Assessment of Intercropping and Plastic Mulch as Tools to Manage Heat Stress, Productivity and Quality of Jalapeño Pepper

Abstract

Under a global warming scenario, it is important to adopt practices that favor soil water conservation, such as plant intercropping systems and the use of plastic mulching. The objective of this study was to determine how microenvironment, morphology, productivity and quality of jalapeño peppers were affected by corn intercropping and the use of plastic mulching. Two experiments were conducted during 2015 and 2016 in the Valley of Mexicali, Mexico, a region characterized by its extreme aridity, soil salinity, hot temperatures and high radiation during the summer. Four treatments were tested: jalapeño peppers grown on bare soil (BS); on bare soil intercropped with corn (BS+IC); on plastic mulch (PMu); and on plastic mulch intercropped with corn (PMu+IC). The response variables measured were yield, fruit quality attributes, microclimatic variables, and morphology of the pepper crop. PMu treatment produced the tallest pepper plants and yields, while the BS+IC treatment produced the smallest plants and the lowest yields. A possible explanation for the higher biomass and crop yield of the PMu treatment is the lack of competition from corn and the effect of plastic mulching in reducing soil salinity. It is concluded that competition from corn on jalapeño pepper dramatically affected the pepper’s productivity, particularly under high soil salinity and extremely high temperature conditions.