RELАTIONSHIP BETWEEN PОPULATION DENSITIES OF Globodera rostochiensis AND YIELD OF PОTATO CULTIVARS UNDER FIELD CONDITIONS IN BULGARIA

Abstract

In 2010–2011, in field conditions (Smolyan potato growing region) microplots experiment have been carried out to determine the effect of population densities of Globodera rostochiensis pathotyp 3 (Ro3) on the growth and yield of two new Bulgarian potato (Solanium tuberosum L.) varieties Evridika and Orfei. Microplots were 25 cm-diam, 30 cm-deep, filled with 10 L of soil infested with G. rostochiensis in a geometric series of nematode densities between 0 and 64 eggs/mL of soil. Eight weeks after planting in infested soil, the relative plant height of varieties Evridika and Orfei was reduced at Pi ≥ 1 and 32 eggs/mL soil, respectively. In both potato varieties the minimum possible relative values for plant height were 0,51 and 1,0, respectively, at Pi = 64 eggs/mL soil. The tolerance limits of potato yield of Evri-dika and Orfei were 2 and 16 eggs/mL soil, respectively. The minimum possible relative values for yield of Evridika and Orfei were 0,325 kg/plant and 0,659 kg/plant, respec-tively, at Pi = 64 eggs/mL soil. A mathematical model describing the influence of Pi of G. rostochiensis and yield of both varieties can be used in expert advisory systems when accounting for the environmental factors.

Keywords

• potato cyst nematode, solanum tuberosum l., pathogenicity, potato, globodera rostochiensis, tolerance limit, yield losses