1) Wheat doesn't require that much water which is got during kharif season,it would probably wilt.( Wilting is the loss of rigidity of non-woody parts of plants)
2) It requires cooler climates,which is not available during the kharif season.
3) The young plantlings can't withstand the winds which are found during the season & would sway down,once they are fallen,the crop is wasted.
4) Wheat doesn't require that much of light as found during kharif season,moreover it requires medium intensity & shorter days in the initial stages,which are not found in kharif season.One will get very low production & the plants can be diseased.