Agriculture Reference
In-Depth Information
of two modern varieties from the 1990s, grown as a mixture for 15 years
on an organic farm in the Netherlands (see Serpolay et al. [35] for more
details on the varieties).
Before harvest, each of the farmers were asked to select 20 spikes (from
different plants) in the 2 replicates of the 3rd generation version of each
varieties. Phenotypic traits were measured at maturity for these selected
individuals and for 20 other individual plants chosen at random from each
replicate of the origin and 3rd generation version. These traits included
plant height (PH), last leaf-to-spike distance (LLSD), spike length (SL),
grain weight per spike (GW/spike), and thousand kernel weight (TKW).
LLSD was considered important by farmers based on their observations,
because a longer LLSD distances the spike from the canopy and poten-
tial foliar disease spores, may reduce humidity around the spike making
conditions less favorable to disease development, and may improve grain
fi lling under conditions where leaves no longer photosynthesize due to
drought, heat or disease stress. The other individual plant traits were cho-
sen based on the descriptors used for variety registration (which evaluate
the distinctiveness, uniformity and stability of varieties), in order to char-
acterize farmer varieties with respect to modern varieties.
The versions were then compared (origin vs. 3rd generation without
selection, and selections within the 3rd generation vs 3rd generation with-
out selection) for these phenotypic traits. The analysis of on-farm evo-
lution and selection differentials were done using an ANOVA model: Y
= u + farm + rep(farm) + variety + version(variety) + farm*variety +
farm*version(variety) + error. Tests of differences between versions were
done using Tukey's multiple comparison procedure for two cases: (i) be-
tween the original and 3rd generation (without conscious selection) ver-
sions within each farm and variety; and between selections and the 3rd
generation (without conscious selection) version within each farm and
variety. In 2009-2010, progeny head-rows of selected and non-selected
spikes of all four farmers varieties and Renan were grown at the research
station of INRA le Moulon. Plots of selected and non-selected progeny
of Rouge de Bordeaux (RB), Blés de Redon (RD) and Renan (RN) were
grown on one participating farm to analyze the response to selection. Re-
sults from the on-farm trial are presented here.
