Evaluation of a forecast system for bacterial tomato (Xanthomonas spp.) spot

Abstract

An evaluation of a forecast model of bacterial tomato spot with different levels of disease severity was compared to conventional spraying regime. The following sprayings with severity threshold (ST) of 0.05, 0.15, and 0.25 were carried out, based on the forecast model described by Marcuzzo et al. (2008), and conventional spraying regime with 5- and 7-day
intervals. The results did not reveal any significant differences (P < 0.05) in yield or fruits with symptoms within all treatments. The area under disease progress curve (AUDPC) was reduced by 25.71% for ST 0.15 with the same number of
sprayings carried out weekly. This was not different from AUDPC of ST: 0.05. For ST: 0.25, the number of sprays was
54.1% and 35.3% less compared to 5-day and 7-day spray regime, respectively, and the corresponding AUDPC were 9.83% and 19.66%. The forecast model with severity threshold ST 0.15 reduced the spraying number in relation to the conventional
spraying regime.