Towards the end of the last century France produced up to 1000 tons of French black truffles from more than 20 French departments located primarily in the south east and south west of France. Since this period, output has fallen continuously, with some variation. During the period 1970-1980 production ranged between 30-60 tonnes. The causes for this great fall are many including; abandonment of land cultivation; wartime destruction of trees; planned de-forestation; acid rain.
In recent years total production of the French Truffle in France has been as low as 20 tonnes per year.
During the mid 1960s the French Government undertook a massive research program to try and save the industry. By the early 1970s a technique to artificially inoculate oak and hazelnut trees was developed. A private company using the technology under licence has produced and marketed several hundred thousand trees, resulting in a renewed interest in producing truffles. The technology has been successful with hazelnut trees producing truffles after 4 years and oaks producing after 6-8 years.
However, still as much as 75% of the truffles harvested come from the native oak and hazelnut forests, hence making annual production very much dependent on good spring and autumn rain.