PROBLEMS IN CONTROL OF EARLY BLIGHT IN TOMATO

Alternaria solani Sorauer, the causal organism of early blight has, for the last six years, been the important leaf parasite due to its reduction of tomato assimilative capacity and fruit quality.
There is permanent danger of infection and an increase in disease intensity after flowering, especially during a hot summer and when irrigated.
The performance of protective fungicides alone, or combined with systemic products on A. solani control were investigated and the same effects in leaf and fruit protection were noticed.
The well timed early treatment with protective fungicides of the less susceptible cultivar Mobil resulted in a decrease in disease spread on foliage, stem and fruits.
The limitations of time and number of applications of protective fungicides (copper compounds, mancozeb, folpet and metiram) reduced their efficacy to under 80% in late treatments and required the spray interval to be shortened to less than 10 days.

Efficacy of leaf and fruit protection in late treatments dropped to 50 – 60% and 55 – 62%, respectively.
Protective fungicides in combination with propamocarb or metalaxyl showed the same efficacy in the control of late infections.

I Balkan Symposium On Vegetables and Potatoes

Z. Klokocar Šmit, D. Inðjic, R. Jakovljev, F. N-Dzi, P. Mitrovic

Alternaria solani, folpet, mancozeb, metiram, metalaxyl, propamocarb

https://doi.org/10.17660/ActaHortic.1997.462.101