The harvesting of walnuts is held every year between the months of September and November. It is done when the husk will crack and that the hull is dark and damp. Walnut trees are then shaken to fall the ground walnuts and then they are picked up and washed before be dried, except of course for fresh walnuts.
For the walnuts of Grenoble PDOthe date of harvesting is determined by a commission of maturity made up of traders, directors, producers, and members of the CING, the INAO, the SENURA, and is formalized in a prefectoral Decree. The walnuts are harvested good mature i.e. when the kernel is solid and peels easily. The internal central partition is completely brown for 80% of the concerned Orchard walnuts. The drying starts as soon as possible and maximum within 36 hours after harvest.
Coopenoix and its Member producers collect annually on average 6,000 tonnes of wanuts, from which, about 250 tonnes are fresh walnuts.
A bit of history...
As early as 1927, members of the Federation of producers of walnuts shake the branches with a pole picker, collect walnuts by hand, wash and sort carefully before making a first calibration to the dimensions specified by the board of directors of the Federation. Most often, walnuts are gathered by the communal Federation that book cart pulled by oxen or "motor truck" and delivered them to the Federation whose headquarters is located in the Albenc. Upon their arrival, the bags are weighed in front of a Union delegate and a member of the Board of Directors. The Federation rule in cash the Union representatives who pay money to farmers in their area. This practice will continue until the 1960s where cheques replace cash. It was only in the 1970s that producers are paid directly and individually forcing many of them to open a bank account for the first time.
In 1929, the walnuts are delivered to Tullins factory. Profesional workers remove walnuts of bad appearance. Walnuts then go in mechanical washers and then in the dryer before be calibrated mechanically. They are then put into bags, from 50 kg to 500 g, before being shipped.
In 1932, 900 tons of walnuts are harvested from which 625 tons are sold in shells, 75 tons in fresh walnuts and 200 tons in kernels.
The highest harvests are recorded in 1952, 1972, 1982, and 2006. Between 1990 and 2000, production is increased from 1 600 to 3 300 tonnes.
In 2008, COOPENOIX collects 6 000 tonnes of which 250 tons of fresh walnuts, 5,900 tonnes of dry walnuts, 150 tons of kernels.
Apart from the fact that the sector of crop (from Saint Marcellin to Moirans in 1936) expanded and extends today from the Drôme to the Savoy, the regular increase of the production is also explained by the fertilization, the quality of treatments and the pruning of the walnut trees.
In 1924, we planted 40 to 60 walnut trees per hectare and trees produced walnuts only after fifteen years. Today, a one-hectare orchard has more than a hundred trees which produce walnuts after five years. Since 1980, the harvest is completely mechanized.