Try this :
string newString = string.Empty;
char[] input = "Hi In my applcation for example there are 160 characters or more .... i want to split after 50 characters in next line if hi i want to break after the completion of word.".ToCharArray();
int toSplit = 50;
for (int i = 0; i < input.Count(); i++)
{
if (i % toSplit == 0 && i != 0) newString += Environment.NewLine;
newString += input[i].ToString();
}
label1.Text = newString;