What is crop diversity?

Agriculture depends on relatively few crops – only about 150 are cultivated on any significant scale worldwide –
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However, each comes in a vast range of different forms.
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They may vary, for example, in height, flower colour, branching pattern, fruiting time, seed size, or flavour
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They may also vary in less obvious characteristics such as their response to cold, heat or drought, or their ability to tolerate specific pests and diseases.
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In fact it is possible to find variation in almost every conceivable trait, including cooking and nutritional qualities, and of course tasty
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And if a trait cannot be found in the crop itself, it can often be found in a wild relative of the crop.
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This multitude of different traits can be combined in an almost infinite number of ways.
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Diversity in a crop can result from different growing conditions: a crop growing in poor soil is likely to be shorter than a crop growing in fertile soil.
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It can also be the result of genetic differences: a crop may have genes conferring early maturity or disease resistance.
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It is these heritable traits that are of special interest as they are passed on from generation to generation and collectively determine a crop’s overall characteristics and future potential.
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Through combining genes for different traits in desired combinations, plant breeders are able to develop new crop varieties to meet specific conditions.
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A new variety might, for example, be higher yielding, more disease resistant and have a longer shelf life than the varieties from which it was bred.
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Put simply, crop diversity is the biological base of all agriculture.
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Its use goes back to the origins of farming, and farmers and scientists must continually draw on this irreplaceable resource to ensure productive harvests.
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World-watch