196 / SEPTEMBER–OCTOBER 2017, VOL. 62, NO. 5 1 Corresponding author. Tel: +2758-3073439; Fax: +2758-3073518; E-mail: lindequerc@arc.agric.za http://dx.doi.org/10.1094/CFW-62-5-0196 ©2017 AACC International, Inc. Can Protein Quantity and Quality Predict the Breadmaking Quality of South African Wheat? R. Lindeque 1 Agricultural Research Council–Small Grain Bethlehem, South Africa M. Labuschagne and A. van Biljon University of the Free State Bloemfontein, South Africa T he climates of the primary wheat production regions of South Africa are diverse, and each requires specific produc- tion practices for sustainable wheat production (Fig. 1). In the irrigated wheat region (IRR), wheat is produced under center- pivot irrigators along the Oranje and Crocodile Rivers in the moderate to warmer northern areas of South Africa. Production consists of spring-type wheat varieties seeded at high densities, with a total of 280 kg of N ha –1 split between 160 kg of N at seeding, 60 kg of N between tillering and stem elongation, and 60 kg of N between flag leaf and anthesis. The central Free State Province produces the majority of dryland wheat in the summer rainfall region (Dryland SRR). Wheat produced in this region has strong rheological qualities (15) that are attributed to high tem- perature and rainfall conditions, which benefit winter- and inter- mediate-type wheat varieties with longer growth periods. Low seeding densities (25–30 kg ha –1 ) are applied with 60 kg of N ha –1 during seeding (2). The critical rainfall period affecting grain yield and quality in this region occurs shortly before anthesis (Fig. 2) (12). Dryland wheat production in the winter rainfall region (Dryland WRR), which has a Mediterranean-type cli- mate, occurs in the Rûens and Swartland regions of Western Cape Province. Spring-type wheat varieties are seeded with ≈130 kg of N ha –1 split between 100 kg of N during seeding and the remaining 30 kg of N applied between tillering and stem elongation (3). Complexities of the South African Wheat Industry Commercial Bread Baking. Commercial bread baking in South Africa has grown considerably since the 1960s with the advent of use of the Chorleywood bread process (CBP) stem- ming from the inclusion of South Africa in the British Common- wealth. The primary advantage of the CBP is the use of lower protein flours integrated with intensive, high-speed dough mix- ing, which reduces fermentation time and results in a flour-to- loaf rate of ≈3.5 hr. Weaker flours are generally less expensive, and protein content is not considered a primary factor in deter- mining the energy input level required for the CBP (5,6). With implementation of free-market principles in the South African wheat industry in the early 2000s, significant economic profits became possible for the commercial bread baking industry due to the availability of imported wheats that often had lower pro- tein contents. Unfortunately, this left the door wide open for wheat price manipulation, which has been detrimental to South Afri- can wheat producers and the wheat industry in general. Wheat Grain Yield and Flour Quality. A major misconcep- tion among wheat farmers globally is that grain yield is the sole factor responsible for long-term sustainability of wheat produc- tion. The reality is that grain yield is only one of several param- eters determining the price a farmer receives for a shipment of wheat delivered to a storage silo. In South Africa three primary parameters are used to determine the wheat grade after delivery: hectoliter mass (kg hL –1 ), protein content (%), and falling num- ber (sec). Protein content is an indicator of dough development time and water absorption of flour but frequently is a poor pre- dictor of baking quality. In a study on Swedish wheat, Fossati et al. (8) recommend selection of genotypes with lower protein con- Fig. 1. Rainfall patterns and primary wheat production regions in South Africa. Fig. 2. Dryland wheat production conditions in the northwestern Free State Province of South Africa.