Iskanje po katalogu digitalne knjižnice

Ključne besede: hruška, rast, rodnost, giberelini, proheksadion-Ca
Objavljeno v DKUM: 10.07.2015; Ogledov: 1952; Prenosov: 49
Povezava na celotno besedilo

Opis: Med marcem in septembrom 2012 smo na FKBV izvajali poskus, s katerim smo želeli preučiti vpliv različnih pogojev skladiščenja na spreminjanje nekaterih parametrov kakovosti jabolčnega soka sorte 'Mutsu'. Spremljali smo spremembe barve soka (parameter L, a* in b*), topne suhe snovi (° Brix) in pH-vrednosti. Sok smo skladiščili na tri načine: sobna temperatura + svetloba, sobna temperatura + tema, hlajeno + tema, ki so hkrati predstavljali obravnavanja. Kot skladiščni pogoj, pri katerem je prišlo do najmanjših sprememb parametrov kakovosti jabolčnega soka, se je pokazalo skladiščenje pri sobni temperaturi in v temi (20–25 °C). Sobna temperatura je v času skladiščenja vplivala na preprečevanje spremembe barve jabolčnega soka, medtem ko vpliv svetlobe in nizke temperature na spreminjanje spremljanih parametrov kakovosti ni bil izrazit.
Ključne besede: jabolčni sok, skladiščenje, kakovost, temperatura, svetloba
Objavljeno v DKUM: 01.12.2014; Ogledov: 1910; Prenosov: 244
Celotno besedilo (1,51 MB)

Opis: V letu 2010 smo na posestvu Fakultete za kmetijstvo in biosistemske vede UM ugotavljali vpliv različnih načinov izrezovanja rodnih nosilcev na kakovost in količino pridelka pri jablani sorte 'Pinova'. V poskusu smo zastavili pet različnih obravnavanj, v katerih smo izrezovali rodne nosilce na čep ali prstan in njune različne kombinacije v zgornjem ali spodnjem delu krošnje. Drevesa smo obrezali v času zimskega mirovanja. Na podlagi rezultatov poskusa smo ugotovili, da različni načini rezi niso vplivali na vegetativno rast dreves. Statistično značilna razlika med obravnavanji je bila zaznana pri količini pridelka, povprečni masi posameznega ploda, deležu krovne barve in številu novih poganjkov. Največja količina pridelka je bila v obravnavanju, kjer smo izvedli rez na prstan (13,94 kg/drevo). Potrdili smo, da izrezovanje rodnih vej na čep ali prstan povzroči rast novih poganjkov, ki umirjeno izraščajo iz mesta izrezovanja. Največ novih poganjkov je bilo v obravnavanju, kjer smo rodne nosilce izrezovali na čep (3,4 novih pog./drevo), najmanj pa v obravnavanju, v katerem smo uporabili rez na prstan (1,75 novih pog./drevo).
Ključne besede: jablana, tip rezi, količina pridelka, kakovost pridelka
Objavljeno v DKUM: 29.07.2014; Ogledov: 2318; Prenosov: 219
Celotno besedilo (701,61 KB)

