Question

Despite favorable climatic conditions,a farmer's crop failed to give good yield. Give the possible reasons for this

Answer 1

reasons should be that farmer must be not able to do all the agricultural practices in a wright manner . some are :
proper preparation of soil 
timely sowing of seeds
addition of manures and fertilisers
proper climatic conditions
harvesting 
proper storage 
so , farmer must be failed to do one of the agricultural practices

Answer 2

Though there are favorable climatic conditions,a farmer's crop failed to give good yield ,that means that the soil fertility may be less
 or the seeds are not of good quality,
or pests may be destroying the crop
the farmer may not given good manure and fertilizers for the plant