Glasilo biljne zaštite, Vol. 13 No. 4, 2013.
Professional paper
Forecasting and chemical control of early blight (Alternaria solani Soraurer) on potato
Milorad Šubić
; Poljoprivredna savjetodavna služba Podružnica Međimurske županije, Čakovec
Abstract
During the potato vegetation (May-June-July-August) in 2011 and 2012 the average temperature was +1.54°C higher and the average rainfall was +8,5 mm higher than the thirteen-year average in Medjimurje (1990-2002) (18.57°C and 307,4 mm). Free moisture (from rain, irrigation, fog or dew) (4-20 hour) and higher temperature (17-29°C) are favorable for potato infection with Alternaria solani (early blight). Under these conditions tuber yields was reduced about 50 % on fungicide-untreated field (cv. agria). We collected this data from potato field in Belica and Orehovica with "iMetos" Pessel instruments. A system of weather-based disease forecasting called "TomCast" can be used to time fungicide applications for early blight. The first fungicide applications should occur when 15-30 disease severity values (DSV) have accumulated since beginning of May (depending of time potato seedling and variety susceptibility). Subsequent applications should occur when 20-25 DSV's have accumulated since the previous application if azoxystrobin, pyraclostrobin & boscalid or difenconazole are used.
Keywords
early blight; Alternaria solani Sorauer; potato; forecasting; chemical control
Hrčak ID:
169018
URI
Publication date:
1.5.2013.
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