Production of ancho chili graft on criollo de morelos 334 for the control of Phytophthora capsici
Phytophthora capsici is an oomycete that causes losses in the production of chili peppers (Capsicum annuum L.) worldwide. There are currently no varieties of chilies resistant to this pathogen and the chemical products used for its control promotes the development of resistent strains and environmental damages. Therefore, strategies like grafting are used, which stands out for its harmlessness to the environment and its efficiency for controlling soil pathogens. The in vitro resistance of P. capsici from four commercial chili stocks and from the serrano type Criollo de Morelos 334 (CM334), was evaluated in this study. The 334 was chosen due to its low sympton incidence (1 %). In greenhouse the resistance of ungrafted and grafted P. capsici chili pepper plants on CM334 was evaluated, and some morphological variables were measured, as well as the production of commercial fruits in the presence and absence of the pathogen. In regard to the effect of the pathogen on the grafted plants, the interaction with P. capsici did not affect the weight of commercial fruits (FC), although it did significantly reduce the foliar area (AF) and diameter. In the absence of the pathogen, ungrafted plants were significantly taller, they had greater dry weights of the leaves, AF, FC weight, and a lower harvest index. However, all the ungrafted Rebelde plants inoculated with P. capsici died. The yield of commercial fruits of Rebelde in the absence of P. capsici was 14 t ha-1, whereas that for Rebelde grafted on CM334 was 11.4 t ha-1 (p£0.01). This evidence shows that the use of CM334 as a patrón has a potential for the production of chili peppers in areas with high incidence of P. capsici.