why create dynamic mesh with shadows ?

When i create mesh and uvmap with script, there is some shadows when playing game. But if i use a plane and textured it , it works great.

How can i create mesh with no shadows?

Here is the code blew:

 using System;
 using System.Collections.Generic;
 using UnityEngine;
 
 public enum Blocks : byte
 {
     Dirt=0,
     Stone = 1,
     coal_ore = 2,
     iron_ore = 3,
     gold_ore = 4,
     Air = 255
 }
 
 public class Main : MonoBehaviour {
         
     public WorldMain worldMain;
     
     public bool isPause = false;
         
     public Texture2D[] worldTextures;
         
     List<Vector3> vectices = new List<Vector3>();
     List<Vector2> uvs = new List<Vector2>();
     List<int> triangles = new List<int>();
     int drawRectIndex = 0;
     
     private Chunk m_chunk;
     
     void Start()
     {        
         worldMain = new WorldMain( this );
         worldMain.init();
         
         System.Random ra = new System.Random();
         
         int areaSize = 32;
                 
         for( int i=-areaSize;i<areaSize;i++)
         {
             for( int j=-areaSize;j<areaSize;j++)
             {    
                 drawRect( i , 0 , j , (int)ra.Next( 0 , 5 ) );    
             }    
         }
         
         renderDraw();
     }
                 
     void drawRect( float x , float y , float z , int blockType )
     {
         vectices.Add( new Vector3( x, y , z ));
         vectices.Add( new Vector3( x, y , z + 1 ));
         vectices.Add( new Vector3( x + 1, y , z ));
         vectices.Add( new Vector3( x + 1, y , z + 1 ));
         
         BlockUVCoordinates blockUV;
         worldMain.m_BlockUVCoordinates.TryGetValue( blockType , out blockUV);
         
         float u = (float)blockUV.data[ (int)BlockFace.Top ].x;
         float v = (float)blockUV.data[ (int)BlockFace.Top ].y;
         float w = (float)blockUV.data[ (int)BlockFace.Top ].width;
         float h = (float)blockUV.data[ (int)BlockFace.Top ].height;
         
         uvs.Add( new Vector2( u, v ));
         uvs.Add( new Vector2( u, v + h ));
         uvs.Add( new Vector2( u + w, v ));
         uvs.Add( new Vector2( u + w, v + h ));
         
         triangles.Add( drawRectIndex + 0 );
         triangles.Add( drawRectIndex + 1 );
         triangles.Add( drawRectIndex + 2 );
         triangles.Add( drawRectIndex + 3 );
         triangles.Add( drawRectIndex + 2 );
         triangles.Add( drawRectIndex + 1 );
         drawRectIndex += 4;
         
     }        
   
     void renderDraw ()
     {
         GameObject world = GameObject.Find( "world" );
         
         MeshRenderer meshRenderer = (MeshRenderer)world.GetComponent<MeshRenderer>();
         MeshFilter meshFilter = (MeshFilter)world.GetComponent<MeshFilter>();
         MeshCollider meshCollider = (MeshCollider)world.GetComponent<MeshCollider>();
         Mesh mesh = meshFilter.mesh;
         
         meshRenderer.material.mainTexture = worldMain.WorldTextureAtlas;
             
         mesh.vertices = vectices.ToArray();
         mesh.uv = uvs.ToArray();
         mesh.triangles = triangles.ToArray();
         mesh.RecalculateNormals();
         
         meshCollider.sharedMesh = mesh;
     }
 }