Texturing -> Unity3d Plane and Blender Plane

I’m applying the same texture to two planes. One was created in Unity3D and the other in blender. The texture applied to the plane create with Unity3D is streched, which is the effect I need, but the other one, I can only see a small section of the image. Should there be a different code for each of the planes (what is missing) or do I need to change something in the inspector of the plane made with Blender?

Here’s how I’m applying the texture:

Texture2D tex;
byte[ ] ytes;
ytes=System.IO.File.ReadAllBytes(genInfo.imgLocal);

tex=new Texture2D(1,1);
tex.LoadImage(ytes);

planeObject.renderer.material.mainTexture=tex; //Works !!!
mainObject.renderer.material.mainTexture = tex; //Doesn’t work

My thanks in advanced

Did you UV map the plane in Blender?

No, I didn’t

In case softwizz wasn’t clear, you need to UV map the plane in Blender, or write code to assign that data manually.

yes, but, isn’t the code I posted here enough to “assign that data manually”?

No, you still need to uv unwrap the mesh.