were then introduced into a GIS and their values reclassified. Maps of biophysical characteristics of the region were then related to the generated GIS/geostatistical maps using PCA. Areas with highest potential production and quality were located. Site specific management methods could improve productivity and quality. Those maps can help the producer to make decisions about harvesting time or localized correction of production factors and to choose the best place for vineyard installation in the region. There was a strong correlation between the map of yield and quality factors. An in-depth analysis of PCA showed which parameters were the most important as production factors for quality and yield; therefore this methodology was important for analysis of relations of different parameters in agricultural studies.
- Taste panel quality evaluation of 'Hayward' kiwifruit of different originsPublication . Franco, J.; Melo, F.; Guilherme, R.; Neves, N.; Curado, F.; Antunes, Maria DulceIn Portugal, the regions of Entre-Douro e Minho and Beira Litoral have exceptional conditions for the production of good quality kiwifruit. However, demand exceeds local supply resulting in importation of kiwifruit from Italy, Chile and New Zealand. Taste panels were run in December, May and June to study the preferences of Portuguese consumers for 'Hayward' kiwifruit. In December, a comparison was made between kiwifruit from Portugal and Italy, in May between kiwifruit from Portugal and Chile and in June between kiwifruit from Portugal, Chile and New Zealand. Attributes assessed by panellists were: appearance, texture, flavour, sweetness and acidity. The same samples were analyzed for: weight, equatorial and longitudinal diameter, firmness, soluble solids (as measured by refractometer) and titratable acidity. In May, panellists preferred Portuguese kiwifruit, but in December and June the preference was not so clear. In December, Portuguese kiwifruit were not at the eating ripe stage and in June they were at the end of their storage life (bad appearance but better flavour, sweetness and texture).
- The effect of calcium applications on kiwifruit quality preservation during storagePublication . Antunes, Maria Dulce; Neves, N.; Curado, F.; Rodrigues, S.; Franco, J.; Panagopoulos, ThomasIt is well known that calcium increases storage life of many fruits. This study investigated the effect of vine calcium application, as well as postharvest application on storage behaviour of 'Hayward' kiwifruit. Three applications of 0.03% CaCl2 or CaO were made in June, July and September. After harvest half of the fruit from sprayed vines were dipped in a solution of 2% CaCl2; the other fruit were untreated. All fruit were then stored at 0 degrees C and relative humidity of about 90-95%. Results for fruit of the size range 85-105 g are discussed. Kiwifruit dipped in 2% CaCl2 postharvest maintained higher firmness through storage than undipped fruit, but soluble solids content was only slightly lower after storage. This suggests that postharvest dipping of kiwifruit in 2% CaCl2 benefits storage life. The concentrations of 0.03% CaCl2 (Antistip) or 0.03% CaO (Chelal) used in vine applications seem to be too low and higher concentrations should be tried.
- The effect of pre- and postharvest calcium applications on 'Hayward' kiwifruit storage abilityPublication . Antunes, Maria Dulce; Panagopoulos, Thomas; Neves, N.; Curado, F.; Rodrigues, S.The benefits of calcium applications pre and postharvest on fruit storage ability have been mentioned in the bibliography. It was objective of this work to study the effect of calcium preharvest application in two different forms and calcium chloride application postharvest on 'Hayward' kiwifruit storage ability. Kiwifruit vines were sprayed with 0.03% CaCl2 or 0.03% CaO at one, three and four months before harvest. The control did not have any treatment. After harvest, half fruits were dipped for 2 min in a solution of 1% CaCl2, left to dry and stored at 0 degrees C. The other half was stored at the same temperature without any treatment. The commercial yield was not affected by treatments. During storage, fruits dipped in 1% CaCl2 softened slower and than fruits not treated. Weight loss was higher in fruits treated with CaO preharvest. SSC showed a significant decrease in fruits sprayed with CaO from 4 to 6 months storage. This work suggests that immersion of kiwifruit in 1% CaCl2 postharvest benefits storage life capacity; preharvest spraying with CaCl2 seems to be better than with CaO. However, we have to try higher calcium concentrations in order to get better results in storage ability but, without causing toxicity on the vines.