Significance of kernel moisture content in determination of Hagberg Falling Number in wheat

Abstract

The effect of early termination of kernel filling (early harvest) on the Hagberg Falling Number (HFN) was investigated over a four-year period. Selected South African wheat cultivars were harvested at different stages of kernel development, determined by kernel moisture content (KMC). HFN was determined at each stage of development. Difficulty in obtaining sufficient data points at each KMC necessitated the creation of two KMC ranges: 10–13.1% and 13.2–16.9%. Alpha-amylase activity was determined for each of the cultivars at the various KMCs during the 2003/04 and 2004/05 seasons. Data generated with three wheat cultivars (Elands, Gariep and Tugela-DN) over a four-year period indicated that the effect of KMC with harvest on the HFN of wheat is season dependant. Tugela-DN produced significantly (P≤0.05) higher HFN at the lower KMC range (10–13.1%) for two (2001/02 and 2004/05) of the four seasons during this study. Gariep showed similar results to Tugela-DN for the 2001/02 season. For Elands, the HFN remained constant over the four seasons at the various KMCs. Although there were no statistically significant differences between cultivars, it was observed that higher HFNs occurred at the lower KMC range. The effect of alpha-amylase activity at the KMC investigated in the study could not be successfully linked to reduced HFN measured at the higher KMC range. Late maturity alpha-amy-lase (LMA) was also excluded as a possible reason for reduced HFN. The current study indicated that some cultivars are prone to produce higher HFNs at lower KMCs but that the effect is limited to specific seasons.