Tolerance of several Novi Sad sunflower hybrids to phomopsis stem canker under natural infection

Abstract

Sunflower diseases have a major impact on sunflower yield and quality of seed. When conditions during vegetation are favorable, the intensity of damage can be very high. Therefore, surveys of economically important diseases are necessary. A survey of incidences and severity of phomopsis stem canker was performed on 9 locations during 2007 and 2008. A total of 8 hybrids per location was examined. Lodging of plants as a symptom of stem canker disease was not detected. The mean disease incidence was less than 5%, depending on hybrid, location and year. Generally, higher deasease incidence was recorded in the first year of survey than in the second. The hybrids Velja, NS-H-111 and Baća demonstrated an elevated level of resistance. Despite significant differences in disease severity that was found among the hybrids tested, all of them were highly resistant to phomopsis stem canker.

Suncokret predstavlja našu najvažniju biljnu vrstu za dobijanje kvalitetnih biljnih ulja. Napada ga više od 40 raznih prouzrokovača bolesti od kojih samo određeni broj predstavlja problem u proizvodnji. Praćenje njihove pojave je značajno sa aspekta suzbijanja jer doprinosi stabilnosti proizvodnje. Pojava mrko-sive pegavosti stabla praćena je 2007. i 2008. godine u mreži demonstracionih ogleda. U prvoj godini posmatranja zabeležena je veća pojava bolesti na svim lokalitetima u odnosu na drugu godinu. Među hibridima u obe godine posmatranja najveća otpornost prema Phomopsis heliathi zabeležena je kod hibrida NS-H-111, Velja i Baća. Uprkos značajnim razlikama u intenzitetu pojave mrko-sive pegavosti stabla između hibrida, nije zabeležena jača pojava bolesti iz čega proizilazi da posmatrani hibridi poseduju visok stepen otpornosti prema Ph. helianthi u agroekološkim uslovima Vojvodine.