Abstract

PALOMARES-PEREZ, Martín et al. Cacarizo of nopal in Opuntia ficus-indica L. Miller, Milpa Alta, México City. Agrociencia [online]. 2016, vol.50, n.7, pp.877-887. ISSN 2521-9766.

Milpa Alta, in the south of Mexico City, is the most important production zone of nopal (Opuntia ficus-indica) in the world, and is consumed as a vegetable. In this location, there are symptoms known as nopal cacarizo, related to the presence of red chinch bug (Hesperolabops nigriceps), and despite the importance of the crop, there are no studies about the distribution of nopal cacarizo. To determine the distribution, incidence and severity of the disease, samplings were made in vegetable nopal plantations in different geographic points of Milpa Alta. A logarithmic diagram scale was constructed to evaluate its severity, and correlated to nopal cacarizo with H. nigreceps. Aggregation and dispersal indices of Morisita and Lloyd were also estimated. Nopal cacarizo is distributed throughout Milpa Alta with some aggregation in the west (Morisita=1.768; Lloyd=2.535), as is H. nigriceps (Morisita=1.003; Lloyd=1.006). Furthermore, there was a close relationship between nopal cacarizo and H. nigriceps (r=0.765). Damage to individual plants is concentrated in the basal, second and third cladodes. Using the logarithmic diagrammatic scale, with acceptable precision (r2=0.988) and exactness (b1=1.012), an incidence of 56.4±18.5 % was established along with a severity of 10.5±6.4 % of nopal cacarizo in Milpa Alta. This is evidence of the importance of the symptoms in plants of Opuntia, the need to know the phenomenon and the conditions that favor its dispersion.

Keywords : Hesperolabops nigriceps; vegetable nopal; symptoms.

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