NEW YORK - Forbes.com readers, editors and a panel of experts rank the scythe as the sixth most important tool of all time, in terms of its impact on human civilization.

To modern eyes, the scythe may be best known from images of the Grim Reaper and Father Time—or as a weapon used by Buffy the Vampire Slayer. But this device was once one of the most important tools in the world, used to cut grass for hay and harvest crops from fields. It was essential for cereal agriculture, allowing a single worker to harvest several acres a day. And in peasant rebellions, scythes were often important weapons.

The scythe consists of a long wooden shaft, with handles on the end and in the middle, and a long curved blade on the other end. The blade is sharp on the inside of the curve, allowing the user to swing it through crops, cutting and gathering them at the same time.

The scythe’s smaller cousin, the sickle, dates back more than 5,000 years, and was initially made out of rock or baked clay. They took the form of small curved blades, held in the hand, and only allowed the user to harvest small patches of land each day.

By the 12th century, farmers in Europe had developed the longer, more ergonomic sickle, and used it to cut grass or weeds. In the 1500s, it became more commonly used for harvesting crops and remained the most popular tool for centuries.

In 1831, an Irish American farmer and inventor named Cyrus McCormick invented the mechanical reaper, which was drawn by a horse and made it possible to harvest as much grain in a day as a dozen men with scythes.

In the 20th century, scythes were replaced almost completely by machines, including the mower and combine. But they still find use in less developed countries, and there are even scythe enthusiasts and competitions throughout Europe and North America.

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Other important agricultural tools include the shovel, the hoe, the sickle, the cradle, the machete, the pitchfork.

Corporate Connections: Indiana-based Seymour Manufacturing has been making scythes since the late 1800s, and a wide variety of other hand-powered horticultural tools come from companies like A.M. Leonard, Ames True Temper, and Smith & Hawken, a division of Scott’s Miracle Gro (nyse: SMG - news - people ). Those of us looking to put a little less physical effort into our gardening can get electric mowers and trimmers from companies such as Troy-Bilt, Toro (nyse: TTC - news - people ) and Black and Decker (nyse: BDK - news - people ). Meanwhile, farmers no longer rely on workers with scythes to harvest their crops, instead they use massive combines from John Deere (nyse: DE - news - people ), Caterpillar (nyse: CAT - news - people ) and Kubota (nyse: KUB - news - people ).