SITUACIÓN FITOSANITARIA DE TUBÉRCULOS DE PAPA PRODUCIDOS EN TRES LOCALIDADES DEL MUNICIPIO DE CALIMAYA, ESTADO DE MÉXICO

Abstract

In the agricultural region of Valle de Toluca, State of Mexico, the potato crop is attacked by insect pests and diseases caused by fungi, bacteria, nematodes and viruses, which affect the tubers, causing a decrease in yield and quality. This research was carried out during the spring-summer 2021 agricultural cycle in three commercial plantations of potato cv. Fianna in the localities of Zaragoza de Guadalupe, Santa Cruz Pueblo Nuevo and San Lorenzo Cuauhtenco, municipality of Calimaya, Mexico, with the objective of determining the phytosanitary situation of the tubers produced in the potato zone of this municipality. After the desiccation of the foliage of the plants and suberization of the tuber, a sampling was carried out in each plot using the method of five golds, collecting 80 tubers per sampling point for a total of 400 per plot. These were processed in situ, washed with clean water to remove the dirt adhered to the skin and to be able to observe the symptoms and damage caused by pests and diseases. The tubers with symptoms of "black scab", "dry rot", "common scab" and "soft rot" were quantified; likewise, the tubers with external and internal damage by the insect pests "paratrioza" and "gallina ciega" were counted. With these data, the incidence and severity of each of the evaluated diseases and pests was determined, and the commercial yield of harvested tubers per plot was estimated The four diseases and two pests studied only occurred in potato tubers from the commercial plot of San Lorenzo Cuauhtenco, Calimaya, State of Mexico. Of the four diseases evaluated, the most important in the Calimaya potato zone was "common scab" caused by Streptomyces spp., since it occurred in the three locations with an average incidence and severity of 42.34 and 20.04%, respectively. The disease with the lowest incidence and severity in the area was the "black scab" with 8.96 and 5.15% on average, respectively. The damage caused to the tubers by the attack of paratrioza and blind chicken were relatively low, since the incidence and severity of the two pests did not exceed 14 and 10%, respectively. Overall, the incidence and severity of tuber pests and diseases affected the commercial yield of potato cv. Fianna in the producing area of Calimaya, since this was 28,333 t ha-1, and it was lower than the state (29,560 kg ha-1) and national (31,780 kg ha-1) average yield.