Page 257 - Area 9 - Relevant Document

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3. Plot 1 planted to variety A and Plot 2 planted to variety B.
4. Grain yield per plot is measured
5. One with the higher yield judged as the better variety
6. The procedure is simple and done out of common sense but
with 1 important flaw
IT PRESUMED: that the cause of the difference in yield is caused by
the varieties and nothing more: which is not true.

WHY: Because even if the same variety were planted in the same plot,
there will always be a difference in yield. Due to the following:

Soil fertility

Moisture
Damage done by insects

Diseases

Birds etc, weeds,

So the breeder designs a procedure that will decide whether the
difference is due to varieties or other factors.

LOGIC:

Two varieties planted in two adjacent plots would be considered
different in their yielding ability only if the observed difference in yield
is larger than what is expected if the two plots are planted to the
same variety.

Thus the researcher needs also to know the difference in yield
between the two plots planted to the same variety.

REPLICATION

 This is very necessary to obtain a measure of experimental
error
 Experimental error could be measured only if:
o at least 2 plots are planted to the same variety or
receiving the same treatment\

IMPORTANCE OF REPLICATION

 Assume you want to evaluate the influence of Bio-organic
fertilizer on eggplant so you prepared two plots . One plot was
applied with bio organic fertilizer and the other was not
applied. At harvest time you observed a better yield on the plot
treated with bioorganic fertilizer than the one not applied with
bio organic fertilizer.