Physiological and Productivity Responses in Two Chili Pepper Morphotypes (Capsicum annuum L.) under Different Soil Moisture Contents

Abstract

The aim of this study was to explore some physiological and productivity responses of two chili pepper morphotypes (Capsicum annum L.) exposed to different soil moisture contents. A randomized block design in a split-plot arrangement with four replicates was used. The large plots (32 m long and 3.2 m width) were 25% ± 2 as the optimum soil moisture content (OSMC), and 20% ± 2 as the suboptimum soil moisture content (SSMC); the small plots (16 m long and 3.2 m width) were two chili pepper morphotypes: Jalapeño and Chilaca, respectively. Jalapeño plants showed more stability in relative water content (RWC), photosynthetic activity (µmol CO2/m2/s), and a relatively low transpiration (mmol H2O/m2/s) and stomatal conductance (µmol H2O/m2/s); therefore, it had a higher number of flowers per plant and number of fruits per plant, consequently recording a high fruit production of 3.94 and 2.99 kg/m2 in OSMC and SSMC, respectively. In contrast, the Chilaca chili showed low stability in water relative content (WRC), photosynthesis, and transpiration, going from OSMC to SSMC, as well as showed a lower yield in SSMC; however, all of that was compensated by its size and weight of the fruit per plant, with a yield of 4.95 kg/m2 in OSMC. Therefore, the Jalapeño chili pepper could be an option when the irrigation water is limited, and the Chilaca chili pepper when this resource is not limited.