ROSE CANE CANKER

Cred ca Burebista are dreptate, pierderile mari la trandafiri in aceasta primavara total aiurea din punct de vedere climatologic se datoreaza unei boli fungice , numita in engleza Canker ( = taciune, cangrena, putrezire).
Ploile din primele zile ale lui martie au favorizat extinderea bolii la nivelul intregii parti aeriene a plantei. De ce cred ca e vorba de aceasta boala? Pentru ca ea a afectat ramurile incepand din partea de jos spre varf si a prins mai mult ramurile mai vechi, unele cresteri noi ramanand neatinse de semnele bolii. La inghet de obicei sensul distrugerilor apar dinspre varf spre baza (sper sa nu spun vreo prostie, imi cer scuze daca gresesc!).

Cauze care pot facilita aparitia bolii:
1. Abateri de la regimul termic pet imp de iarna;
2. Fluctatii drmatice ale temperaturilor pet imp de iarna;
3. Durata perioadei de ger;
4. Momentul anului in care apare scaderea severa a temperaturii;
5. Zilele insorite cu temperature ridicate ale aerului concomitant cu sol inghetat;
6. Adancimea pana la care este solul inghetat;
7. Prezenta vanturilor;
8. Umiditatea scazuta;
9. Lipsa zapezii;
10. Conditiile solului;
11. Lipsa padurilor de protective
12. Rezistenta scazuta la inghet a soiurilor ;
13. Adaptabilitate scazuta a unor soiuri;
14. Diferente in gradul de rezistenta a unor tesuturi;
15. Gradul de stabilizare a plantei;
16. Starea plantei: repaus vegetaativ, stress cauzat de seceta, folosirea in exces a ingrasamantului, prezenta insectelor care raspandesc boala;

Ce trebuie facut?
1. Nu trebuie facut absolut nimic pana primavara tarziu cand cand incep noile cresteri pe lemnul sanatos si vedeti ca pe lemnul vechi nu creste absolute nimic! Inainte de a face ceva verificati daca coroana plantei este vie.Apoi indepartati lemnul afectat.
2. Curatati pana ajungeti la lemn curat, sanatos. Nu lasati nimic din ce este afectat.
3. Dati plantei suferinde sansa sa devina din nou sanatoasa. Taiati doar partea sever afectata, nu si lemnul sanatos.
4. Cu cat va fi mai mare zona infrunzita, cu atat ea va putea produce noi lastari si sa creasca tesuturi noi. Fertilizati corect, si doar daca stiti ca solul duce lipsa de anumiti nutrienti. Nu adaugati ingrasamninte peste cantitatea strict necesara.
5. Mulciti pentru a asigura umiditatea necesara.



ROSE CANE CANKERS
Roses are susceptible to canker diseases whether they grow in the
wild or under cultivation in gardens or greenhouses. Canker
diseases were first reported on roses in Europe in the late 1800s
and were first recognized in the United States in 1917. Although
all aboveground plant parts are susceptible to one or more cankercausing
fungi, the greatest canker damage occurs to the canes.
Cane infections may approach 100 percent where no controls are
practiced.
SYMPTOMS
The first symptoms on the canes are small yellow, dark red, or
purple spots that gradually enlarge and may girdle or partially
girdle the cane. Complete girdling results in dieback or poor
growth of the parts above the affected area. Minute black fruiting
bodies of the canker-causing fungus or fungi are visible in the
cankered areas.
When infection is extensive, cankers may spread down the canes
to the crown, where the fungus then spreads into other canes. In
such cases, the entire plant may wilt, wither, and die.
Penetration and infection occur chiefly through wounds in the epidermis caused by pruning cuts, thorn
abrasions, frost cracks, hail damage, cultivar wounds, insect and rodent injuries, or flower removal.
Broken thorns and leaf and thorn scars also serve as entries for infection. In some instances, the canker
fungi can invade the uninjured, tender epidermis of new growth or dormant buds.
The three most common canker diseases of roses in Illinois are stem blight and canker (also known as
common canker), caused by the fungus Coniothyrium fuckelii (teleomorph Diaplella coniothyrium); brand
canker, caused by the fungus Coniothyrium wernsdorffiae; and brown canker, caused by the fungus
Cryptosporella umbrina (anamorph Diaporthe umbrina).
Brown canker is the most destructive of the three diseases. Outdoor roses–primarily floribundas, hybrid
teas, and hybrid perpetuals–are the most susceptible to brown canker. Rugosa (Rosa rugosa), moss
(variety of R. centifolia), and brier (Rosa spp.) roses show some resistance.