Performance of eleven plum cultivars under agroclimatic conditions of Plovdiv region, Bulgaria

V. Bozhkova*, P. Savov

Fruit Growing Institute, 4004 Plovdiv, Bulgaria
(Manuscript received 13 May 2016; accepted for publication 8 June 2016)

Abstract. Plum is a traditional fruit crop in Bulgaria. The South Central Region represents 22.2% of the total area occupied with plum trees. In this study the results of a four years’ investigation on ten plum cultivars carried out at the Fruit Growing Institute in Plovdiv are presented. Stanley was used as a standard. The observed phenological characteristics included flowering and fruit ripening. The cultivars Tophit plus and Toptaste are the earliest flowering, whereas Topstar plus is the latest one. Fruits of Topfirst cultivar ripen at the beginning of July, those of Top and Tophit plus in September and all the rest in August. According to biometrical analyses, fruit weight of Topgigant plus and Tophit plus is over 60g. The total soluble solid content in the studied cultivars varies from 15.7% in Top cultivar to 24.75% in Toptaste. Yield was determined and expressed in kg per tree. Over 30 kg per tree was harvested from the cultivars Stanley, Jojo, Topgigant plus and Tophit plus. The lowest yield was obtained from the cultivars Top, Topfive and Toptaste. In 2012, the percentage of flower buds destroyed by frost was evaluated. The lowest degree of damages was reported in the cultivars Tophit plus, Topgigant plus and Mirabelle de Nancy (below 10%), and the greatest damages in Toptaste (51%). According to the obtained results, the most suitable plum cultivars recommended to be grown in Plovdiv region, are Jojo, Topgigant plus and Tophit plus, as well as the cultivar Bellamira from the group of Mirabelle plum.