OCCURRENCE OF DISEASES ON SUNFLOWER STEMS IN EASTERN CROATIA

• Main Authors: Jasenka Ćosić, Draženka Jurković, Karolina Vrandečić, Tomislav Duvnjak
• Format: Article
• Language: English
• Published: Faculty of Agrobitechnical Sciences Osijek 2005-06-01
• Series: Poljoprivreda
• Subjects: sunflower; stem diseases; Phomopsis helianthi; Sclerotinia sclerotiorum
• Online Access: http://poljoprivreda.pfos.hr/upload/publications/2_COSIC(1).pdf
• ISSN: 1330-7142; 1848-8080

During a three–year period (2001-2003), occurrence of diseases on sunflower stems was monitored in fields of PIK Vinkovci (on the Sopot location). The experiment involved 24 genotypes planted in 2001, 30 genotypes in 2002, and 20 genotypes in 2003, each of them repeated in two trials: treated and non-treated. The Konker fungicide preparation, dosed 1.5 l/ha, was used for sunflower protection. The treatment was applied at the R1-R2 development stage of sunflower (the size of immature bud was up to 2 cm). Based on the conducted survey, it was found out that Sclerotinia sclerotiorum was the most dominant disease agent to sunflower stems in 2001. Percentage of infection for the non-treated and treated trials was between 0 and 32.5%, and 0 and 17.5%, respectively. In 2002 and 2003, Phomopsis helianthi was the most dominant disease agent. Average value rate in 2002 fluctuated between 0.65 and 4.00 in non-treated trial and between 0.05 and 2.60 in treated trial. In 2003, occurrence of P. helianthi was of weak intensity, mostly because of unfavorable weather conditions for parasite development. Average ratings were 0.35 to 3.30 in the non-treated trial, and 0.20 to 1.85 in the treated trial. Application of fungicide during the whole experiment period had positive effects on the decrease of infection intensity and the increase of grain and oil yields.