Susceptibility of some experimental sunflower hybrids to white rot (Sclerotinia sclerotiorum) and broomrape (Orobanche cumana)

Abstract

The susceptibility of 10 experimental sunflower hybrids to the causal agent of white rot (S. sclerotiorum) and broomrape (O. cumana) was tested at two localities (Bečej and Svetozar Miletić) in naturally highly infested fields in 2009. There are significant differences between hybrid susceptibility to white rot and broomrape. The basal stalk rot was absolute dominant type of disease and was evident on 16.7 % of plants in Bečej. In Svetozar Miletić fungus attack did not noticed in any tested hybrid. Broomrape attack was noticed on six tested hybrids at both localities. It can be observed that hybrids in Bečej had significantly higher yields compared to those achieved in Svetozar Miletić. Genetic capacity of the hybrids and favorable conditions for sunflower growth had the most important influence of achieved seed yield. Negative influence of white rot attack on seed yield was lower because it appeared in root and stalk form. Although on certain plants broomrape attack was of high intensity generally it was not so sever and therefore harmfulness of this parasitic plant could not manifest significant influence on seed yield