Phrags are melting :(

[Forever-mango]

Currently in Sydney its in the middle of winter. Sometimes we get very wet weeks but this week we got some nice sunshine. Nights sometimes get low around 2*C and daytime temp is 17*C. This week i have noticed some of my Phrag with the leaves melting. When you squeeze the leaves, water comes out like a sponge. I havent watered them for 3 days now, they are under cover but still get lots of sunlight. Im using a mixture of Small perlite, small bark, small coco chips, and chopped up moss. The Paphs. grow in the same area and with the same mix. The Paphs seems to love the area and are starting to bloom. But somehow the Phrags have this issue

So far I have strayed them with Mancozeb and have put them on the side for the time being.

Hope someone can help me
Stephen

 

[paphioboy]

I'm sorry to say that looks like a really bad case of bacterial rot (Erwinia cypripedii, mst probably)... It is a very difficult disease to cure. All infected tissue must be removed (especially brown parts at the leaf axils). If left, it will spread and kill the whole fan of growths..

 

[John M]

That's frost burn. Just because it gets down to +2*C, doesn't mean that there will be no localized frost formation. Believe me, I know frost damage. My whole greenhouse froze in 2008. Temps were not severe; but, they were at least down to -1*C and that's all it took to kill most everything....although, there were some surprising survivors. Check out this thread over at Orchid Source Forum from March 2008 to see photos of frost damage.http://forum.theorchidsource.com/ubbthreads.php/ubb/showflat/Number/46213/Searchpage/1/Main/3720/Words/disaster/Search/true/Disaster_New_updated_photos_Ma.html#Post46213

Even though a bacterial disease did not cause the death of the tissue, now that the frost has killed some tissue, bacterial rot will likely move in to a lot of the dead tissue sites. Watch the plants closely and remove any parts that seem go "watery" and develop an unpleasant smell. Then, dust the wound with cinnamon. Other areas that were damaged will simply dry and the plant will seal the area between the dead tissue and the remaining live tissue. Resist squeezing the leaves to make the moisture come out "like a sponge". You are just causing more damage to otherwise healthy tissue and/or, you are enabling the opportunistic bacterial pathogens to spread to other leaves. Erwinia is immediately identifiable by it's horid, tangy smell. When you smell it, find it and remove it....dust with cinnamon. Over the next few weeks, many plants will recover and begin growing again; although, it will take some time (years?), for them to outgrow the visible damage/scarring. Also of course, cover the plants at night and keep them warmer than you have been to prevent further damage or stress.

 

[Rick]

If the plants really experienced 2C then they got real cold, and as John said tissue damage from cold.

Do the effected parts have a sweet, fermentatious smell? That is a characteristic of Erwinia as Paphioboy pointed out (along with the wet brown look). That is a bacterial rot species. You might try antibiotics. I use Dragons Blood from www.shopgonewild.com and cinnamon after surgical removal of the effected parts.

 

[Forever-mango]

I have removed all dead or looked infected tissues. I have placed them in a warmer area in the yard. It must be the cold morning last week. It was -2*C and was the coldest day in 55 years! Then from what John has identified its frost damage, i can clearly say its frost. Because last week we did have frost and was frost until 10am! I see some damage on some of my Dendrobium speciosums as well. The Phrags (besseae crosses) are indoors, they seem to be ok. Thanks for the info and i will try to prevent it

John, how is the greenhouse now? I thought my plants was bad, im really sorry for that hit in 2005 Is there a way to prevent this from happening when i dont have a greenhouse?

 

[John M]

It was -2*C and was the coldest day in 55 years! That'll do it, for sure!

John, how is the greenhouse now? Restocked; but, I'm a lot poorer!I thought my plants was bad, im really sorry for that hit in 2005 Is there a way to prevent this from happening when i dont have a greenhouse? I know that Florida citrus growers place "smudge pots" all throughout their orchards when frost threatens. Basically, these are bonfires in steel drums; or something like that. Or, you could strategically place heat lamps in the area of your plants, just to take the edge off the cold and prevent frost. Obviously, the basic idea is to provide a little heat in the plant area to keep the frost away. Good luck.

..

 

[NYEric]

Poor babies! ity:
If you have some captan or in a squeeze cinnamon powder, put that on the cut leaf ends as a drying agent to prevent rot.

 

[Forever-mango]

Thanks guys.

I researched on Phrags and they need warm winters, so I place them in the bathroom with my Phals. They are doing alot better and hopefully recover.

 

[KyushuCalanthe]

Sorry to see such loses. I lost my one Phrag the same way - they hate cold and wet!

 

[NYEric]

Sorry to see such loses. I lost my one Phrag the same way - they hate cold and wet!

ONE!?!?!?! :viking:

 

[KyushuCalanthe]

ONE!?!?!?! :viking:

Yeah, most are just too darn large growing and besseae would melt in our summers....maybe I'll give one a whirl again sometime.