seed farm yield 
1    1 32.98924
2    1 30.87648
1    2 27.82418
2    2 31.39945
1    3 24.57806
2    3 29.16998
1    4 30.13945
2    4 26.69091
1    1 34.94947
2    1 32.46272
1    2 28.50166
2    2 35.28636
1    3 23.84696
2    3 27.15175
1    4 28.74726
2    4 27.31587