Table 3. Rate of growth of wheat yield by mega-environment, Elite Spring Wheat Yield Trial, 1964–1995.

Period  
ME1
 
ME2
 
ME4
 
ME5
1964–1978  
 
 
 
 
 
 
 
    Percent per year  
1.22
 
1.72
 
1.54
 
1.41
    Kg per year  
71.6
 
81.5
 
32.4
 
34.9
1979-1999  
 
 
 
 
 
 
 
    Percent per year  
0.82
 
1.16
 
3.48
 
2.10
    Kg per year  
53.5
 
62.5
 
87.7
 
46.1