Farmer Participatory Early-Generation Yield Testing of Sorghum in West Africa: Possibilities to Optimize Genetic Gains for Yield in Farmers’ Fields

Abstract

The effectiveness of on-farm and/or on-station
early generation yield testing was examined to
maximize the genetic gains for sorghum yield
under smallholder famer production conditions
in West Africa. On-farm first-stage yield trials
(augmented design, 150 genotypes with subsets
of 50 genotypes tested per farmer) and secondstage
yield trials (replicated a-lattice design,
21 test genotypes) were conducted, as well as
on-station a-lattice first- and second-stage trials
under contrasting phosphorous conditions.
On-farm testing was effective, with yield showing
significant genetic variance and acceptable
heritabilities (0.56 in first- and 0.61 to 0.83 in second-
stage trials). Predicted genetic gains from
on-station yield trials were always less than from
direct testing on-farm, although on-station trials
under low-phosphorus and combined over multiple
environments improved selection efficiencies.
Modeling alternative designs for on-farm
yield testing (augmented, farmer-as-incompleteblock,
multiple lattice, and augmented p-rep)
indicated that acceptable heritabilities (0.57 to
0.65) could be obtained with all designs for testing
150 progenies in 20 trials and 75 plots per
farmer. Ease of implementation and risk of errors
would thus be key criteria for choice of design.
Integrating results from on-station and on-farm
yield testing appeared beneficial as progenies
selected both by on-farm and on-station firststage
trials showed higher on-farm yields in second-
stage testing