Dynamics of coastal weather effects on Moler disease in Indonesia shallot production

Abstract

Importance of the work: Coastal microclimatic factors influence pathogen dynamics;
however, their impact on shallot diseases, such as Moler disease, remains poorly understood.
Objectives: To investigate multivariate relationships between coastal weather parameters
and Moler disease development in shallot production systems.
Materials and Methods: Field surveys were conducted across 15 sites in Parangtritis,
Yogyakarta, Indonesia, during the late rainy and dry seasons. Disease incidence and
infection rates were assessed weekly alongside six weather parameters monitored via
an automatic weather station. Principal component analysis (PCA) was used to analyze
weather-disease relationships.
Results: Disease incidence was significantly higher during late rainy season (28.50%)
compared to dry season (12.03%, p = 0.03), with infection rates of 0.14 units/d and
0.09 units/d (p < 0.001). The PCA revealed 84.62% of the weather-diseases relationship
variance was explained by the two principal components. Radiation-precipitation
variables had strong positive associations with infection rates, while relative humidity
had an unexpected negative correlation (Pearson’s correlation coefficient r = -0.55).
Temperature had a secondary influence through weak through positive F2 loadings
(25.54%, r = 0.25).
Main finding: Coastal weather-disease interactions deviated from inland patterns,
particularly in humidity-disease relationships, necessitating maritime-specific disease
prediction models for effective management.