Joint International Conference on Long-term Experiments ...

Yields losses, spring wheat (%)
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10
0
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3% y = 0.4101x 2 - 1645.2x + 2E+06
R = 0.4791 *
10 % y = 1.0655x 2 - 4267.5x + 4E+06
R = 0.7760 **
1996 1997 1998 1999 2000 2001 2002
5% y = 0.8161x 2 - 3269.5x + 3E+06
R = 0.7144 **
3% 5% 10%
Figure 4. The evolution of relative yield losses (1996 – 2002)
Tabel 4 Yield losses due pollution with petroleum in spring wheat (q/ha)
1996 - 2002
Years
No. Variant
Yield
Semnification
Crt. (V)
1996-2002
(%) q/ha Difference V V x Y
1 0 11,5 - - -
2 1 9,6 -1,1 o -
3 3 8,2 -3,3 ooo o
4 5 6,5 -5,0 ooo ooo
5 10 5,2 -6,3 ooo ooo
D.L. Variant Variant x Years
(V)
(VxY)
5 % 1,0 2,7
1 % 1,5 3,6
0,1 % 2,1 4,8
If we sum up all this data we see that the annual yield losses loose their statistical value
after the 7 th year of controlled pollution, for a 1 % concentration, after the 8 th year in 3
% and 5 % petroleum concentration, and in the 9 th year for a 10 % concentration.
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