ARCore Rotation not working on swipe with one touch.Why?

From the below code the zoom is working with two fingers but my rotation is not working using single swipe.For testing i added a text.The text is getting updated with "One touch move" when I swipe the screen.
Cannot understand the zoom is working but the rotation not working.Any help?

Code (CSharp):

1.  void FixedUpdate()
2.      {
3. //I Have increased to higher values no use
4.         public float rotspeed=100f;
5.  
6.  
7.         if (Input.touchCount > 0 && isLocked==true)
8.           {
9.               var touch = Input.GetTouch(0);
10.              
11.                 if ((Input.touchCount == 1 && Input.touchCount < 2 && Input.GetTouch(0).phase == TouchPhase.Moved) && !EventSystem.current.IsPointerOverGameObject(touch.fingerId) )
12.                      {
13.                 // Get movement of the finger since last frame
14.  
15.                          Debug.Log("One touch Move");
16.                          Vector2 touchDeltaPosition = Input.GetTouch(0).deltaPosition;
17.                 Messagetxt.text = "One touch Move";
18.  
19.            
20.               this.transform.Rotate(Vector3.up, -touchDeltaPosition.x * rotspeed * Time.deltaTime, Space.World);
21.            
22.  
23.  
24.                      }
25.  
26.  
27.  
28.             if (Input.touchCount == 2 &&  !EventSystem.current.IsPointerOverGameObject(touch.fingerId))
29.                      {
30.  
31.  
32.  
33.  
34.  
35.                         // Store both touches.
36.                         Touch touchZero = Input.GetTouch(0);
37.                         Touch touchOne = Input.GetTouch(1);
38.  
39.                         // Find the position in the previous frame of each touch.
40.                         Vector2 touchZeroPrevPos = touchZero.position - touchZero.deltaPosition;
41.                         Vector2 touchOnePrevPos = touchOne.position - touchOne.deltaPosition;
42.  
43.                         // Find the magnitude of the vector (the distance) between the touches in each frame.
44.                         float prevTouchDeltaMag = (touchZeroPrevPos - touchOnePrevPos).magnitude;
45.                         float touchDeltaMag = (touchZero.position - touchOne.position).magnitude;
46.  
47.                         // Find the difference in the distances between each frame.
48.                         float deltaMagnitudeDiff = prevTouchDeltaMag - touchDeltaMag;
49.  
50.  
51.                         float scale = deltaMagnitudeDiff * perspectiveZoomSpeed * Time.deltaTime;
52.  
53.  
54.                         Vector3 tt;
55.                         tt.x = scale;
56.                         tt.y = scale;
57.                         tt.z = scale;
58.                 if (this.transform.localScale.x > 0 && this.transform.localScale.y > 0 && this.transform.localScale.z > 0)
59.                         {
60.                     this.transform.localScale += new Vector3(-scale, -scale, -scale);
61.  
62.                         }
63.  
64.                 if (this.transform.localScale.x < 1 && this.transform.localScale.y < 1 && this.transform.localScale.z < 1)
65.                         {
66.                     this.transform.localScale += new Vector3(scale, scale, scale);
67.  
68.                         }
69.  
70.                 if (this.transform.localScale.x > 3 && this.transform.localScale.y > 3 && this.transform.localScale.z > 3)
71.                         {
72.                     this.transform.localScale += new Vector3(scale, scale, scale);
73.  
74.                         }
75.  
76.  
77.  
78.                 }
79.  
80.            
81.  
82.    
83.                
84.            }
85.  
86.  
87.      }

 

I am using the later ARcore sdk with HelloARcontroller for placing the object on real world