Influences of yearly weather variation and fertilizer rate on bread-makingquality in Swedish grown wheats containing HMW glutenin subunits 2+12 or 5+10 cultivated during the period 1990-96

The effects of weather and nitrogen application rate on bread volume, prote in concentration and gluten strength were investigated in spring and winter wheats in Sweden during 1990-96. The investigation was carried out in whea ts containing the high-molecular-weight (HMW) glutenin subunit combinations 2+12 or 5+10. The results showed that a warm (c. 20 degrees C mean dry temperature) and d ry grain-filling period, as during 1994 and 1995, led to high gluten streng th. As a relatively gentle dough mixing is normally applied in Sweden when baking bread, excessively high gluten strength results in low bread volumes . Wheat cultivars containing HMW glutenin subunits 5+10 generally had highe r gluten strength than those containing subunits 2+12. However, not all the cultivars containing subunits 5+10 showed overstrong gluten properties, wh ereas some cultivars containing subunits 2+12 were overstrong during 1994 a nd 1995. Different cultivars produced the highest gluten strength in differ ent years. Generally cultivars containing HMW subunits 2+12 gave higher bre ad volumes than those containing subunits 5+10. This is probably due to the Swedish baking method, where the dough is given a relatively gentle mixing for a fixed period of time. Increased fertilizer rates led to increased protein concentration and decre ased gluten strength. However, during certain years, for example 1994, the gluten strength was only decreased slightly by increased fertilizer rates, particularly in cultivars containing HMW glutenin subunits 5+10.