Hagberg Falling Number and Rheological Properties of Wheat Cultivars in Wet and Dry Preharvest Periods

Abstract

The effects of dry and wet preharvest periods on Hagberg falling number (HFN), a parameter of α-amylase activity, and rheological properties including farinograph dough development time (FDT), farinograph absorption (FA), resistance to extension (RE), loaf volume (LV) and baking score (BS) were examined in 30 hexaploid wheat (Triticum aestivum L.) cultivars originating from 19 countries. The cultivars were grown in the field in 2000–2010 and HFN and rheological properties were analyzed for three replicates. The cultivars were divided into three groups according to HFN in the wet preharvest period: HFN below 150 s (group H-1), HFN from 250 to 350 s (group H-2), and HFN over 400 s (group H-3). The cultivars in group H-3 were superior to those in either group H-1 or H-2 in all rheological properties except RE. In the dry preharvest periods, HFN was not correlated with rheological properties, while in the wet preharvest period HFN showed a highly significant positive correlation with FDT and BS. The canonical variate analysis for assessment of the general performance of all cultivars with HFN as the main factor and the other rheological properties as subfactors, indicated that the cultivars Stepnaja 30, Garazinko, Kirac, Klein Forten and Žitarka showed the highest potential regardless of preharvest rainfall amounts. In conclusion, differential genetic expression of resistance to preharvest sprouting, maintenance of low α amylase level, high HFN values, maintenance of rheological properties, and baking performance can be reliably detected and measured under wet preharvest conditions.