Sensitivity of promising cherry hybrids and new cultivars to economically important fungal diseases

Abstract

Abstract. As a result of years of developing the breeding programme for creating novel sweet cherry cultivars in the Fruit Growing Institute (FGI), Plovdiv, a reach hybrid fund from first and second hybrid generation is created. Of the selected and propagated hybrids at a more advanced stage of testing are 11 hybrids along with three new cultivars of the FGI Plovdiv ('Kossara', 'Rosalina' and 'Trakiiska hrushtyalka') grafted on three rootstocks were tested for sensitivity to causers of economically important fungal diseases in sweet cherry - cherry leaf spot (Blumeriella jaapii (Rehm) Arx), shothole blight (Stigmina carpophila (Lev.) Ellis) and brown rot (Monilinia fructigena (G. Wint) Honey). The degree of infestation under field conditions is reported by determining the index of attack on leaves and fruit, using the formula of McKinney. As the most sensitive elites are outlined elite El.17-31 (to cherry leaf spot) and elite El.17-136 (to shothole blight). The cultivars 'Kossara' and 'Trakiiska hrushtyalka' exhibit an average resistance to the three diseases, as the values for the index of infestation are lower or similar to those of standard cultivars 'Van' and 'Bing', while 'Rosalina' demonstrated sensitivity to shothole blight and brown rot. Interesting is the elite El.17- 37 demonstrating the least infestation of Blumeriella jaapii - 7.33% and Monilinia fructigena - 6.67%. The same has a set of valuable qualities as late maturing date and very large fruits with excellent sensory profile, making it a potential candidate cultivar.

Keywords

• Prunus avium
• sweet cherry
• hybrid
• breeding
• fungal diseases