CULTIVAR AND CROP MANAGEMENT EFFECTS ON TEST WEIGHT IN WINTER WHEAT (Triticum aestivum)

Test weight or volumetric (hectolitre) weight is an important trait of wheat grain, being an important predictor of flour extraction rate and a determinant factor of the efficiency of wheat transport and storage. It is included in most standards for cereal grading and as such can influence the price received by farmers. Test weight was measured in yield trials with winter wheat cultivars grown with several crop management practices at the National Agricultural Research and Development Institute Fundulea - Romania (44 degrees 27'45'' N latitude and 26 degrees 31'35" E longitude, 68 m above sea level) in three seasons. Years were the main factor of test weight variation and this was associated with differences between years in maximum temperatures during the second half of grain filling period. Cultivars also had a very significant effect, while the influence of mangements and of interaction between cultivars and managements with years was not significant. On average most cultivars fulfilled the requirements for Grade 1 and 2, but the percentage of cases below the 75 kg hl-1 limit varied from 0 to 66.7%. Only two of the Romanian cultivars had half or more cases in Grade 3, while most Western European cultivars had more than 50% samples below 75% kg hl-1. Variances of the test weight values suggest that cultivars are different in stability of test weight, with most of the Romanian cultivars being less affected by the weather conditions than most Western European varieties. Two of the shortest Romanian cultivars (Voinic and Izvor) had highest average test weight and lowest frequency of lower grades, which is a progress but at the same time suggesting large possibilities of improving this trait in semidwarf wheat.