Objective: To evaluate the yield of guajillo pepper (CHG) and chile de árbol pepper (CHA) grown in containers with coconut fiber substrate in a hydroponic greenhouse system.Methodology: Four types of chili peppers were tested: two CHG and two CHA peppers. The CHG peppers with seeds were from two growing areas in the state of San Luis Potosí (SLP), located in the Altiplano Central (high plateau region) of Mexico: one from Las Colonias, Salinas, and the other from El Barril, Villa de Ramos. The CHA pepperswere obtained in Yahualica, Jalisco: one in El Salto Verde (CHA-SaltoVerde) and the other in El Faro (CHA-Faro). The chili peppers were established in a hydroponic system with two types of containers (pots (SHM) and slabs (SHB)), in both of which coconut fiber (coir) was used as a substrate. The experimental design was completelyrandomized with three repetitions and the comparison of means was made with the Tukey test (p<0.05).Results: Significant differences were observed between chile de árbol and guajillo peppers grown in SHM regarding the following variables: plant height and number of leaves, flowers, and peppers. Chile de árbol peppers recorded the highest values for the four variables. There were also significant differences between the chile de árbol and the guajillo peppers regarding the fresh weight and dry weight variables, but, in this case, the guajillo peppers had the highest values. The highest dry weight value (g plant -1 ) was obtained by CHG-Barril (1,094 g plant -1 ), followed by CHG-Colonias (866 g plant -1); meanwhile, the lowest values were recorded for CHA-Faro and CHA-SaltoVerde chile de árbol peppers (819 and 258 g plant -1 , respectively). The same pattern was observed in the SHB, with significant differences between the chile de árbol —which had the highest values— and guajillo peppers for the following variables: plant height, number ofleaves, flowers, and peppers. There were also significant differences in terms of fresh weight between chile de árbol and guajillo peppers, with the latter recording higher values. Finally, CHG-Colonias and CHA-SaltoVerde showed the highest dry weight values with 633 and 595 g plant -1 , respectively. Although there were no significant differences between them, there were significant differences with respect to CHG-Barril and CHA-Faro (524 and 483 g plant -1 , respectively).Study Limitations/Implications: The present study has no major limitations.Conclusions: In general, a better dry yield of chili pepper was obtained with guajillo peppers produced in a pot system. Hydroponic systems in pots and slabs, using a coir substrate, are an alternative in protected agriculture for the production of guajillo and chile de árbol peppers.
