REAPER

A reaper is a farm implement or person that (cuts and often also gathers) crops at harvest, when they are ripe. Usually the crop involved is a cereal grass. All mechanical reapers cut the grass; most also gather it, either by windrowing it or picking it up. Modern machines that not only cut and gather the grass but also thresh its seeds (the grain), winnow the grain, and deliver it to a truck or wagon it are called combine harvesters or simply combines; they are the engineering descendants of earlier reapers.

Hay is harvested somewhat differently from grain; in modern haymaking, the machine that cuts the grass is called a hay mower or, if integrated with a conditioner, a mower-conditioner. As a manual task, cutting of both grain and hay may be called reaping, involving scythes, sickles, and cradles, followed by differing downstream steps. Traditionally all such cutting could be called reaping, although a distinction between reaping of grain grasses and mowing of hay grasses has long existed; it was only after a decade of attempts at combined grain reaper/hay mower machines (1830s to 1840s) that designers of mechanical implements began resigning them to separate classes.

Mechanical reapers substantially changed agriculture from their appearance in the 1830s until the 1860s through 1880s, when they evolved into related machines, often called by different names (self-raking reaper, harvester, reaper-binder, grain binder, binder), that collected and bound the sheaves of grain with wire or twine. Today reapers and grain binders have been largely replaced by combines in commercial farming, but some smaller farms still use them.

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Wikipedia