SISTEMA DE ALERTA FITOSSANITÁRIO DE SEPTORIOSE EM TOMATEIRO DESTINADO AO PROCESSAMENTO INDUSTRIAL

Abstract

Septoria or septoria leaf spot is caused by the fungus Septoria lycopersici Spegazzini, and is considered the most important and devastating disease of tomato crops for industrial processing in Brazil, occurring in all producing regions of the culture. Factors such as temperatures between 20 and 23°C, high relative humidity and a longer period of leaf wetness, result in greater disease severity and pathogen dissemination. In this way, the use of a phytosanitary alert system can help the producer to define the best time to apply fungicides. The objective of this work was to evaluate the TomCast phytosanitary alert system, based on disease severity values (VSD), as a tool to aid in the management of septoria in tomato crops for industrial processing. The experimental design used was randomized blocks (DBC), with five treatments and eight replications. The experimental plot consisted of 3 single lenes off cv. H9553 (0.33m vetem plants x 0.90m between rows). The treatments started at 7 Days After Transplanting (DAT) and consisted of: weekly calendar application, VSD 15, 20 and 25 and the control, which did not receive any fungicide application. Severity was assessed using the grade scale developed by Quezado-Durval et al. (2011), between 71 and 118 DAT. At 121 DAT, the harvest was carried out. In the end, based on the number of fungicide applications and productivity, the economic viability of each treatment was estimated. All treatments differed in relation to the control for the control of septoria. The treatment with VSD 25 reduced by 37.5% the number of fungicide applications in relation to the calendar, not statistically differing the productivity values, in addition, it presented greater economic viability.