GROWING SEASON FOR MOISTURE AND TEMPERATURE AVAILABILITY, EVALUATED WITH THE THORNTHWAITE WATER BALANCE IN JALISCO, MEXICO

In Mexico, corn is the most important crop produced under rainfed conditions.In this condition, the planning of agricultural operations is highly dependent on rainfall, with lower yields and high risk of crop loss.In recent years, Mexico has been facing increasingly severe, frequent and intense droughts, with important impacts on all economic sectors, but with greater influence on agriculture and livestock.This is the reason that motivates the evaluation of water availability in the growing season (GS) of rainfed crops and to have a quantitative basis to propose management technologies to cushion its effects.The objective of the present work was to evaluate the GS due to the availability of adequate moisture and temperature for crops by means of the Thornthwaite model for Jalisco, Mexico.The study used the water balance model of Thornthwaite and Mather (1957).The characteristics of GS were obtained: onset, termination and duration, according to FAO criteria.The GS characteristics were mapped using interpolation procedure in IDRISI Selva and generating the final presentation in ARCVIEW GIS.The results show that the GS begins before June 10 in the central and western zones of the state; it continues with delays in the north of the state and the highlands of Jalisco until after June 30.The termination of the GS was irregular; it ended in the north and highlands of Jalisco before October 15; it continued in the rest of Jalisco until October 31.The duration of GS was shortest in the extreme north and highlands with less than 115 days, up to less than 160 days in the coast and south of Jalisco.