Hemp growers and entrepreneurs who were joyous a year ago after U.S. lawmakers reclassified the plant as a legal agricultural crop now are worried their businesses could be crippled if federal policymakers move ahead with draft regulations. Growers are concerned the government wants to use a heavy hand that could result in many crops failing required tests and being destroyed. The U.S. Department of Agriculture, the agency writing the rules, estimates 20% of hemp lots would fail under the proposed regulations.