OTIORRHYNCHUS LIGUSTICI L. (COLEOPTERA: CURCULIONIDAE) III. MODELING SCALE FOR RESISTANCE IN ALFALFA VARIETIES

DOI: 10.7904/2068 – 4738 – III(6) – 81

Ivelina NIKOLOVA, Nataliya GEORGIEVA

 Abstract: In 2006–2009 period in the experimental field of IFC–Pleven were carried out studies with 8 alfalfa varieties included in the Official variety catalog of Bulgaria (2005): Europe (France), Prista 2 (Obraztsov Chiflik, Ruse), Prista 3 (Obraztsov Chiflik, Ruse), Prista 4 (Obraztsov Chiflik, Ruse), Obnova 10 (IFC, Pleven), Pleven 6 (IFC, Pleven), Dara (IFC, Pleven) and Multifoliate (Obraztsov Chiflik, Ruse). For evaluation of the resistance in alfalfa varieties to Otiorrhynchus ligusticiwas developed 5–graded scale based on the numbers of furrows on the root system. Withthe most strongly pronounced damage and high percentage of plants with score 3, 4 and 5 was distinguished the fourth year in alfalfa cultivation. Asmiddle resistance varieties tothe attack from O. lygusticiwere Europe, Prista 2 and Multifoliate (the index of attack was 21.7, 22.9 and 23.0% respectively) which is important for the selection and practice.

Key words: alfalfa varieties, scale for resistance, Otiorrhynchus ligustici