Nope. It won't. Why? because "picturebox1.Image" is a string. Not an image.
If you have the field configured in your database, then try:
SqlConnection conn = new SqlConnection(dbconnstr);
conn.Open();
string qry = "INSERT INTO myTable (myImageField) VALUES (@PD)";
SqlCommand sqlcom = new SqlCommand(qry,conn);
MemoryStream ms = new MemoryStream();
pictureBox1.Image.Save(ms,System.Drawing.Imaging.ImageFormat.Bmp);
sqlcom.Parameters.AddWithValue("@PD", ms.ToArray());
sqlcom.ExecuteNonQuery();