PRELIMINARY RESULTS FROM INVESTIGATION ON APPLE PROLIFERATION
Apple proliferation (AP) caused by Candidatus Phytoplasma mali is an economic important phytoplasma disease on apple (Malus domestica Borkh.), affecting almost all cultivars, reducing size, weight and quality of the fruits, as well as reducing tree vigour and increasing susceptibility to powdery mildew. The disease was detected in Bulgaria in early 1960s by Trifonov (1965). After 1975 consequent studies had been sporadic and uncompleted. The current paper reports the preliminary results from surveys on occurrence and incidence of AP. At that stage, apple trees, growing in private and experimental orchards in Plovdiv district of Bulgaria were tested. The detection of the phytoplasma in apple plants was carried out by symptom observations in the field, enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). Visual observations for the symptoms of apple proliferation were made during 3 vegetative cycles. The results obtained showed that the incidence of AP, in the observed orchards varied from 7.4% to 24%. The most infected cultivar was Remo - 35% of all tested Remo trees.
Milusheva, S. and Terziev, I. (2013). PRELIMINARY RESULTS FROM INVESTIGATION ON APPLE PROLIFERATION. Acta Hortic. 981, 513-515
apple, proliferation, phytoplasma, incidence