I received the following rejection for my 1st application as a contributor for iStock. 

'At this time we regret to inform you that we did not feel the overall composition of your photography or subject matter is at the minimum level of standard for iStockphoto. Please take some time to review training materials, resources and articles provided through iStockphoto. The photographs provided in your application should be diverse in subject matter, technical ability and should be your best work. Think conceptual, creative and most important think Stock photography. Try to avoid the average eye level push the button perspective of a common subject. Try and impress us, we want to see how you stand out from the crowd. '

These are the photos of my 1st submisssion
http://s727.photobucket.com/user/mbjayasekara/library/reject [nofollow]

These are the photos I'm hoping to submit in my 2nd application. Need your critiques on these to find the best 3 photos in order to submit. Hope that minimum 3 from these will be suitable for the 2nd submission.
http://s727.photobucket.com/user/mbjayasekara/library/iStock [nofollow]

Need your support on the good and bad of the new photos.
Thanks in advance! 

I wouldn't submit any of these for application photos. In addition to technical flaws in some (I looked at the one with foreground wheat stalks, for example, and it's noisy, over processed and shot at ISO 800), the subject matter and composition just don't work as stock images.

In general, especially for applications, stay away from flowers, butterflies, sunsets, puppies & kittens (unless you're a specialist in any of these). Ensure the images are in sharp focus with good color and contrast - save the artsy stuff and clever processing for later (if you can do a good job at it). Ensure you have decent lighting - outside or studio. Have three different subjects. Shoot at the lowest ISO possible, stay away from noise reduction or sharpening.

All of these rules can be broken, but when you're trying to get accepted, following them increases your chances

Yes, JoAnn is correct, as usual.