Prohexadione-Ca Modifies Canopy, Antioxidant Levels and Enzymatic Activity on Jalapeño Pepper Grown in Greenhouse

Aims: The use of growth retardants may be an alternative to improve yield and fruit quality of jalapeño pepper (Capsicum annum L.) growing in greenhouse; particularly when a high antioxidants fruit content is the main goal. Prohexadione calcium (P-Ca) is a bioregulator which reduces vegetative growth and increases antioxidants content in deciduous fruit species. The effect of P-Ca in jalapeño pepper is little known, therefore, the objective of this study was to evaluate the effect of P-Ca on the phenotype and fruit quality nutraceutical on jalapeño pepper hybrid Grande.

Study Design: A Completely Randomised Block Design was used, with four replicates per treatment. The results obtained were analyzed with the statistical program SAS (2009), for Windows version 9.1, and for the analysis of variance and comparison of means, the Tukey (P≤0.05) test was applied.
Place and Duration of Study: The experiment was established at the Universidad Autonoma Agraria Antonio Narro in Saltillo, Coahuila, Mexico, between April and July 2012.
Methodology: When seedlings had reached to 10 true leaves, a first foliar application and 15 days later, a second application of P-Ca at 0, 100, 200 and 300 mg L-1 were conducted.
Results: Application of Prohexadione-Ca reduced the final height and diameter of main stem; as well as yield. The P-Ca caused ripen fruits with significantly increase in the content of capsaicin, total carotenoids, vitamin C and catalase and peroxidase activity. Improvement in fruit quality compensates yield reduction since the benefit:cost (B:C) ratio in P-Ca fruits had a value of 0.46 as a result of a higher market price, whereas in control samples was 0.27.
Conclusion: Prohexadione-Ca has a potential to improve fruit quality in jalapeño pepper hybrid Grande growing under greenhouse conditions.