The objective of the study was to evaluate the reaction of Theobroma cacao clones to the artificial inoculation of Moniliophthora roreri, at the Tulumayo Experimental Station, Tingo María. Eleven “S” clonal hybrids and 3 “C” farmer collection clones were studied. Conidia of M. roreri were inoculated into 65-day-old fruits, protected for 48 h in a humid chamber. Incidence, external severity (SE) according to fruit damage in degrees were evaluated weekly, 0: healthy fruit, 1: hydrosis, 2: swelling, 3: necrosis, 4: mycelium that covers ¼ part of the stain and 5: mycelium that covers more than ¼ part of the stain, and internal severity (SI): percentage of necrotic grain in each fruit, the clones being compared by ANOVA and Tukey’s test (α = 0.05). The results show a high incidence in all the clones, with values of 91.67 to 100%. Clone S-19 showed the lowest SE, which was 2.64, ...

Between 2011–2013, yellow rust unleashed one of the most important phytosanitary crises in the coffee sector in Peru, causing a negative impact on the rural family economy. One of the factors associated with the intensification of the disease was the predominance of susceptible cultivars in agricultural systems. Faced with the need to rehabilitate the coffee park with new cultivars, the National Institute for Agrarian Innovation (INIA) has managed the installation of basic coffee germplasm for the development of the yellow rust resistance program, which is made up of 169 introductions from the departments of Pasco, Junín, Huánuco, Ucayali, Cajamarca, and Amazonas and obtained from 2015. The objective of the study was to evaluate the incidence and severity of epidemic conditions in the field and characterize the components of horizontal resistance, using the method of inoculations of ...