Oilseed rape grain yield productivity increases with hybrid varietal types: A first balance sheet with post registration tests in France and in Europe

Abstract

Since 1994 several oilseed rape hybrid types were proposed to farmers. Following registration experiments, Cetiom and different equivalent institutions in European Union have tested them in different post registration national networks. Grain yield productivity increases were demonstrated and a first synthesis could be done to check avantages and difficulties which had occurred. For winter types, Hybrid Composits were widely used, mainly in France and in the United Kingdom. Grain yield increases were important in the South and West part of France where their market shares increased up to 50-80%. Nevertheless, many fecondation problems occurred in several places all over Europe. Reasons of such problems were difficult to identify. Several factors, as cold temperatures, nutritionnal competitions, pollen avaibility may be involved to explain low seed sets. Restored Hybrids made with the NPZ hybridation system were successfully tested widely, and has reached significative market shares during 1999-2000 season. Less experiments were carried out with others hybrid types (Ogu-INRA Restored Hybrids, Mixed Hybrids). Ogu-INRA Restored Hybrids reached the highest grain yield levels but users are waiting for lower glucosinolates seed content hybrids which would come in the next future. Performances comparisons among countries have to be done carefully. Productivity increases with hybrid types could have been over estimated depending of pollinic environments or plot size and possible neighbouring effects. For France, results from field trials networks are coherent with results coming from postal surveys. For spring varieties, Polima restored hybrids and varietal associations have demonstrated a significative advantage compared to classical lines.