EVOLUTION OF THE AREA CULTIVATED TO COMMON BEAN AND ECONOMIC IMPACT OF DROUGHT ON ITS YIELD UNDER RAINFED CONDITIONS IN MEXICO

Abstract

Common bean (Phaseolus vulgaris) is the second most important crop in Mexico after maize on planted area; however, according to official data, in the last decades the area and production have decreased, which may be related to climate variability, especially precipitation, in both the Spring-Summer and Fall-Winter production cycles. The objective of this study was to analyze the evolution of the rainfed area for production of common bean in Mexico and the relationship between drought and yield in the period 1980-2016. Based on information from the available databases for the crop, the evolution of the planted, harvested and damaged area, and seed yield was analyzed, and with climate information a drought index was calculated as the deviation of the precipitation with respect to the long term average (DP) for the period studied. Based on the DP, a dummy variable for drought classification was set in a 37- year database, for 21 states of Mexico in the Spring-Summer cycle and for 10 states in the Fall-Winter cycle. The DP and the dummy variable were analyzed using a fixed-effect econometric model. Regarding the evolution of the crop area, there was an increase in the damaged area and a decrease in both the area planted and yield. The estimated model for the Spring-Summer cycle was significant at P ≤ 0.05, with an R² of 0.55, which indicates that drought reduces yield by 53 kg ha^-1. The low adjustment of the models suggests that there are other factors, besides precipitation, that affect the production of rainfed beans in Mexico.