(a)  Distinguish between a field pest and a storage pest. [2 marks] 

 (b) Give two reasons for early harvesting of maize from the field. [2 marks] 

 (c) Describe each of the following methods of crop improvement: 
                              (i)              introduction; 
                              (ii)             cross breeding. [6 marks] 

 (d) List six factors that should be considered in selecting a crop variety for your locality. [6 marks]