Durum wheat is grown globally on 13.5 million ha in 2020/2021, which amounts to 6.2% of the wheat area. It is assumed that in the past it was more important, but the extent of that importance is unknown. In this work, a historical estimation of the durum wheat area globally was carried out, based on data of the main cultivating countries. Many of the data from the earliest period were based on percentage to all wheat. During the nineteenth century, the percentage of durum wheat to all wheat globally was around 14–16%. However, throughout the 19th and beginning of the 20th century, in America (USA, Canada, Argentina), Asia (Russia, China, India), and Australia, new land was sown with bread wheat, and therefore the percentage of durum wheat fell steadily to 7–9% from 1950 to 2005, and to 6–7% since then. For many years, Russia was the country with more durum wheat cultivation, with around six million ha in the period 1910–1940. Turkey, Italy, Algeria, and India were also big historical players regarding cultivation of this crop. Currently, Canada, Algeria, Italy, and Turkey have the largest durum wheat acreage. The main breeding activities and the future of durum wheat are discussed.

Components of resistance conferred by the Lr46 gene, reported as causing “slow rusting” resistance to leaf rust in wheat, were studied and compared with the effects of Lr34 and genes for quantitative resistance in cv. Akabozu. Lr34 is a gene that confers non‐hypersensitive type of resistance. The effect of Lr46 resembles that of Lr34 and other wheats reported with partial resistance. At macroscopic level, Lr46 produced a longer latency period than observed on the susceptible recurrent parent Lalbahadur, and a reduction of the infection frequency not associated with hypersensitivity. Microscopically, Lr46 increased the percentage of early aborted infection units not associated with host cell necrosis and decreased the colony size. The effect of Lr46 is comparable to that of Lr34 in adult plant stage, but in seedling stage its effect is weaker than that of Lr34.

Agronomy for Sustainable Development, An International Journal in Agriculture and Environment