Modification of the TOMCAST Model with Aerobiological Data for Management of Potato Early Blight

Laura Meno,Maria Carmen Seijo,Maria Shantal Rodríguez-Flores,Olga Escuredo

doi:10.3390/agronomy10121872

Abstract

The present study focuses on establishing thresholds of weather variables for predict early blight in potato crops. For this, the TOMCAST model was adjusted using weather variables and Alternaria conidia levels (mainly A. solani and A. alternata) during six growing seasons in A Limia (Northwest Spain). TOMCAST for the effective management of early blight considers leaf wetness and air temperature to calculate daily severity values (DSVs). Spearman correlations between temperature (minimum and average), mean temperature during leaf wetness period and Alternaria concentration showed the highest positive significant coefficients (0.386, 0.230 and 0.372, respectively; p < 0.01). Specifically, Alternaria levels higher than 50 spores/m3 were found the days with air mean temperature above 18 °C, more than 7 h of leaf wetness. Leaf wetness was decisive to estimate the concentration of Alternaria, resulting in a significant linear regression model (R2 = 0.41; p < 0.001). TOMCAST was adapted to the area, considering 10 °C the minimum threshold for the mean value of temperature during the wet period and 10–15 accumulated disease severity values (DSV). Using TOMCAST, it was possible to predict the first Alternaria peak in most of potato growing seasons. Combining aerobiological and meteorological data to control fungal diseases during crops are a useful tool for sustainable agriculture.

Highlights

The potato (Solanum tuberosum L.) is the world’s fourth-most important crop after rice, wheat and maize, and the first among non-grains [1]
This study showed the influence of wet period or the hours of leaf wetness, as well as the existence of interrupted wet periods as favorable conditions for the presence of Alternaria
The present study contributes to the knowledge of the main weather factors that affect the formation of Alternaria conidia in the air of a potato crop

Summary

Introduction

The potato (Solanum tuberosum L.) is the world’s fourth-most important crop after rice, wheat and maize, and the first among non-grains [1]. Spain produces less than 4% of European potato production, but in some Spanish areas such as A Limia, this crop is the primary income source for people. The potatoes are alternated with cereal crops generating many jobs for families. The sandy and silty soils together with weather conditions during summer, increase the agricultural drought risk and forcing growers to practice irrigated agriculture [2]. These conditions provide the ideal environment for the development of fungal diseases on potato plants. When ideal conditions occurred over time, the disease gets worse having a negative impact on yields

Methods

Results

Discussion

Conclusion