Six-month standardized precipitation indexes (SPI) along with degree-days indexes were calculated and maximum likelihood estimations were carried out for specific crops
using data spanning 1970 to 2000. The results show that while an increase in the degree-days tends to be harmful to crop yields, SPI and precipitation intensity index have statistically positive impacts on the mean crop yields. The adaptation to climate variability suggests a modernization of the farming techniques such as the reliance on irrigated agriculture.