Optimal and marginal thermal regions for the cultivation of agave tequilana on the Jalisco State [Regiones térmicas óptimas y marginales para el cultivo de agave tequilana en el Estado de Jalisco]

Because of the increase of the demand for the beverage known as tequila, agave azul (Agave tequilana Weber) has become an important crop for the State of Jalisco. Notwithstanding this demand, cultivation areas have been reduced during the last four years, because of the damage caused by pests and diseases. Recently, new plantations have been established in different localities of Jalisco. Some of these new localities, however, have climatic conditions that differ from the traditional sites of cultivation. With the purpose of directing the future cultivation of Agave tequilana, an examination of the photosynthetic response to seasonal changes was realized in plantations in Amatitan and Arandas, Jalisco. These plantations are located in two of the most important cultivation regions for A. tequilana. The Amatitan and Arandas plantations have different average annual temperatures, since they are located at altitudes of 1000 m and 2000 m. Photosynthesis increased with fresh average diurnal temperatures (22-25 °C) and fresh night temperatures (14-16 °C), but decreased with warm temperatures during the day (>28 °C) and night (>20 °C). Photosynthetic response to temperature was used to define the thermal stratification ranges that include average annual nocturnal and diurnal temperature. The probability of temperatures less or equal than -7 °C occurring in Jalisco was also determined. Thermal ranges were used to identify regions with reduced risks caused by low temperatures, and regions with temperatures favorable for photosynthesis for A. tequilana. A map of Jalisco was developed, in which the optimal and marginal areas for the cultivation of A. tequilana were identified. The optimal thermal areas for the cultivation of A. tequilana are located in the north, northeast and central parts of Jalisco, the marginal areas in the region called Los Altos, the coastal plains, and inland canyons