Heart-shaped cladodes in commercial cactus pear plantations

Authors

  • M. E. Mendoza-Orozco
  • I. Hernández-Ríos
  • F. J. Morales-Flores
  • J. Mena-Covarrubias
  • J. Ortega-Espinoza
  • C. Mondragón-Jacobo
  • S. de J. Méndez-Gallegos

Keywords:

Opuntia, physiopathies, etiology, diseases, productivity.

Abstract

Because of the diverse uses it has, and the multiple benefits it contributes to, cactus pear
(Opuntia spp.) is considered one of the natural resources of greatest socioeconomic
importance in Mexico. Its intensive production in monoculture, associated with a reduced
genetic variability, has resulted in the proliferation of various physiopathies, and the prevalence
of pests and diseases, which reduce its productivity. In diverse cactus pear producing zones in
Mexico and other countries, a malformation called in this study cladode ‘acorazonamiento’
(heart-shaped cladode), which is derived from the shape the cladode takes, has been
observed; however, the causal agent is unknown at the time. Considering that its occurrence
could cause economic losses to cactus pear producers, this study describes the visual
symptomatology and the incidence and severity of heart-shaped cladode symptoms in
commercial cactus pear plantations in the south and southeast of Zacatecas, Mexico. The
symptomatology was more evident in tender buds of 6 to 20 days of age, and is characterized
by the presence of diverse malformations in the apical or lateral part of the cladodes, as well
as by the appearance of micro-scarring that reduces the vegetative and floral budding in the
affected zone; the damaged tissue presents rupture of the cuticle and epidermis, and the
detachment of cell walls. Three principal malformation symptoms were found, which were
named in this study as: ‘heart’, ‘bean’ and ‘saw’, according to the cladode physical appearance,
with the first one being the most frequent. All the plantations evaluated showed the presence
of malformed cladodes, with values that fluctuated between 12 and 30 %. Cladodes with heartshape
symptomatology may generate buds with similar appearance in a proportion of 2:1
asymptomatic:symptomatic cladodes. Likewise, it was observed that the degree of severity
ranged between 1 to 38% of photosynthetic area reduction, and damaged cladodes may lose
between 50 to 80% of vegetative and floral buds. Derived from this, it is pertinent to perform

studies directed towards characterizing its etiology in order to implement management
strategies and reduce economical losses.

Published

2018-04-09

Issue

Section

Scientific Papers