Strawberry (Fragaria ananassa) plants showing symptoms of leaf spot were found in the producing areas of Manchay Bajo, Pachacamac District, Lima, Peru. The responsible pathogen was isolated and observed under a microscope to examine its morphological characteristics and the size of its structures, resulting in its identification as the fungus Corynespora cassiicola. Healthy strawberry plants that had been inoculated with C. cassiicola in a greenhouse developed lesions after 3 days and exhibited symptoms consisting of dark brown spots that had light brown centers and were surrounded by yellow halos, which coalesced and subsequently caused necrosis of the whole leaf. In vitro tests demonstrated that the fungus Trichoderma harzianum strain T-22 showed antagonistic activity against C. cassiicola, causing 41.8% mycelial growth inhibition, and the fungicides fosetyl-aluminum (Aliette®) and th...

The present study aimed to determine the contribution of the genetic effect of bulls used via artificial insemination on the dairy production of Brown Swiss cows from the El Mantaro Agricultural Experiment Station of the National University of Central Peru, in terms of daily milk production (PLD) and by lactation (PLC). In total, 112 lactations were used, from a total of 49 cows, daughters of 7 Brown Swiss bulls, standardized to 305 days (PLE) and two milking by non-linear projection. The statistical analysis was carried out by using a mixed linear model, considering as fixed factors the number of lactations, year, season and age at calving of the cow, and as a random factor the genetic effect of the bull. Corrected phenotypic means were obtained for PLD and PLC with the correction factors obtained from the model, and predictions of the predicted transmission ability (PTA) of the evaluat...