The Hart-Parr Model 3 tractor was a commercial success, prompting no less a businessman than Henry Ford to get into the picture. In 1917 he introduced the Fordson, weighing as little as one ton and advertised to sell for as little as $395. The Fordson soon ruled the tractor roost, accounting for 75 percent of the U.S. market share and 50 percent of the worldwide share. Nevertheless, the tractor business remained a competitive field, at least for a few decades, and competition helped foster innovations. Tractors themselves got smaller and more lightweight and were designed with a higher ground clearance, making them capable of such relatively refined tasks as hauling cultivating implements through a standing crop. Another early innovation, introduced by International Harvester in 1922, was the so-called power takeoff. This device consisted of a metal shaft that transmitted the engine power directly to a towed implement such as a reaper through a universal joint or similar mechanism; in other words, the implement "took off" power from the tractor engine. The John Deere Company followed in 1927 with a power lift that raised and lowered hitched implements at the end of each row—a time- and labor-saving breakthrough. Rubber tires designed for agricultural use came along in 1933, making it much easier for tractors to function even on the roughest, muddiest ground. And ever mindful of the power plant, engineers in the 1930s came up with diesel engines, which provided more power at a lower cost. As tractor sales continued to climb—peaking in 1951, when some 800,000 tractors were sold in the United States—equally important developments were occurring on the other side of the hitch. Pulled and powered by tractors, an increasingly wide variety of farm implements were mechanizing just about every step in the crop-growing process, from the planting of seed to the harvesting of the final fruit. In the 1930s one particular type of machine—the combine—began to take its place beside the tractor as a must-have, especially for grain farmers. The combine had been a bold innovation when Hiram Moore developed the first marketable one in the 1830s. As its name indicated, it combined the two main tasks of grain harvesting: reaping, or cutting the stalks, and threshing, the process of separating the kernels of grain from the rest of the plant and then collecting the kernels. Early combines were pulled by large teams of horses and proved about as unwieldy as the first steam-powered tractors. But towed by the powerful new diesel tractors of the 1930s and taking their power off the tractors' engines, combines became the rage. They did it all: cutting, threshing, separating kernels from husks with blowers or vibrating sieves, filtering out straw, feeding the collected grain via conveyor belts to wagons or trucks driven alongside. This moving assembly line turned acre upon acre of waving amber fields into golden mountains of grain as if by magic.
The first self-propelled combine was developed in Australia in 1938, incorporating tractor and harvester in one, and improvements have been steady ever since. Today, the most impressive of these grain-handling machines can cut swaths more than 30 feet wide, track their own movements precisely through Global Positioning System satellites, and measure and analyze the harvest as they go. They are in no small measure responsible for a 600-fold increase in grain harvesting productivity. The first self-propelled combine was developed in Australia in 1938, incorporating tractor and harvester in one, and improvements have been steady ever since. Today, the most impressive of these grain-handling machines can cut swaths more than 30 feet wide, track their own movements precisely through Global Positioning System satellites, and measure and analyze the harvest as they go. They are in no small measure responsible for a 600-fold increase in grain harvesting productivity. The same basic combine design worked for all grain crops, but corn required a different approach. In 1900 corn was shucked by hand, the ears were thrown into a wagon, and the kernels were shelled by a mechanical device powered by horses. The first mechanical corn picker was introduced in 1909, and by the 1920s one- and two-row pickers powered by tractor engines were becoming popular. Massey-Harris brought the first self-propelled picker to the market in 1946, but the big breakthrough came in 1954, when a corn head attachment for combines became available, making it possible to shell corn in the field. The increase in productivity was dramatic. In 1900 one person could shuck about 100 bushels a day. By the end of the century, combines with eight-row heads could shuck and shell 100 bushels in less than 5 minutes! The hay harvest also benefited from mechanization. In the 1930s mechanical hay balers were at work, but the process still required hand tying of the bales. In 1938 a man named Edwin Nolt invented a machine that automated bale tying, and the New Holland Manufacturing Company incorporated it into a pickup baler that it began marketing in 1941. As in the case of the combine, self-propelled versions soon followed. Soon just about anything could be harvested mechanically. Pecans and other nuts are now gathered by machines that grab the trees and shake them, a method that also works for fruits such as cherries, oranges, lemons, and limes. Even tomatoes and grapes, which require delicate handling to avoid bruising, can be harvested mechanically, as can a diverse assortment of vegetables such as asparagus, radishes, cabbages, cucumbers, and peas.
Mechanical engineering ingenuity found solutions for even more problematic crops—the worst of which was probably cotton. In the long history of cotton's cultivation, no one had come up with a better way to harvest this scraggly tenacious plant than the labor-intensive process of plucking it by hand. The cotton gin, invented in 1794 by Eli Whitney, mechanized the post-harvest process of extracting the cotton fibers from the seedpod, or boll, but no really successful efforts at mechanizing the picking of cotton occurred until the 1930s. In that decade, brothers John and Mack Rust of Texas demonstrated several different versions of a spindle picker, a device consisting of moistened rotating spindles that grabbed the cotton fibers from open bolls, leaving the rest of the plant intact; the fibers were then blown into hoppers. Spindle pickers produced cotton that was as clean as or cleaner than handpicked cotton; soon they replaced earlier stripper pickers, which stripped opened and unopened bolls alike, leaving a lot of trash in with the fibers. The Rust brothers' designs had one shortcoming: They couldn't be mass produced on an assembly line. Thus credit goes to International Harvester for developing the first commercially viable spindle picker in 1943, known affectionately as Old Red.
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