I am doing a grass (field of wheat) and I added a wind. My windmill is affected by the wind but wheats are not!. How can I fix this?

I am sharing my wind and particle system options. I want my all objects to be affected by the wind.

These are screenshots of the particle system settings: 

[![enter image description here][1]][1]


[![enter image description here][2]][2]


[![enter image description here][3]][3]


and this is my wind options:

[![enter image description here][4]][4]


  [1]: https://i.sstatic.net/XSwzw.jpg
  [2]: https://i.sstatic.net/zATfG.png
  [3]: https://i.sstatic.net/114cp.png
  [4]: https://i.sstatic.net/dwxTe.png
where i am doing wrong?