Evaluation of two bio-fungicides for control of leaf rust (Puccinia triticina Eriks.) on durum wheat cultivar CIRNO C 2008

Abstract

Leaf, stem, and stripe rusts are the most important diseases of wheat worldwide. In southern Sonora, Mexico, leaf rust is endemic and has caused serious epiphytotics; proper control relies on breeding for resistance and fungicide applications. The extensive utilization of chemicals to control diseases of plants, the emergence of resistant phytopathogens to fungicides, and the damage to the health of producers and consumers, has promoted the search for viable alternatives that guaranty a sustainable agriculture production, minimizing the impact on the environment. In this work, the biofungicides Roya Out® and Best Ultra®F were evaluated for control of leaf rust on cultivar CIRNO C2008, under a randomized complete block experimental design with three replications. After one application of the biofungicides and the inoculation with a urediniospore suspension, two other applications were carried out. Disease severity was evaluated following Cobb´s modified scale and the analysis of variance was performed with SAS, and the mean comparison with Duncan´s multiple range test (α = 0.05). Other variables measured were: spike length and weight, number of grains per spike, grain length and weight, a thousand grain weight, and grain yield per plot. The disease showed up during the soft dough stage and disease severity was 32% for plots treated with Best Ultra®F, 27% with Roya Out®, and 25% in the untreated check plots. Despite the infection, the highest grain yield estimated was obtained from plots treated with Roya Out® (7.22 t ha-1), followed by Best Ultra®F (7.03), and the untreated check (6.12 t ha-1).