the ground. In the 1950s a new system known as parral cuyano was introduced where vines were trained high off the ground with the clusters allowed to hang down. This style was conducive to the high yielding varieties of Criolla and Cereza that were the backbone of the bulk wine production industry that arose in response to the large domestic market. In the late 20th century, as the market turned to focus more on premium wine production, more producers switched back to the traditional espaldera system and began to practice canopy management in order to control yields. Irrigation The intricate irrigation system used to bring water from melted snow caps in the Andes originated in the 16th century (with the Spanish settlers adopting techniques previously used by the Incas) and has been a vital component of agriculture in Argentina. Water flows down from the mountain through a series of ditches and canals where it is stored in reservoirs for use by vineyards which can apply for government-regulated water licenses that grant them access to the water. Newly planted vineyards on land that does not have existing water rights will often use alternative water sources such as drilling deep boreholes to below the surface to retrieve water from underground aquifer. These water wells, though costly to build, can supply a vineyard with as much as of water per hour. Historically, flood irrigation was the most common method used, whereby large amounts of water are allowed to run across flat vineyard lands. While this method may have been an unwittingly preventive measure against the advance of phylloxera, it does not provide much control for the vineyard manager to limit yields and increase potential quality in the wine grapes. Subsequently, a method of furrow irrigation was developed whereby water is funneled into furrow channels that the vines are planted in. While providing a little more control, this method was still more suited to producing high yields. In the late 1990s, drip irrigation started to become more popular. Though expensive to install, this method provides for the maximum level of control by the vineyard manager to facilitate yield control and increase potential quality in the grape by leveraging water stress on the vine. Wine regions While there is some wine production in the provinces of Buenos Aires, Córdoba and La Pampa, the vast majority of wine production takes place in the far western expanse