Wheat breeding in Uruguay spans a period of over 80 years at La Estanzuela. Starting with the release first improved varieties in 1918, the national breeding program has successfully bred over dozen new wheat varieties since 1980. The present study was conducted to measure the genetic advance achieved in grain yield in the short cycle varieties. Fourteen varieties covering the period between 1958 and 1997 were evaluated for three years in separate experiments conducted under high and low fertility conditions.||Significant yield advance, 59-60 kg/ha/year of grain under high fertility conditions and 28-34 kg/ha/year under low fertility conditions was estimated to have occurred between 1958 and 1997. It represents an annual gain in yields of 1.63-1.84% and 1.12-1.43% for high and low fertility management respectively. The regression analysis of grain yield conducted over the year of release of a variety explained between 66 and 84% of the variation among varieties under test.||In addition to the genetic advances observed in grain yield,, the national breeding program was successful to introduce moderate level of disease resistance into the newer varieties. However, the increased grain yield was associated with slow decline in the industrial quality characteristics especially percentage of wet gluten and mixing time. Although reduction in quality parameters is not seen as drastic at the present time, yet it will require strong breeding effort to reverse the trend. The study indicated further room for improvement in grain yield, which must be combined with better disease and industrial quality.

Spanish

9911|R99-00BOOK|R97-98PRESE|EE|AGRIS 0102

Jose Juan Caballero

CIMMYT Publications Collection