Water restriction during the vegetative and reproductive stages of Capsicum annuum var. glabriusculum, and its effect on growth, secondary metabolites and fruit yield

Abstract

Abstract The fruits of Capsicum annuum var. glabriusculum, due to their culinary use, have a high market demand in southeastern Mexico. The obtained product is the result of the abiotic and biotic conditions that this species faces during its development and production under wild conditions because its cultivation has not yet been established. To advance the knowledge of the response of this chili to abiotic factors, the growth, secondary metabolite concentrations and yields of plants subjected to water deficit (WD) were evaluated during two phenological stages: vegetative and reproductive (flowering and fruiting). Two independent experiments were established, each under a completely randomized design with a 2 × 4 factorial arrangement. The treatments were a) with and without WD during the vegetative stage (VS) and b) with and without WD during the reproductive stage (RS). Each treatment comprised groups of 20 plants and had four sampling dates. The results showed that the application of WD during the VS affected the growth, accumulation of biomass, leaf area, and duration of the phenological stages of this species. During the VS, WD decreased the number and weight of plant−1 fruits (60.9 and 59.4 %, respectively) compared to the treatment without WD. In both stages, the proline content in leaves increased (93.9–100%) with WD. The concentrations of photosynthetic pigments, phenolic compounds and total flavonoids in leaves and the contents of capsaicin and dihydrocapsaicin in fruits were not affected by WD in either the VS or RS. In general, this species is more sensitive to WD applied during the VS than the RS.