The Making of Our Daily Bread

Source: Food and Agriculture Organization of the United Nations, 2013, Cary Fowler, Charlotte Lusty and Maria Vinje Dodson, and Global Crop Diversity Trust, "The Youth Guide to Biodiversity" 1st Edition (Chapter 3) Youth and United Nations Global Alliance. Reproduced with permission.

Chapter 3. Verbatim.

In the 1940s, farmers were losing much of their wheat crop to a fungus known as stem rust. The fungal spores are carried by the wind from field to field. The spores can land on any part of the wheat plant and infect it, forming pustules on the stem and leaves, and causing the plant to produce much less seed, if not to die altogether.

Breeders screened wheat genebanks – storehouses of genetic diversity – for plants that do not appear to get the symptoms of the disease when grown in the presence of the fungal spores. They crossed popular wheat varieties that die from stem rust with the wild relatives that seem to resist the disease to breed new forms of disease-resistant wheat that produce good yields. The new varieties were taken up enthusiastically by farmers, and spread worldwide. One of the scientists responsible, Norman Borlaug, went on to win a Nobel Prize for his efforts. There is probably not one single reader of this book who has not benefited from Norman Borlaug’s work. 

In 1999, a new stem rust appeared in Uganda and spread into the Middle East. Plant breeders are screening all their genetic resources once more to find wheat varieties with resistance to the new disease. It is important to realise that a new devastating disease in a major crop is not news – this is business as usual in the world of agriculture! So it’s important to keep a large genetic diversity to be ableto produce new varieties which are resistant to these new diseases.