This is Steve Ember with the VOA Special English AgricultureReport.
Since ancient times, farmers have chosen the seeds for the comingyear from the biggest and best plants in their crop. The hope isthat these seeds will have the same good qualities as their parentplants. This method is called inbreeding. But experts say it is notthe best way to develop seed with strong, healthy qualities overtime.
In nineteen-oh-six, the genetic researcher G.H. Shull startedwork on breeding corn in New York State. He found that if he matedtwo inbred groups of corn plants, he could create a stronger newline of corn. This process is called crossbreeding. It produceshybrids from putting together different kinds of related plants.
Researchers soon recognized that they could crossbreed fourinbred lines of corn. The result is stronger than corn crossbredonly once. Hybrid corn first appeared in nineteen-twenty-one. Today,almost all corn planted in the United States is hybrid. And farmersharvest about seven times more corn from each hectare than they didseventy years ago.
Corn is not the only hybrid crop. Yuan Longping is called theFather of Hybrid Rice. He and other Chinese scientists worked onthis idea in the nineteen-sixties and seventies. The first hybridrice appeared in nineteen-seventy-four. Mister Yuan used three linesof parent seed that produced fifteen to twenty percent more grain.By nineteen-ninety-five, half of all the rice grown in China washybrid.
There are also hybrid animals. Long ago, farmers discovered thata female horse mated with a male donkey produces a mule. This animalis strong and good for work, although it cannot reproduce.
In the early nineteen-eighties, American fish farmers wanted toraise striped bass. This fish had almost disappeared from the wild.So researchers created a fast-growing hybrid bass. By two-thousand,fish farmers harvested almost seven-million kilograms of the newsunshine bass.
Hybrids are not the answer to every problem in agriculture. Newhybrid seeds must be bought each year. They also cost more thanother seed. Hybrids can take many years to develop. And not allcrops can be crossbred successfully. But hybrids have been animportant development for productivity.
This VOA Special English Agriculture Report was written by MarioRitter. This is Steve Ember.