Physan 20 and orchid health
 

I was just wondering how everyone applies their Physan 20. Can you apply it directly to the roots? I am assuming this is Ok, but I just wanted to check. What about Vandas? If applied directly to roots, could it harm the plant, or possibly harm a developing spike?

Reason I am asking is that I have one Vanda that had a developing spike that just died off very early on in the development process. I have no idea why...the 'chid is healthy looking with a nice mass of roots. It usually blooms 2-3 times a year.... The only thing I did different was start using Superthrive once a week (before the spike developed), kept up regular fertilizing, and sprayed the roots once with Physan. I did have to move the plant due to Tropical Storm Fay and bring it inside and after barely one day of being inside the spike started looking brown. After I got home from work last night, the spike was a goner.... Any ideas? My other plants in spike/budding have all been fine...they are not Vandas, though. Any thoughts? Could it be somethign else?

Doubt it was Physan 20. I have never experienced any problems with it's use on roots or leaves. I regularly spray the mounts in my Orchidarium with it to stall off the inevitable fungus that comes from wet environments. I doubt it was the Superthrive, either. I've never grown a Vanda in my life, so I am not familiar with what causes spikes to blast like that. But I'm pretty sure it's not one of the two things mentioned here.

Well then I guess it had something to do with me! Not much better but at least I can start getting closer to pinpointing the problem... I think I will post over in the Vanda pages.

Thanks Ross. I might just have to start emailing you directly! JK.... ;)

Go for it! :biggrin: I can only speculate on Vandas. I can't even say for sure I've seen them close up. :bowing

Either it was thrips or the sudden change of weather.Thrips will balst a vanda spike overnite. Bringing in the vanda specially if it was wet from the rain and then into the a/c would have the same end result. Like Ross said ...nothing to do with the Physan 20.
By the way as soon as you see a spike on a vanda in summertime, in fla.,Immediately spray the whole plant like every 3 days to ward of thrips.

This a portion of the package insert for RD-20 which is chemically the exact same material as Physan 20. As you can see it can be used as a soak when transplanting as long as you dilute it as directed on the package insert. Just as Ross sprays frequently, so do I and I love the medicinal fragrance it gives the GH....just my silliness...right, Ross :rofl: :rofl: :scratchhead:

GREENHOUSE DISINFECTANT FOR ORCHIDS &
ORNAMENTALS FOR USE AGAINST FUNGAL,
BACTERIAL, ALGAL AND VIRAL PLANT PATHOGENS
AND THEIR ODORS
RD-20 Greenhouse Disinfectant is a Concentrate and Must
be Diluted Before Use
ACTIVE INGREDIENTS:
n-Alkyl (60%C14, 30%C16, 5%C12, 5%C18) dimethyl benzyl ammonium chloride ............ 10.0%
n-Alkyl (68%C12, 32%C14) dimethyl ethylbenzyl ammonium chloride .............................. 10.0%
INERT INGREDIENTS: .................................................. .................................................. . 80.0%
TOTAL: .................................................. .............................................. 100.0%

ORCHIDS
Seedlings: Soak seedling 2-5 minutes before potting to remove agar. To help prevent damping-off caused by Pythium, Fusarium or Rhizopus,
spray seedlings once per month as preventative maintenance. Spray any time disease is evident with a solution of 1.5 tsp. R-D-20
Greenhouse Disinfectant per gallon of water.
Adult Plants: Spray any time disease is evident with a solution of 2 tsp. R-D-20 Greenhouse Disinfectant per gallon of water. Spray once per
month as preventative maintenance.
Dividing Plants: Remove compost, then soak plans for minutes in a solution of 1 tbsp. R-D-20 Greenhouse Disinfectant per gallon of water.
Operate with wet hands and cutting tools. After division and root trim, soak divisions in the solution for 2 to 5 minutes. Pot in compost drenched
with the R-D-20 Greenhouse Disinfectant solution.
Botrytis Petal Blight: During cool weather, spray plants, flowers and under benches at first sign of spotting on flowers. Normally, weekly
sprayings will greatly reduce or eliminate the botrytis spotting. Use 1 tsp. of R-D-20 Greenhouse Disinfectant per 3 gallons of water.
Cut Flowers: containers. tubes and decorative vases. Recommend flower spikes be hardened in a solution of 1 tsp R-D-20 Greenhouse
Disinfectant per gallon of water during harvesting, storage and shipping to help control the transfer of diseases.
Rots (Such as Erwinia. et al): Remove compost from plant, then soak entire plant 10 minutes or more in a solution of 1 tbsp. R-D-20
Greenhouse Disinfectant per gallon of water. Cut away all rot with treated tool. Soak plant wounds again for 10 minutes in solution. Repot in
drenched compost.
Crown Rot: Spray plants weekly with a solution of 2 tsp. R-D-20 Greenhouse Disinfectant per gallon of water

Wow...thank you for the very thorough information!

Now, I have to learn how to fight Thrips.... I will save that for a new post though! Thanks everyone!!! :)

Thrips are easy....Bayer 3-in-1 concentrate. Dilute and spray! Done deal!

If you plants have been out in the weather we've had lately, I think the very high humidity and constant, record rains these past 2-3 weeks are trying to reek havoc, not letting plants dry out as they should.

For the first time, I've had to spray for fungus. I've lost some new growths, mostly on cats, and a few plants have developed black spots on their leaves but at least one vanda spike was lost - turned slowly brown and dropped its buds. All of these were plants that have been out in the weather. The ones under cover show no such signs of issues.

I'm going to have to do more preventative spraying in the summer months from now on.