DisplayTitle

Effect of Glyphosate Application on Hagberg Falling Number of Wheat

¹Agricultural Research Council, Small Grain Institute, Private Bag X29, Bethlehem, 9700, South Africa. ²Agricultural Research Council, Grain Crops Institute, Private Bag X1251, Potchefstroom, 2520, South Africa. ³Corresponding author. Phone: (018) 299 6100 (Int: +2718) Fax: (018) 294 7146 (Int: +2718). E-mail: cravenm@arc.agric.za ⁴University of the Free State, Dept. Plant Sciences. Bloemfontein, 9300, South Africa.

A study was conducted to investigate management of Hagberg Falling Number (HFN) by creating more homogenous wheat through glyphosate applications at soft and hard dough stages individually, without compromising wheat quality. The effect of the treatments varied over cultivars and seasons. Thousand kernel mass (2003/04), hectolitre mass (2003/04 and 2004/05), and protein content (2003/04 and 2004/05) were negatively affected by soft dough stage treatments for all three cultivars included in the study. Days to harvest and growing degree days were significantly reduced with the soft dough treatment. Yield and preharvest sprouting were not affected. α-Amylase activity varied over season, cultivar, and treatment. HFN measured for Tugela-DN treated at soft dough stage produced a significantly higher HFN compared with the control (2004/05). None of the other cultivars at the various treatments indicated any HFN response to glyphosate application. Germination was severely affected by soft dough stage glyphosate application in the first year of evaluation. Studies into the effect of the various treatments on the repeatability of the HFN test, indicated that glyphosate treatment managed to produce a certain amount of stability for two of the three cultivars, but the treatment that resulted in the stability varied between seasons.