Yellow Sigatoka monitoring methods in the subtropical climate of Southern Brazil

Abstract

The adoption of monitoring systems to control the Sigatoka disease complex represents one of the most significant advances in banana production worldwide. In this paper four methodologies for evaluating Yellow Sigatoka (Biological Pre Warning - BPW, Stage of Evolution - SE, Infection Index - II, and Youngest Leaf Spotted - YLS) were compared under experimental conditions, and two methods were selected for commercial orchards in subtropical conditions. These monitoring systems were submitted to correlation (P<0.05 error) and statistic descriptive analysis. The disease monitoring systems presented different values depending on the methodology in the experimental phase. The highest absolute values were verified in the BPW (8450 points), followed by SE (3213 points), II (36.3%), and YLS (9.7). The YLS presented a strong negative correlation with BPW (-80.7%), while the BPW and SE had a weak correlation (37%). In the commercial orchads BPW and YLS were compared, but the low frequency of the variable YLS limited its application for Sigatoka evaluation. After comparing the two systems in commercial orchards, we found that BPW should continue being the standard disease monitoring method on the coast of the state of Santa Catarina.

Keywords

• Mycosphaerella
• Bioclimatic pre warning
• Youngest leaf spotted
• Severity