Hey Bot...
 

What the heck is the white white stuff on the pix below? And can I get rid of it without killing the plant? Every Petunia we’ve had has died due to the sudden onset and quick spread

The pix is 640x480 resolution

http://mountaintreats.com/pix/petuna.jpg

Thanks!!!!!

Re: Hey Bot...
 

That's a Plantman question. Landscape people are the practical side. Botanists count angels on pinheads.

B

PS I got the following off an NC State website. NC State has excellent plant path research.

Botrytis Gray Mold


The most common disease of greenhouse floral crops is gray mold. Gray mold is cause by the fungus Botrytis cinerea. It is a common fungus, with a very wide host range and can persist in the greenhouse year-round. The fungus produces a large amount of spores that move throughout the greenhouse via air currents. Under environmental conditions of relative humidity at or above 85%, little or no air circulation and free water on the leaf surface, the fungal spores land on plant surfaces, germinate and penetrate the host. The symptoms of gray mold vary depending on the host and the environmental conditions associated with the host. In most cases the disease is characterized by the production of leaf spots, flower blight, bud rot, stem canker, stem and crown rot, cutting rot, damping off and in extreme cases, plant death. The fungal growth is characterized by the presence of fluffy gray/brown mycelium that produces a cloud of spores if disturbed. Affected tissue is soft and brown, and sometimes has a water soaked appearance. This disease can be anything from a common nuisance to an economic disaster depending on the host and the conditions under which the crop is grown.



Powdery Mildew


Powdery mildew is one of the most wide spread diseases in the floriculture production industry. It is caused by the fungus Oidium spp. whose spores are easily spread by physical movement and air currents. In most cases, symptoms of this disease are relatively easy to identify. The disease is characterized by the fluffy white fungal growth on the leaves, stems, and flowers of infected plants. The disease typically shows up on leaves first and if left unchecked it will spread to the stems and flowers. Tissues infected with powdery mildew can eventually become necrotic. This disease is responsible for significant economic losses in the greenhouse. Powdery mildew tends to be more of a problem later in the growing season when night temperatures get cooler. High humidity is also necessary for development of the fungus. However, it depends on the individual organism as to when and where the disease shows up.



Downey Mildew


The fungus that causes Downey Mildew is more specific to its hosts than the fungus that causes Powdery Mildew. The fungal spores, which are usually short lived, are spread though the air and are able to infect a susceptible host if free water is present. High humidity is required for sporulation and the growth of the fungi is favored by cool temperatures (40-60° F). The fungus also produces a sexual spore that can survive in dry conditions, enabling the fungus to live in the absence of a host. Symptoms of a Downey Mildew infection include the appearance of sporulation on the undersides of leaves that is sometimes angular in shape and delimited by veins. Pale yellow or necrotic areas are sometimes visible from the upper side of the leaf. In some plants when the young shoots are infected the fungus may become systemic and cause stunted growth, malformations and yellowing of plant tissue.

Thanks Doc! I wouldn't have guessed at it being mold. The other mold I’ve seen, and that I thought was mold, was on old food in the fridge, and that looked like the food was knitting itself a sweater..... Hmmmm. Not so different after all.

I can't really tell as the res is a little off. I would venture to agree with it being mold, however, it could just as well be mealy bug.

When it comes to exterior landscape, I am limited in identifying pests, molds, etc....we specialize in interior applications of shade raised foliage. For the normal home depot shopper, there is no difference, but there is.

Houston Horticulture tips
 

Since I live in the nasty insect and mold capital of the world, Houston, I can give you a couple of tips. Get a piece of black paper and shake the stuff on it. If the stuff moves, its bugs, so spray it with what ever diluted nerve gas is acceptable for the plant. If it doesn't move, its fungus. Hit it with whatever fungicide has the word "white stuff" on the label. If that still doesn't kill it, clip a bunch of it off and throw it in the yards of neighbors who piss you off.

Re: Houston Horticulture tips
 

I like it, Kirk.

Guerilla botany!

In the same light I could just gift them a petunias from the same place we got these. The literature indicates it’s endemic to greenhouses. The neighbors would enjoy the gift. Then a week later, voila a Trojan outbreak....

Speaking of "Trojans" I should think a certain prophylactic company would wish to sign-up Brad Pitt.

Bot

PS Hijacked!

I'm not entirely sure I understand what the reference is, but I think I remember hearing that Brad Pit is or was or forever will be in a movie about..................botany? ;)

Re: Re: Houston Horticulture tips
 

I've got a deal going to bottle Houston air and sell it up in Vermont to kill gypsy moths.

Oh lordy, don't get me started with the puns.

I wonder if Trojans would stretch over their tall members. Standing erect before plunging into the warm depths that await a man's forthrightness? Despite frenzied battle with hairy darkness, do they have a reservoir in their heads for seminal ideas?

Bot

I think your just getting in deeper and deeper.