Agriculture Reference
In-Depth Information
tests the most promising populations for their farm and a larger number of
populations are tested on a central farm for each region. This network of
on-farm trials will permit an analysis over multiple locations and years for
each family and exchanges among participating farmers in order to pro-
vide quantitative and qualitative information on the different families to
aid in making selection decisions. This new strategy is the result of farm-
ers and researchers learning during the fi rst years of the
Croisements du
Roc
project and during the FSO project and the lessons taken from these
two experiences and new methods for collaborative plant breeding are de-
scribed at the end of the discussion.
11.3 RESULTS
11.3.1 FARM SEED OPPORTUNITIES
There were often similar levels of intra-varietal variability between farmer
and modern varieties, indicating that the strong selection for genetic ho-
mogeneity to meet regulatory criteria had little impact on the phenotyp-
ic variability of certain traits when assessed on organic farms [35]. This
could be due to high levels of micro-environmental variation within plots
or residual genetic variation that is not expressed in conventional trials.
Several farmer varieties had high values of traits related to productivity
outside their region of origin, which underlines the need for experimenta-
tion and exchange across regions with diverse material in order to find and
develop appropriate varieties for organic systems [35].
In general there were fewer and more moderate signifi cant differences
due to on-farm evolution without selection than there were signifi cant se-
lection differentials (see Figure 2). Natural selection increased plant height
(PH) twice and decreased it 3 times, with non-signifi cant differences 10
times, while selection differentials for PH were signifi cant for all varieties
and all farms except for ZH at farm HF and was always in the direction
of increasing plant height. Natural selection decreased the LLSD twice
and had no other signifi cant differences. LLSD was more variable, with
fewer signifi cant selection differentials, and signifi cant changes in both
directions. Natural selection increased GW/spike twice and decreased it
