First of all, welcome to DPChallenge. Congrats on tossing in that first entry. Now, we look forward to many, many more.
Camera Work/Technical: I think that choosing f/11 for this shot was a pretty good idea, thus trying to keep all aspects of the image nicely focused. Even still, it looks like you were a bit too close to the flower by the fact that you lost focus on the petal in the front.
Lighting: Your lighting isn't bad, especially for the harsh, natural lighting that you chose to shoot in. Still though, the lighting is a touch on the hard side, with bright highlights and hard shadows. This really takes away from the silky-smooth feel that you were going for.
Composition/Content: While I'm no stickler for the 'rules' of photography, I do feel that this is far too centered for such a common-place image. You'll find that pictures of flowers and other common subjects will suffer in their score around here unless the image and the composition are both very spectacular. I do agree with dtremain that this would have been stronger with a square crop.
My Opinion: 5.15 is a pretty strong place to start with a first entry. That leaves much room for improvement, but it also shows that the voters didn't absolutely hate what you offered.
Thank you for the opportunity to provide a critique on your entry,
Eric
A very attractive choice of flower. The varying degrees of direct lighting and shadow play an interesting contrast, however the light level between the two is a bit too severe. A better choice in treating the background could also improve the image - while an indistinct backdrop makes a photo interesting in this case I don't have a clear idea what the background is (I think it's running water?)
Beautiful flower. A little too much contrast in the shot for me. You might try taking the picture a little later when the sun isn't directly striking the subject.
Really really great. The colors are fabulous and I love the bit of red to contrast the yellow. I wish your angle was a bit different and this could be perfect.