Whenever I eat an ear of sweet summer corn on the cob (so good in the markets just now, piled up in its green husks), I think of William Cobbett, that great Tory radical of the early 19th century. Cobbett was a man who loved corn as much as he hated injustice. One of those figures as famous during his lifetime as he has been subsequently neglected, Cobbett should be remembered not least as an important champion of sweet corn, or Indian corn as it was then known, "a very delicious thing in its half-ripe or milky state".

William Cobbett (1763-1835) was a man of strong feeling. When he took up a cause - against capitalism, drunkenness, the French revolution, or the English education system or in favour of the labourer and the yeoman farmer - he did so with all his blood and girth.

Politically, he was inconsistent: first a Tory, then a quasi-Whig and finally a radical. But, as his biographer Daniel Green puts it, "there was never a time when he was not, in the truest sense of the word, an Independent".

Cobbett's love of "Indian corn" was first evident on Long Island, where he spent a year farming from 1817-18, as recorded in A Year's Residence in the United States. Here, he observed, these buttery yellow heads - practically unknown in England - were "eaten by man and beast in the various shapes of whole corn, meal, cracked and every other way that can be imagined".

Cobbett fed his horses with "Indian corn" and became convinced that this corn diet was what made them grow so strong and fast. As for himself, he relished fresh ears of corn as one of the luxuries - along with bacon and easy hospitality - of this Land of Plenty.

If only corn could be made to grow in England, thought Cobbett, it could drive out the "accursed, soul-destroying" potato as a staple food. (Potatoes were one of his worst betes noires. Cobbett believed that, as well as being less nutritious than bread, they forced workers' wives into a life of boiling and drudgery. Walter Raleigh, he insisted, was "one of the greatest villains upon earth".) The trouble was that England was too cold for frost-sensitive corn to ripen.

For a while, therefore, Cobbett abandoned corn cobs in favour of other agricultural crazes. But then in 1826, one of his sons brought him a dwarf strain of Indian corn that he had found growing in the garden of a Frenchman. At once, Cobbett set to work and planted the seed in his Kensington nursery, where, excitingly, it did ripen.

Next, he dashed off A Treatise on Cobbett's Corn, a rambling eulogy to this glorious crop. The book was even printed on paper made from corn husks. England, he argued, could be "the richest agricultural country in the world", if only it would grow corn. To that end, Cobbett marketed and sold the seed to farmers as "Cobbett's corn", and for a long time, this was what maize was called.

Alas, like many of Cobbett's ventures, Cobbett's corn looked better on paper than in practice. When grown on a farm scale rather than in a sunny Kensington garden, the particular dwarf hybrid of Cobbett's corn failed to ripen. The dream of an England made rich on corn evaporated.

Often in his long life, Cobbett was wrong. Shakespeare, he believed, was a mediocrity. He could also be grotesquely xenophobic and anti-Semitic. About corn, though, he was not mistaken. While Cobbett's corn was a flop, corn on the cob is still one of the sunniest pleasures of summer. Munching on the wholesome kernels, you can almost believe you are one of Cobbett's beloved yeoman farmers.