An evaluation of F1 hybrid winter wheat genotypes produced using a chemical hybridizing agent

In experiments harvested in 1985 and 1986 the grain yields of 61 F 1 hybrids among winter wheat varieties and advanced breeding lines were 5·9% greater than the yields of the best parents. In a trial with 430 hybrids in 1986, the hybrids yielded 3·6% more grain than the best parents. Among these 430 hybrids heterosis for yield was greatest for those from the lowest yielding parents. This result is taken to indicate that among these genotypes most genes for high yield have been fixed in the highest yielding parents. The hybrids had slightly fewer ears/m 2 , but more grains per ear and heavier grains than the highest yielding parents. They yielded more straw as well as more grain. The results are compared with those from other studies and it is concluded that yield advantage of F 1 hybrids so far tested is not generally sufficient to justify their introduction into U.K. agriculture.