In the point WIDER ADAPTABILITY it is written that variety is more economical and this method reduce cost of crop preoduction. Then why would a farmer need crops that would be cheap and will put them into loss. Please explain in an elaborated manner.

Dear student,

Your question appears to be incomplete, there is no such point starting  with wider adaptability .
Recheck your question and please be a little specific so that we can provide you with some meaningful help. Looking forward to hear from you again!
Regards