Since ancient times farmers have tried to improve their crops. They brushed pollen from one species on to another to combine desirable qualities.
In 1876 Charles Darwin discovered that inbreeding – pollinating with almost identical plants – made plants less vigorous. Cross-breeding between different strains produced healthier plants. Plants and people
In the early 1900s American scientists found that they could improve the protein content of corn by inbreeding – but the yield was poor.
In 1917 Donald Jones discovered the ‘double-cross, by combining four strains (not the normal two) to create a hybrid corn which gave high yield and high protein.
Hybrid corn changed US farming, raising yields from 2000 liters per hectare in 1933 to 7220 in 1980.
In the 1960s US farmers began growing wheat crosses such as Gaines, developed by Norman Borlaug from Japanese dwarf wheats.
Gaines and Nugaines are short-stemmed wheats that grow fast and give huge yields need masses of artificial fertilizers–but hey and pesticides.
In India and Asia new dwarf wheats and rices created a ‘Green Revolution, doubling yields in the 1960s and 1970s.
The Green Revolution means farmers now use ten times as much nitrogen fertilizer as they did in 1960.
The huge cost of special seeds, fertilizers and pesticides has often meant that only big agribusinesses can keep up, forcing some farmers out of business.
Many years ago, many farmers abandoned ts (Oft tonal wheat seeds (below right) and began planting big `superwheat’ seeds (top right.)