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Plants have a “biological clock” that tells them when to grow leaves and produce seeds. Understanding that clock may help scientists develop crops to feed a growing population in an increasingly warmer world. Experts have said the expected growth in the production of major food crops would not be enough to support the human population by 2050. Rob McClung is a biologist at Dartmouth College in the United States. He says scientists need to create ways to feed the almost 10 billion people expected by the middle of the 21st century. He says estimates show that the world’s food supply will have to increase by about 50 to 60 percent over the next 35 years. To find new ways to increase productivity, Mr. McClung studied the biological clocks of plants. He found that different genes in plants affect the clock. His findings were published in the Proceedings of the National Academy of Sciences. Rob McClung says he identified a gene called GIGANTEA in a common species of field mustard. The plant is related to turnips and other vegetables. The gene speeds up or slows down the rate of development in the plant. That influences genetic traits like resistance to extreme cold and high salt. Mr. McClung says the hope is to give researchers a molecular tool to produce more crops. He says they might use this information to make a crop that can accept a higher level of salt or grow in a colder climate. Mr. McClung hopes that by working with the plant clock, researchers will be able to develop plants that perform more effectively.