Opis: Colour and taste are important attributes of apple fruit quality that is generated during the fruit-growing period. Despite a plethora of studies dealing with this topic, the detailed information on how quality is generated is, however, still lacking. This is because traditionally, the obtained agro-morphological and biochemical data are analysed with empirical models using mean values of large samples, without taking the effects of biological variation into account, thus completely masking the spatio-temporal physiological mechanisms. To really understand quality, its generation during fruit growth needs to be monitored and modelled. When knowledge exists on the type and kinetics of the processes involved, the variation in properties can be described and taken into account by using so-called fundamental models, built on theoretical considerations. To understand the behaviour and the variation of colour and taste compounds, within or between individual fruits, and to assess their importance throughout the food supply chain, it is therefore important to understand the dynamics of these compounds during growth. The study consisted of (1) a preliminary experiment, aiming to determine the suitability of the semi-destructive biopsy sampling technique for in-vivo monitoring of certain metabolites during apple fruit development on a tree, (2) an experiment on spatial distribution, and (3) an experiment on temporal distribution of metabolites and colour in developing individual apple fruit. The experiment on spatial distribution was conducted to determine the effect of location on the accumulation of the individual quality components within apple fruit, and the parallel temporal experiment was conducted to monitor the dynamics and mechanisms of these components in apple fruit during on the tree development. Diameter and standard maturity indices of fruit flesh firmness, soluble solids content, starch degradation index, titratable acidity, and Streif maturity index were also determined, to obtain relations between individual quality components. Colour descriptors (L*, a* b*), individual sugars (fructose, sucrose, glucose), sorbitol, and individual organic acids (malic, citric, shikimic, fumaric) were monitored from 40 and 54 days before to 16 and 32 days after the optimum maturity for long term storage on individual apples of cv. ‘Gala’ and cv. ‘Pinova’. Data were analysed with classic empirical statistics as well as with non-linear indexed regression, based on process oriented models, which included biological variation between apples of the same batch. Frequently probelation and quantile regression were applied. The results of the preliminary experiment confirmed that the novel biopsy sampling technique is suitable for in-vivo monitoring of the spatio-temporal distribution of colour and individual taste components during on-tree apple fruit development. In the results from the experiment on spatial distribution, a sinusoidal distribution over locations at 70° above the fruit equator was observed for all the monitored quality components. Descriptor a* was highest at the blush, and b* and L* at the shaded side of the fruit. Citric acid preferentially accumulated at the shaded side of the fruit, whereas fructose in cv. ‘Gala’ tended to accumulate at the blush. Other metabolites were more or less equally distributed within fruit. The results of longitudinal monitoring reveal a sigmoidal increase of a*, an exponential increase of diameter and sugars, and an exponential decrease of organic acids over time. In both cultivars, large variations were observed between individual fruit for all the monitored quality components. When analysed with non-linear indexed regression, based on process-oriented models, and after the probelation combined with quantile regression, the explained parts of the majority of the monitored quality components were well above 90 %. The mechanism of colour development was the same for both cultivars. The biological shift factor for all metabolites and colour had roughly the same value within cultiv
Ključne besede: apple fruit, colour, models, organic acids, spatio-temporal monitoring, sugars
Objavljeno v DKUM: 19.12.2013; Ogledov: 3040; Prenosov: 303
Celotno besedilo (3,87 MB)

Opis: Leta 2011 smo v Sadjarskem centru Maribor izvedli poskus redčenja cvetov in plodičev jablane. Za primerjavo smo vzeli standardno kemično redčenje in različne kombinacije mehanskega in kemičnega redčenja. Poskus je bil izveden na sorti 'Pinova', cepljeni na podlago M9. Nasad, v katerem smo opravili poskus, ima namakalni in oroševalni sistem ter protitočno mrežo. Namen poskusa je bil primerjati učinkovitost mehanskega redčenja s strojem Tree Darwin in standardnega kemičnega redčenja ter uspešnost njune kombinacije v praksi. Zaradi zmanjšanja vpliva okolja in naklona terena so bila poskusna drevesa izbrana v šestih ponovitvah in v osmih obravnavanjih: 1. kontrola – neredčena drevesa, 2. ročno redčenje, 3. mehansko redčenje - Tree Darwin s 6 km/h in 250 obrati/min, 4. mehansko redčenje - Tree Darwin s 8 km/h in 350 obrati/min, 5. standardno kemično redčenje – Amid Thin v koncentraciji 1,2 kg/ha pri debelini plodičev 5 mm in nato še MaxCel v koncentraciji 4 l/ha pri debelini plodičev 14-16 mm, 6. BA (MaxCel) 4 l/ha, v 7. obravnavanje je bilo združeno tretje in šesto obravnavanje, v 8. obravnavanje je bilo združeno četrto in šesto obravnavanje. Glede na število plodov, maso in kakovost pridelka smo želene rezultate dosegli pri kombinaciji uporabe stroja Tree Darwin s 350 obrati/min pri 8 km/h in dodatku sredstva za redčenje MaxCel (11 kg/drevo, 180 g, 84 % plodov 1. kak. razreda). Izključno mehansko redčenje je zmanjšalo število plodov pri kontroli za 61% (obr. 3) oz. 35 % (obr. 4), vendar je delež plodov prvega kakovostnega razreda v teh primerih dosegel le 35 % oz. 69 %.
Ključne besede: jablana, 'Pinova', mehansko redčenje, kemično redčenje, Tree Darwin
Objavljeno v DKUM: 14.10.2013; Ogledov: 2732; Prenosov: 221
Celotno besedilo (372,23 KB)