Relationship between the conidia production of Pyricularia oryzae on wheat leaves and the blast disease development in wheat spikes

Given the scarcity of information about inoculum sources of Pyricularia oryzae pathotype Triticum (PoT) under field conditions, this study quantified the conidia of PoT on wheat leaves during the crop cycle and linked them with the presence of blast in the spikes. The study was conducted involving two different production environments: nine commercial wheat fields and an experimental plot under sprinkler irrigation. Throughout the crop season, leaves were collected monthly and processed to quantify the number of conidia present in each gram of dry leaves. At physiological maturity of the crop, the fields were sampled to quantify the number of infected spikes/m2. Significant differences in the quantity and persistence of the pathogen during the cycle were seen under both environments. A strong positive correlation between the number of conidia present on the leaves during the crop growth cycle and the percentage of damaged spikes was established.