Effect of Irrigation Frequency and Shade Levels on Vegetative Growth, Yield, and Fruit Quality of Piquin Pepper (Capsicum annuum L. var. glabriusculum)

Abstract

In Mexico, piquin peppers are highly valued horticultural products with limited cultivated production due to low seed germination, morphologic and genetic variability, disease susceptibility, and limited environmental physiology information. The objective of this study was to evaluate the effects of irrigation frequency and shade level treatments on vegetative growth, yield, and fruit quality of a commercial ecotype of piquin pepper. The study was conducted during two consecutive years using a hierarchical linear mixed-effects model design, with yearly data of irrigation frequency as main treatment blocks and shade levels as secondary blocks (nested within irrigation frequency treatments). Our results indicate that more frequent irrigation and increased shade levels favored vegetative growth. In addition, moderate shade levels (interception of 35% of full sunlight) and daily irrigation provided the best conditions for fruit production. This effect could be attributed to an increase in vegetative growth (thus higher photosynthetic and crop load capacity); more moderate conditions (temperatures and relative humidity) that favored flowering and fruit set, or a combination of these factors. Fruit size and pungency were not significantly affected by the treatments. Our results provide basic information for the development of guidelines for the cultivation of piquin pepper plants.