Low water availability increases susceptibility to peanut smut (Thecaphora frezzii) in peanut crop

PAREDES JA; GUZZO MC; MONGUILLOT JOAQUIN H; ASINARI F; POSADA GA; ODDINO CM; GIORDANO DF; MORICHETTI SA; TORRES AM; RAGO AM; MONTEOLIVA MI

PLANT PATHOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2023

0032-0862

Peanut smut (causal agent Thecaphora frezzii) and seasonal drought are the two main factors reducing peanut yields in Argentina. There are no previous studies about the effect of drought on peanut smut occurrence. We evaluated the effect of soil water limitation on the smut symptoms in greenhouse and field assays. Additionally, we analyze the biochemical responses in the combined stress caused by water limitation and smut infection in greenhouse experiments. We found that a moderate water deficit (30% of the water in the soil) increased smut symptoms and differentially increased proline and reduced chlorophylls. Then we studied the correlation between field precipitation data and smut damages from 2015 to 2020 in naturally infected fields with a high T. frezzii spore load in the soils. Strong correlations between precipitation and severely affected pods, severity disease index and incidence were found from January to March (susceptibility window for T. frezzii infections). We suggest a specific time-frame irrigation strategy to mitigate smut damage when there is a water deficit in the growing season.