Tannat is a vigorous grape variety, its natural yield easily close to 100 hectolitres per hectare. It is now understood that natural selection is not sufficient. Early on (in the 1980s), thanks to a handful of winemakers, Madiran became one of the first appellations in France to impose yield controls, as well as a good deal of work in the vineyard such as trellis training, leaf thinning and green harvesting in order to guarantee optimum grape maturity.
Also, the start of the harvest is subject to the publication of the official harvesting date, agreed upon by representatives of the winemakers and the INAO. The grapes can be picked mechanically but a large number of winemakers privilege hand picking, for qualitative and social reasons.