Gaps between farmer and attainable yields across sunflower growing regions of Argentina

A.J. HALL; C.FEOLI; J.INGARAMO; M:BALZARINI

Lincoln, NE

Conferencia; Water for Food 2011 Global Conference; 2011

University of Nebraska

Yield gaps between attainable (derived from comparative yield trial data) and farmer (derived from reporting district [county] data) yields were computed for 8 regions of Argentina in which sunflower is grown under rainfed conditions, using BLUE values for both variables estimated from 5 to 9 years of data per region. These gaps were significant (p = 0.05 to p = 0.001) for all regions and ranged from 0.37 to 1.18 t ha-1 across regions, for a country average of 0.75 t ha-1 , equivalent to 41% of the mean country yield of 1.85 t ha-1.  Individual field yields were available for 5 regions, and gaps estimated using this variable were smaller (but never nil) than reporting district gaps in 3 regions. Mean yields for the top decile of comparative yield trial data ranged from 3.2 to 4.2 t ha-1 across regions, and the highest yields for this decile ranged from 3.9 to 4.8 t ha-1. A notable feature of both individual field and comparative yield trial data was their variability. The mean relative contribution of the trial effect to non-error variance exceeded 89% across regions, dominating the contributions of genotype and of genotype by trial effects. We conclude that the farmer/attainable yield gap for this crop justifies further research into its causes aimed at reducing regional gaps, and that mean comparative yield trial data provides a good benchmark for attainable yields, of greater practical value than mean trial top decile yields or the highest recorded value for the last variable.