Morphological response and fruit yield of sweet pepper (Capsicum annuum L.) grafted onto different commercial rootstocks

Abstract

In attempts to phase out the use of methyl bromide as a fumigant, the grafting of sweet pepper may be used in integrated disease management to produce the fruit safely in an environmentally friendly way; however, there has been controversy as to whether the use of the graft affects the fruit yield. Therefore, the aim of this study was to evaluate the morphological characteristics and yield of marketable fruit of the pepper cultivar Triple Star grafted onto eight rootstocks. Ninety percent of the variability in the agronomic and morphological characteristics of non-grafted and grafted Triple Star individuals was explained by the first three canonical roots, in which discriminating characteristics of weekly and total fruit yield, number of fruits harvested per m², leaf length, plant growth, number of nodes on the main stem, stem diameter, and distance from the apex to the last open flower were prominent. Except for this last characteristic, for which no significant differences between the rootstocks were found, the CM334 rootstock negatively affected all of the agronomic and morphological characteristics, whereas rootstock AR96029 had a positive effect by significantly increasing the plant growth and yield. Additionally, the Tresor rootstock induced an increase in the leaf length and number of marketable fruit without increasing the fruit yield. This evidence indicates that the rootstock had a significant influence on the morphological and agronomic characteristics of the scion. For the production of peppers, therefore, the proper selection of rootstock prior to performing the graft is suggested.

Keywords:

• Capsicum annuum
• grafting
• morphological changes
• rootstock
• scion
• sweet pepper

Acknowledgements

We thank SAGARPA and SDA for their support on the project, “Technology Transfer in Protected Horticulture for the State of Guanajuato,” where this work was partially funded; it was managed by Fundación Guanajuato Produce and carried out in INIFAP during the crop years 2008–2009.