Unable to reactive the game object

Hi, I'm new in Unity, I'm create a plant growing simulation game on android platform. I'm using texture button as my button to trigger a game objects. I was able to set it into inactive state, but unable to reactive it... The following is part of my code in GUI Texture.

 public class FertilizerBTN : MonoBehaviour {
     public static int currTouch = 0; //so other scripts can know what touch is currently on screen
     // Use this for initialization
     public GameObject fer;
     
     void Start () {
         fer =  GameObject.Find("Fertilizers");
         fer.SetActive(false);
     }
     
     // Update is called once per frame
     void Update () {
         if(Input.touches.Length <= 0){
            //if no touches then execute this code
         }
         else //if there is a touch
         {
            //loop through all the the touches on screen
             for(int i = 0; i < Input.touchCount; i++)
             {
                 currTouch = i;
             //executes this code for current touch (i) on screen
                 if(this.guiTexture != null && (this.guiTexture.HitTest(Input.GetTouch(i).position)))
                 {
                  //if current touch hits our guitexture, run this code
                     if(Input.GetTouch(i).phase == TouchPhase.Began)
                     {
                         fer =  GameObject.Find("Fertilizers");
                         fer.SetActive(true);
                         
                           Debug.Log("OnTouchBegan");
                     }
                     if(Input.GetTouch(i).phase == TouchPhase.Ended)
                     {
                         
                          this.SendMessage("OnTouchEnded");
                     }
                     if(Input.GetTouch(i).phase == TouchPhase.Moved)
                     {
                          this.SendMessage("OnTouchMoved");
                     }
                 }
             }
         }
     }
 }

I'm sorry if I'm done some newbie mistakes... Hope to get help soon, please and thank you.