I am new to Robot, but into embedded development.Wanted guidance on best suitable robot kit or should I develop one from scratch that I wanted to use programmed through ROS in agriculture for monitoring crops like diseases,growth etc and various features that I’ll add using Computer Vision as needed.Wanted to know is it advisable to use kit or build from scratch ,also guide any thing different which is better compared to ROS.
Now, from the other hand, if you want faster results (could be harder at the beginning) you could buy a robot kit. Since you would like to build and agriculture monitoring robot, I guess it would have to be a platform with several wheels that is carrying a camera? Here you can find a lot of kits: https://www.robotshop.com/en/wheeled-development-platforms.html
From those, maybe I would suggest this one:
It’s not ROS, but it is still programmed in Python or Dragit, which should be simple. You could, for example, programming to move on the crops field tracking some lines and similar.
Also you can checkout a lot of home made project in Robots section. And when you finish your robot, you should post it there, and you could even win a prize!
As @igor_X stated, by building the robotic platform yourself you will definitely learn more and it will be much easier for you to add new features as needed. You could either start with an unassembled kit and add new modules according to your needs or buy each component yourself and create the robot from scratch.
If you are not really into building things you could simply buy the robotic platform assembled, there are many available in the store, and some of them are ROS based, like these:
Keep in mind these are very robust platforms hence the price.
Also, as you mentioned you want the robot for agriculture applications I’d recommend checking out the UAVs & Drones section because I think they are better suited for this kind of tasks. Or if you want to build one yourself you could look at the How to Make a Drone / UAV tutorial series which lists all the things you need and will guide you to the whole process.