Berkeley, Reverend M. J. (1803-1889)

British cleric and fungal researcher and classifier

M.J. Berkeley lived in Britain during the nineteenth century. An ordained minister, he is best known for his contributions to the study and classification of fungi . He compiled a number of volumes of literature on fungi. One of the best-known examples is the massive and well-illustrated Outlines of British Fungology, which was published in 1860. In this volume, Berkeley detailed a thousand species of fungi then known to be native to the British Isles. He was involved active in chronicling the discoveries of others. As examples, he co-authored a paper that described the findings of a United States–Japan expedition that found many species of fungi in the North Pacific in 1852–1853, and wrote several treatises on botanic expeditions to New Zealand and Antarctica.

Another of Berkeley's important contributions were connected to the Irish potato famine. From 1846 to 1851, the loss of the potato crops in Ireland resulted in the death due to starvation of at least one million people, and the mass emigration of people to countries including the United States and Canada. The famine was attributed to many sources, many of which had no basis in scientific reason. Dr. C. Montane, a physician in the army of Napoleon, first described the presence of fungus on potatoes after a prolonged period of rain. He shared this information with Berkeley, who surmised that the fungus was the cause of the disease. Berkeley was alone in this view. Indeed, Dr. John Lindley, a botany professor at University College in London, and a professional rival of Berkeley's, hotly and publicly disputed the idea. Lindley blamed the famine on the damp weather of Ireland. Their differing opinions were published in The Gardener's Chronicles.

With time, Berkeley's view was proven to be correct. A committee formed to arbitrate the debate sided with Berkeley. On the basis of the decision, farmers were advised to store their crop in well-ventilated pits, which aided against fungal growth.

The discovery that the fungus Phytophthora infestans was the basis of the potato blight represented the first disease known to be caused by a microorganism, and marked the beginning of the scientific discipline of plant pathology.

Berkeley also contributed to the battle against poultry mildew, a fungal disease that produced rotting of vines. The disease could e devastating. For example, the appearance of poultry mildew in Madeira in the 1850s destroyed the local wine-based economy, which led to widespread starvation and emigration. Berkeley was one of those who helped established the cause of the infestation.