Variable climate suitability for wheat blast (Magnaporthe oryzae pathotype Triticum) in Asia: results from a continental-scale modeling approach

Abstract

Crop fungal diseases constitute a major cause of yield loss. The development of crop disease monitoring and forecasting tools is an important effort to aid farmers in adapting to climate variability and change. Recognizing weather as a main driver of fungal disease outbreaks, this work assesses the climate suitability for wheat blast (Magnaporthe oryzae pathotype Triticum, MoT) development in Asian wheat-producing countries. MoT was reported for the first time in Bangladesh in 2016 and could spread to other countries, provided that environmental conditions are suitable to spore development, distribution, and infection. With results from a generic infection model driven by air temperature and humidity, and motivated by the necessity to assess the potential distribution of MoT based on the response to weather drivers only, we quantify potential MoT infection events across Asia for the period 1980–2019. The results show a potential higher incidence of MoT in Bangladesh, Myanmar, and some areas of India, where the number of potential infection (NPI) events averaged up to 15 during wheat heading. Interannual trends show an increase in NPI over those three countries, which in turns show their higher interannual variability. Cold/dry conditions in countries such as Afghanistan and Pakistan appear to render them unlikely candidates for MoT establishment. The relationship between seasonal climate anomalies and NPI suggests a greater association with relative humidity than with temperature. These results could help to focus future efforts to develop management strategies where weather conditions are conducive for the establishment of MoT.

Weather-based logistic regression models for predicting wheat head blast epidemics

“…Cardoso et al (2008) showed that although the optimal temperature for infection is 25°C, the disease can still establish at cooler conditions (≤20°C) conditioned to extended period (> 30h) of moisture. Indeed, moisture conditions have been shown to significantly influence the potential infection of PoT (Montes et al, 2022) and PoL (Lolium lineage) (Mills et al, 2020). These authors further hypothesized that the significant role of relative humidity during the heading stage can be attributed to its influence on germination and infection process, as previously observed in the case of MoO (Oryzae lineage) (Suzuki, 1975).…”

Modelo predictivo de la severidad del tizón foliar por Cercospora kikuchii mediante variables meteorológicas

“…Otros antecedentes en modelos predictivos que refuerzan los resultados obtenidos en la presente investigación, donde no solo las precipitaciones fueron importantes en la evolución de una enfermedad, fueron los obtenidos en Luxemburgo para roya amarilla causada por Puccinia striiformis del trigo (Triticum aestivum), en dicha investigación se obtuvo que en invierno se requieren elevadas humedades relativas (>92 %), temperaturas entre los 4 °C y los 16 °C, y por lo menos cuatro horas por día para que la enfermedad se desarrolle y pueda causar una epifitia (El Jarroudi et al, 2017). Además, en trigo se ha observado una mayor relación con la humedad relativa que con la temperatura, para la evolución de la severidad del quemado del trigo o Pryricularia o Brusone del trigo causado por Magnaporthe oryzae pathotype Triticum en Asia (Montes et al, 2022).…”

The response of stomatal conductance to vapor pressure deficit over global wheat areas in CMIP6 warming projections

“…Similarly, the SPAM for wheat area representation corresponds to a static product that might over-and under-estimate the wheat cultivation area (Montes et al, 2022). The latter becomes delicate when assuming that, for example, wheat development and phenology should also be affected by global warming (Jägermeyr et al, 2021).…”