DIGITALNA ARHIVA ŠUMARSKOG LISTA
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ŠUMARSKI LIST 1-2/1957 str. 31     <-- 31 -->        PDF

je da sav zaraženi materijal bude spaljen prije no što počne oslobađanje
spora iz piknida, to jest prije no što se oni otvore. Nove kulture treba
redovito pregledavati pogotovo od sadnje pa do kraja juna i u slučaju
pojave zaraze postupiti na isti način kao u rasadniku, da se bolest ne bi
raširila u kulturi.


U rasadnicima kao i u novim kulturama spaliti sve slabe i kržljave
biljke, koje bi mogle postati zaražene.


2. Preventivno prskanje bordoškom juhom (1—3°/o), u vrijeme
listanja (l°/o) i kasnije poslije svake jače kiše a najmanje svakog mjeseca.
Preporuča se da se premazuju stabla u kulturama s 2—3% bordoškom
juhom bar dva puta u toku ljeta i to sve do njihove starosti
od 3—4 godine; premazivati od zemlje pa do visine koju radnik može
doseći rukom. U rasadnicima i u kulturama redovito suzbijati napade
insekata.
3. U toku zime, naročito ako nastupi topli period (bilo u prvoj ili
drugoj polovici zime), prskanje biljaka sumporno vapnenom (kalif ornijskom)
juhom (1 : 40).
4. Dezinfekcija reznica prije sadnje kratkotrajnim potapanjem u
bordošku juhu.
5. Dezinfekcija oruđa, kojim se obavljaju radovi u rasadniku (škare,
noževi i si.) 1% formalinom ili 5°/o fenolom (karbolna kiselina). Poželjno
je da se dezinfekcija obavlja više puta u toku samog rada na izradi
reznica i okresivanju biljaka.
6. Dezinfekcija rana kod okresivanja upotrebom tečnosti Skawinski,
koja se sastoji od 50°/o otopine zelene galice (ferosulfata) zakiseljene 1%
koncentrirane sumporne kiseline.
Summary


In the spring 1956 all over the P. R. of Croatia different kinds of euroamerican
and domestic black poplars were attacked by parasitic fungus Dothichiza
populea Sacc. et. Briand. The disease was found on the following species of poplars
planted in this country: P. e. f. marilandica, P. e. f. serotina, P. e. f. robusta,
Populus berolinensis, P. nigra, P. nigra var italicum and P. trichocarpa. No indication
of resistance to disease on above mentioned species of poplars was observed.
The only species which showed explicit resistance to disease was Populus candicans.
There was found no plant of this poplar infected by fungus.


The author gives a list of infested localities in Croatia. Especially heavy losses
were observed in the district of Osijek the (East Slawonia) where more than 70.000
plants in nurseries were destroyed by this fungus. In several cases the Dothichiza
populea was found attacking´ poplars in good condition and in best stands
for as to the the vigour of growth and development.


Ahe author considers relative high temperature in first half of winter 1955/56
(December, January) to be responsible for damages occured in the following spring.
At the temperature od 14—170 c in December 1955 the parasitic fungus had agreat
importance for its spread. At the same time the poplars beeing out of vegetation
Were unprotected and susceptible to fungus attack. After this critical period there
occured an extremly low winter temperature which caused further damages on
the infested as well as on uninfested trees. The author considers that the coincidence
of the above mentioned as well as the other factors disscussed in this article
(the mistakes made in poplar planting during several last years) were responsible
for the disease spreading in such a degree.