Plant protection, and especially the efficiency of protection against mycosis, is a very important production technological element concerning sunflower. The efficiency of production can be increased on the basis of a thorough pathological survey and its results carried out in a wide variety of hybrids, as the features of hybrids, the reactions of genetic bases to pathogens can be found out under domestic conditions.
The tests were carried out at variety-test lots of OMMI for hybrids used for food or oil and other sunflower varieties admitted by the state at the Experimental Site DTTI Látókép, Centre of Agricultural Sciences, University of Debrecen between 1998 and 2002. The number of the tested hybrids was 49 in 1998, 45 in 1999, 49 in 2000, 55 in 2001, and 44 in 2002.
Due to the infection source of high amounts remained from 1997 and the favourable weather conditions for the pathogens, an infection of high degree was experienced in the tested stands. The lowest infection index in the hybrids with a very short vegetative period was experienced with Beni hybrids. Comparing to the average of the hybridgroup with short vegetative period, a low infection index characterised the Baleno, Trident, IBH-166, Hysun 321, Resia, Alexandra, Cergold and Pixel hybrids. In 1999, among hybrids with medium vegetative period, Zoltán, Zsuzsa and Util hybrids could be highlighted because of their low infection index. In 1998, among confentionary hybrids, Marica-2 hybrid had the most favourable index values (2,55).
During our trials, the experienced infection dynamics were compared in the event of hybrids with higher and lower susceptibility under different sowing technological elements. The results call for the fact that when a hybrid with higher susceptibility is produced, production technological elements, such as the time of sowing, influence considerably the damage caused by the pathogen, therefore it must not be ignored when its determination takes place. In the event of hybrids with lower susceptibility the change of the tested production technological elements within the biological optimum does not lead to the increased risk of the damage caused by Diaporthe helianthi.