An overview of the context and scope of wheat (Triticum aestivum) research in South Africa from 1983 to 2008

Abstract

The domestic requirement for wheat in South Africa is approximately 2.8 million tons and annually the shortfall on local production is imported to meet the demand. During the past 25 years two distinct wheat marketing mechanisms characterised the wheat industry, impacting significantly on both research and industry. In 1996 the single channel marketing system through the Wheat Board made way for a liberal marketing environment in which market forces of supply and demand determine price. This refocused most research activities on factors to lower input costs and risks, while increasing the profitability of wheat production. Significant challenges were experienced with much stricter milling and baking quality requirements impacting on not only the development of adapted wheat cultivars for South African conditions, but also on fertiliser and cultivar recommendations, as well as production practices. Minimum tillage, preharvest sprouting, as well as the threat of Russian wheat aphid and stripe rust were some of the pertinent challenges faced during this time. Significant scientific breakthroughs of international importance were made with regard to the physiological and biochemical nature of insect resistance and plant defence as well as the transfer of resistance genes from alien species. This review provides an overview of the most pertinent wheat research undertaken from 1983 to 2008.

Soil fertility constraints and yield gaps of irrigation wheat in South Africa

“…The samples were air dried (visible organic debris removed), ground (< 2 mm) and analysed at the ARC-SGI soil laboratory. The samples were analysed for electrical conductivity (EC; 1:1 soil to water suspension), pH (1:5 soil to 1 M KCl suspension), exchangeable acidity (1 M KCl), extractable P (Bray 1), exchangeable cations and extractable S (1 N NH 4 OAc at pH 7) and extractable Zn (0.1 M HCl) using procedures of the Non-affiliated Soil Analysis Working Committee. 23 In addition to these analyses, organic C (Walkley-Black method) 24 and particle size distribution (hydrometer and sieve method) 25 were also determined.…”

“…The yield potential of irrigation wheat in South Africa is increasing progressively because of improvements in the genetic yield potential of cultivars, pest and disease resistance as well as technological advancements that enable producers to improve crop management. 4 Hence, in recent years, researchers and industry agronomists conducting cultivar trials in South Africa have documented potential yields of up to 12 t/ha under controlled field experiments. 5 When these yields are compared with the national average yield of approximately 6 t/ha, it appears that there may be opportunity for improving wheat yield in some production areas of South Africa through refinements of crop and resource management strategies.…”

Identification of adult plant resistance to stripe rust in the wheat cultivar Cappelle-Desprez

“…Palmiet (pedigree: SST3*//Scout*5/Agent). Palmiet is a stripe rust susceptible spring wheat carrying the stem rust resistance genes Sr2 and Sr24, as well as the leaf rust resistance gene Lr24 (Smit et al 2010). Cappelle-Desprez 9 Palmiet F 2 seedlings were infected with spores of P. striiformis f. sp.…”

historical assessment of sources and uses of wheat varietal innovations in South Africa

“…Despite the first production of wheat in the 1600s, wheat varietal breeding was reported to have been established more than two centuries later in 1891. 5 The focus of wheat varietal improvements in South Africa addresses the following cultivar characteristics: adaptability to the production area, yield potential and stability, and agronomic characteristics (e.g. tolerance to diseases, pests and aluminium toxicity).…”

“…The wheat varietal improvement sector consists of three main actors: the Small Grain Institute of the Agricultural Research Council (ARC-SGI; established in 1976 as the then Small Grains Centre); Sensako, established in the mid-1960s (becoming autonomous in 1999 after functioning as part of Monsanto); and Pannar (entering the wheat breeding sector in the 1990s). 5 Periodic assessment of plant breeding is required to assess the benefits of ongoing investment to allow: (1) temporary constraints that could permanently hinder the identification of crop varietal improvements to be addressed; and (2) desirable characteristics -such as quality, quantity and environmental impact -to be identified and prioritised. 6 The main objective of this study was to undertake a historical assessment of the sources and uses of wheat varietal innovations in South African agriculture.…”