Potato late blight has long history Late blight of potato is currently a major problem in almost every potato growing region of the world. While scientist around the world look for new ways to control this plant disease and growers spend millions of dollars combating this problem, the history and the human impact of the disease is all but forgotten. This plant disease, which is probably totally unknown to most people, does have an interesting past and has played a role in human history.

The potato plant originated from South America in the mountains of southern Peru where the Incas used it as a food source as far back as 400 B.C. and is still a major food crop for the people in that region today. The Spaniards came across the potato in their quest for gold in South America sometime in the 16th century and brought it back with them to Europe. Initially Europeans used it as feed for livestock, and thought of it as unfit for humans.

Over time the Europeans learned that the potato was in fact a nutritious crop that could produce large amounts of food in just a small area of ground. In many parts of Europe it became the main food item, especially for the peasant farmers. Nowhere was this probably truer than in Ireland in the 1800s.

In the early 1800s Ireland was a major exporter of grains, meat, and dairy products to England. Peasant farmers used these cash crops to pay rent to the wealthy English and Irish absentee landowners. But to feed themselves, the Irish peasant farmers grew potatoes, which could yield large amounts of food on relatively small plots of land. Besides being a high yielding crop, potatoes are a very nutritious crop being high in carbohydrates, proteins, minerals, and vitamins.

In a typical day an Irishman may have eaten 8 to 14 pounds of potatoes and little else.

Genetically similar From 1800 to 1841 the population of Ireland grew from 4.5 million to over 8 million based on their agricultural export economy and the potato as their major food crop. By 1845 there were over 2 million acres of potatoes farmed in Ireland, mostly a genetically similar variety. Thus conditions were set for an impeding disaster; a very large population of people dependent on one crop with little genetic diversity.

The summer of 1845 was unusually warm and wet. Potato fields were soon infected by blight, causing the plants to rot in the field. Potatoes tubers that appeared sound were harvested but soon rotted in the cellars. The disease became epidemic not only in Ireland but most of Northern Europe and by the fall of 1845 it was apparent that widespread famine was going to occur.

Prime Minister Peel's government was slow to react to the situation in Ireland. Many died from starvation but many more died from typhoid fever, cholera, and dysentery. Eventually Peel's government repealed the Corns Laws, which prevented the importation of American maize.

The starving Irish were given cooked corn mash in open centralized kitchens, which the Irish soon called Peel's Brimstone.

Mechanical Transplanter Co. Late blight again returned in the following years. In 1847, the new government of Lord John Russell blamed the large landowners for the famine and demanded that they pay a tax to support the relief efforts. In response, the landowners simply increased the rent fees to the peasant farmers, which resulted in civil unrest.

By 1851 the population of Ireland had dropped from a high of 8.2 million to 6.5 million. At least one million died due to starvation and disease, while the rest had immigrated to English speaking areas of the world, mainly Canada and the U.S.

What have been some of the impacts of the Irish potato famine? Late blight was one of the first plant diseases to be demonstrated to be caused by a microorganism and thus put an end to the theory of spontaneous generation. The work at that time on late blight was also the beginning of a new science called plant pathology.

This disaster also demonstrates how plants that are adapted to one area may be out of place and susceptible to various problems if moved into new locations. And finally, it shows how extremely important it is to maintain genetic variability in the crops we raise and not have any one population rely too heavily on one strain of crop.

Seminars will be offered daily during the show. They will be held in the International Business Center, located in the new Heritage Complex on the grounds of the International Agri-Center.

The organizer of the annual seminar series is Fresno City College Export Center, University Center Export Program.

Following is the schedule for export seminars:

Tuesday Feb. 13:

10 a.m. Let's Talk Trade! Speakers: Candy Hansen and Jeanette Benson, Centers for International Trade Development; Eduardo Torres and Dale Wright, U.S. Department of Commerce, Export Assistance Centers; Josh Eddy, California

Department of Food and Agriculture.

11 a.m. Importing into the U.S. Speakers: Larry Dixon, Grundfos Pumps, and Dennis Byrnes, U.S. Customs.

Noon. Exporting Agricultural Equipment. Speaker: Wally Nefiodow, John Deere Co.

1 p.m. Developing New Markets. Speaker: Ralph Goldbeck, Carlin Manufacturing.

2 p.m. Venture Into E-Commerce. Speakers: Chris Nelson, TheAgZone.com, and Diane Friend, HorsePower.com.

3 p.m. Understanding Currency Exchange. Speaker: Wendy Webster, Wells Fargo Bank, Corporate Foreign Exchange.

Wednesday, Feb. 14:

10 a.m. Marketing Irrigation Equipment Internationally Speaker: Tim Kimmel, Irrigation Association.

11 a.m. Videoconference with Mexico and Canada. Presented by U.S. Embassies in Mexico and Canada.

1 p.m. How to be Successful At Trade Shows. Speaker: Eduardo Torres, U.S. Department of Commerce Export Assistance Center.

2 p.m. The Ten Commandments for Exporting in the Year 2001. Speaker: Dr. Bill Rice, CSU, Fresno.

3 p.m. Knowing Perishable Quality - The Internet Solution. Speaker: Dr. Patrick Brecht, PEB Commodities.

4 p.m. Doing Business in China. Speaker: John Riddering, Irriconsult.

Thursday, Feb. 15:

10 a.m. Videoconference with South Africa. Presented by the U.S. Embassy in South Africa.

11:30 a.m. How To Get Paid For Export Sales. Speakers: Steve Herrick, Sanwa Bank, and Tina Kong, Union Bank.

12:30 World Trends in Dairy Products. Speaker: Tom Suber, U.S. Dairy Export Council.