This factsheet aims to highlight the interannual variation of the pine cone dimensions and present some factors that explain it, in order to contribute for the future establishment of silvicultural measures than can lead to a decrease in that variation, by promoting the conditions for bigger pine cones or selecting more suitable Forest Reproduction Materials (FRM) .
The environmental factors that play a role in the fructification of black truffle are well known. In particular, low water availability during summer period inhibits fruiting. These elements result from observations and tests under controlled conditions. At the time of the study (late 1970s), there was no field trial to determine experimentally the influence of environmental factors in cultivated truffle conditions. A trial on a truffle farm located in south-eastern France was therefore set up in 1979 to clarify the influence of soil fertility and moisture levels on Black truffle...