ProLigno / ProLigno 2010 Numarul 2  
     
 
 
   
 

 

 

 

 

 

 

 

MODIFICARI INDUSE DE TRATAMENTUL FITOSANITAR ISPM-15 ASUPRA SUBSTANTELOR EXTRACTIVE DIN PINUL SILVESTRU SI EFECTUL ASUPRA COLORATIILOR CAUZATE DE FUNGI

Gerda LAMBERTZ
Dr.eng. - Johann Heinrich von Thuenen-Institute (vTI), Federal Research Institute for Rural Areas, Forestry and Fisheries, Institute of Wood Technology and Wood Biology (HTB)
Adresa: Leuschnerstrasse 91, 21031 Hamburg, Germany
E-mail: gerda.lambertz@vti.bund.de

Johannes WELLING
Dr.eng. - Johann Heinrich von Thuenen-Institute (vTI), Federal Research Institute for Rural Areas, Forestry and Fisheries, Institute of Wood Technology and Wood Biology (HTB)
Adresa: Leuschnerstrasse 91, 21031 Hamburg, Germany
E-mail: johannes.welling@vti.bund.de

Rezumat:
        In conformitate cu Standardul International de Masuri Fitosanitare (ISPM-15), tratamentul termic este una dintre cele mai importante metode pentru a evita raspandirea organismelor daunatoare din carantina, cum ar fi insectele si nematozii, atunci cand se utilizeaza ambalaje din lemn. Standardul defineste un tratament termic la temperatura de 56°C cu o durata de cel putin 30 de minute, fara nicio referire la continutul de umiditate din lemn si nici la prezenta ciupercilor dupa tratament. In aceste conditii, si anume cu un tratament termic pur, fara uscare artificiala, continutul de umiditate al lemnului nu scade. In consecinta, este o problema frecventa faptul ca, in special alburnul in stare verde prezinta o afinitate mare pentru mucegai si albastreala. Infestarea este mult mai mare in comparatie cu probele corespunzatoare de lemn netratat. Nu se stiu multe despre cauzele acestui fenomen.
        Studii recente au prezentat mai multe considerente esentiale pentru dezvoltarea mucegaiului pe alburnul de pin in stare verde dupa un tratament termic. S-a demonstrat ca, diferiti parametri ai materialului s-au modificat semnificativ in timpul tratamentului termic: continutul de componente lipidice, precum si continutul de zaharuri libere a crescut, in timp ce valoarea pH-ului din lemn a scazut. Cu toate acestea, nu a putut fi dovedita o migrare de zaharuri libere in stratul exterior si nici o stimulare de ciuperci termofile, sau o schimbare a distributiei de umiditate in sectiune transversala. Investigatii suplimentare au condus la gasirea unor agenti ecologici pentru inhibarea temporara a capacitatii germinative a fungilor pe suprafetele ambalajelor din lemn. Agentii alcalini reduc continutul de grasimi, probabil prin saponificare. Cu toate acestea, uscarea (fie naturala sau artificiala) este indispensabila pentru a evita un risc fungic pe termen lung. O combinatie de tratament alcalin temporar, imediat dupa taiere, urmata de o uscare la aer, pare a fi cea mai eficienta si economica metoda de a proteja conform ISPM 15 ambalajele din lemn tratat cu materiale impotriva ciupercilor care produc coloratii.


Cuvinte cheie: albastreala, acizi grasi liberi, zaharuri libere, mucegai, valoarea pH-ului, tratament fitosanitar, materiale de ambalare din lemn.

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Pagina creata de Costel AGACHE. Intretinere pagina Luminita Brenci. Ultima actualizare, 15 Iulie 2010