How to Pass Id's to view in has many relation 'laravel'?

I am trying to pass the ids of the sectors in the create form to view it as a dropdown but got this error

in OrganisationsController.php line 52
at HandleExceptions->handleError('8', 'Trying to get property of non-object', 'C:\wamp\www\laravel\scoring-system\app\Http\Controllers\OrganisationsController.php', '52', array('request' => object(Request), 'organisations' => array('_token' => '110iXWQynwOotkUvHvNidphjzrnIcjNOsQCxr6eb', 'organisation' => 'fff', 'sector' => array('1'), 'isin' => 'fffffffffff'), 'sectorId' => array(array('1')))) in OrganisationsController.php line 52

The code :

namespace App\Http\Controllers;                     

use App\Organisation;                               
use App\Sector;                                     
use Request;                                        

use App\Http\Requests;                              
use App\Http\Controllers\Controller;                

class OrganisationsController extends Controller    {

 public function store(Request $request)             
 {                                                   
     //                                              
     $organisations = Request::all();                
     Organisation::create($organisations );          
     $sectorId = array(Request::get('sector'));      
     $organisations->sectors->attach($sectorId);     
     flash()->success('New sector has been added.'); 
     return redirect('organisations');               
 }                                            }   

via Chebli Mohamed