Studio della qualità nella filiera produttiva di ortive di IV gamma allevate con float system. Caratterizzazione delle molecole antiossidanti e valorizzazione di mercato
Author(s)
Salerno, Anna
Date Issued
November 19, 2008
Type
Doctoral Thesis
Abstract
The object of this thesis was the evaluation of yield and quality of radish grown in a floating system on the bases of plant density and ion strength of nutrient solution.
Experiments were carried out at the experimental farm of the University of Tuscia (Central Italy) in an unheated greenhouse on a floating system during the spring –summer period of the 2004 and 2005 years.
The experiments of 2004 was focused on the effect of two cultivars(Girox and Suprella), and two plant densities(720 and 1320 plant/m2) on yield, mineral composition and quality of radish.
Subsequent experimental phase, during spring-summer 2005, has concerned the effect of nutrient solution concentration on both yield response and quality of radish grown in a floating system using a plant density of 720 plants/m2. A factorial combination of three nutrient solution concentrations and two cultivars, Girox and Suprella, were compared in a randomized complete block design with three replicates. Nutrient solutions were: full strength solution, ¾ and ½ of full strength namely 100%, 75% and 50%.
At harvesting were measured: yield, size of hypocotyls and distribution of size classes. The hypocotyls macro and microelements content, the radicals scavenging activity as well as the concentration of the major bioactive molecules such as total polyphenols, anthocyanins, and glucosinolates were determined by inductively coupled plasma spectrometry and spectrometric and chromatographic (HPLC) analysis. Moreover, their chemical characterization by means of nuclear magnetic resonance was performed too in order to identify any correlation between specific NMR emission spectrum signal and considered agronomic and environmental variables, such as nutrient solution concentration, cultivar and growing season.
In the light of overall results collected during two experimental phases, the following conclusions can be drawn: - the first features is the easiness of the float system as well as the recyclability of the most materials used, such as panels of polystyrene and tanks filled with nutrient solution. This in part allows a capital consumption allowance for initial installation charges; - float system is suitable to cultivate ready to eat radish and a plant density of 720/plant m2 is the better to obtain a good yield and quality product; - the results suggested that in the floating system cultivation of radish, the use of a reduced nutrient content solution is feasible and also indispensable in order to obtain a good quality and quantity yield. A reduction of nutrient solution concentration at 75% and 50% should be preferred in spring and summer seasons respectively rather than 100% ones; - the obtained product has also showed to possess satisfactory qualitative characteristics and by fulfilling the consumer’s requirement for both mineral and bioactive compounds such as low nitrate and good level of glucosinolates and antocianins;- NMR data showed a variation of sugar substances on the bases of cultivar, season and nutrient solution concentration factors; - Finally, the system offers the further advantage that is to carry out many consecutive growing cycles thanks to their shortness.
Additional information
Dottorato di ricerca in Ortoflorofrutticoltura
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