MORPHOLOGY OF PEAR FRUITING BRANCHES

Authors: Aleksandar Radović, Dragan Milatović, Dragan Nikolić, Dejan Đurović, Ivana Bakić, Dejan Zejak, Velibor Spalević

Download: PDF

Abstract: In this study, the morphological characteristics of the fruiting branches of seven economically important pear cultivars (‘Carmen’, ‘Butirra Precoce Morettini’, ‘San ta Maria’, ‘William’s Bon Chretien’, ‘Abbé Fétel’, ‘Conference’ and ‘Curé’) were investigated over a period of two years (2022–2023). The trials included three types of fruiting branches: one-year old spurs, short fruiting shoots and long fruiting shoots. For each type of fruiting branches, length, diameter, the number of mixed and vegetative buds was determined. Significant differences in the characteristics of the fruiting branches were found between the cultivars tested. The cultivar ‘Santa Maria’ had the shortest length of one-year old spurs and short fruiting shoots (1.4 cm and 6.2 cm respectively). The longest length of oneyear old spurs was found in the cultivar ‘Conference’ (3.0 cm), and of the short fruiting shoots in the cultivar ‛Curé’ (10.8 cm). In all cultivars, with the exception of ‛Curé’, one or two mixed buds were also observed in the lateral positions of the short fruiting shoots in addition to the terminal position. The length of the long fruiting shoots varied in an interval from 24.5 cm (‛Carmen’) to 41.4 cm (‛Conference’), and the diameter from 4.6 mm (‛Santa Maria’) to 6.3 mm (‛Carmen’). Apart from the cultivars ‛Conference’ and ‛Curé’, the presence of mixed buds at the lateral positions of the long fruiting shoots was observed in all the other cultivars. The highest number of mixed buds on the long fruiting shoots was found in the cultivars ‘William’s Bon Chretien’ (4.8) and ‘Abbé Fétel’ (4.3). The morphological characteristics of the fruiting branches of pears can be an important parameter for cultivar identification. In addition, they are very important parameters when carrying out pomotechnical treatments, especially in high-density pear orchards.

Key words: Pyrus communis L., cultivar, one-year old spurs, short fruiting shoots, long fruiting shoots

Title: Influence of cultivar and rootstock on phenological characteristics of plum

Authors: Mirjana Radović, Dragan Milatović, Gordan Zec, Đorđe Boškov

Download: PDF

Abstract: The influence of three clonal rootstocks (‘Pixyʼ, ‘Fereleyʼ and ‘St. Julien Aʼ) together with seedlings of Myrobalan (control) on the phenological characteristics (flowering and harvest date) of the plum cultivars ‘Čačanska Ranaʼ, ‘Čačanska Lepoticaʼ and ‘Čačanska Najboljaʼ was studied in the Belgrade region (Serbia) over three years. The meteorological conditions during the study years were a source of variability in the results related to flowering time. The earliest start, full and end of flowering were recorded in the second experimental year, while the latest flowering phase occurred in the first. The rootstocks had no effect on flowering time, while the harvest date was 3–5 days later for the clonal rootstocks than for the seedling rootstock. Among the cultivars, the earliest harvest date was for the cultivar ‘Čačanska Ranaʼ, which also required the fewest days from full bloom to harvest. The study presents the correlation matrix between the investigated indicators of phenological characteristics and air temperatures for the studied combinations of plum cultivars and rootstocks, which shows that the phenological characteristics (flowering and harvest date) are directly influenced by the meteorological conditions in the investigated years.

Key words: Prunus domestica L., cultivar, rootstock, flowering, harvest, correlation

Title: INFLUENCE OF ROOTSTOCKS ON VIGOUR AND PROPERTIES OF LONG FRUITING BRANCHES IN APRICOT CULTIVARS

Authors: Lazarević Milana, Zec Gordan, Đorđević Boban, Milatović Dragan, Đurović Dejan, Boškov Đorđe, Tešić Nemanja

Download: PDF

Abstract: This paper presents the results of studies on the influence of five seedling rootstocks [‛Green Gage’, ‛Belošljiva’, ‛MY-KL-A’ (Myrobalan seedling selection), ‛Iroquois’ and ‛Crvena Ranka’] and one clonal rootstock (‛Myrobalan 29c’) on the vigour and morphological characteristics of the long fruiting branches of four apricot cultivars (‛Buda’, ‛Ruža’, ‛NS-4’ and ‛Novosadska Rodna’). The studies were carried out at the ‘Radmilovac’ Experimental station of the Faculty of Agriculture in Belgrade over a period of three years (2022–2024). The vigour of the trees was determined on the bases of the trunk cross-sectional area (TCSA). The following characteristics of the long fruiting branches were analysed: length, thickness, number of flower buds and vegetative buds, their ratio and flower bud density (number of flower buds per 1 m length of fruiting branch). All investigated cultivars have the highest average TCSA on the rootstock ‛Myrobalan 29c’ (average value for all cultivars 83.81 cm²), while the lowest value of the same parameter was measured on the rootstock ‛Belošljiva’ (average value for all cultivars 54.52 cm²). The values of TCSA of the tested cultivars on the different rootstocks were statistically significantly different. The average number of flower buds on long fruiting branches was highest in the cultivar ‛Buda’ on the rootstock ‛Myrobalan 29c’ (76.00) and lowest in the cultivars ‛Novosadska Rodna’ (37.53) and ‛NS-4’ (34.80) on the rootstock ‛Belošljiva’. The ‛Myrobalan 29c’ rootstock had a significant influence on generative potential of all tested cultivars. The results allow the conclusion that the rootstocks have a significant positive influence on the vigour and characteristics of the long fruiting branches of the tested cultivars.

Key words: adaptability, autochthonous ger m plasm, ‘Oblačinska’ sour cherry, breeding, Prunus armeniaca, trunk cross-sectional area, length and thickness of long fruiting branches, number of flower and vegetative buds

Title: The impact of bioregulators and biostimulator on the fruit quality of sweet and sour cherries

Authors: Biserka Milić, Nenad Magazin, Zoran Keserović, Maja Milović, Jelena Kalajdžić, Stefan Gligorić, Jelena Savićević

Download: PDF

Abstract: Bioregulators and biostimulators play a significant role in enhancing fruit set, weight and firmness in different tree fruit species. The aim of this study was to examine the effects of the products based on gibberellic acid (GA), 6-benzyladenine (BA), and α-naphthaleneacetic acid (NAA) on fruit set and fruit quality in the sweet and sour cherry cultivars ʻSkeena’ and ʻÉrdi Bötermö’. For sweet cherries, the treatments involved ʻOroGibbʼ (GA3 1.6 % + BA 1.6 % + B) and ʻGranPeraʼ (GA3 2% + P, K), at concentrations of 10 mg l-1 and 20 mg l-1 active ingredient (a.i.), applied at the flowering fading (BBCH 67) or when the fruit reached 60% of final size (BBCH 76). The following treatments were established: I (ʻOroGibbʼ at 10 mg l-1 a.i., applied at BBCH 67 stage); II (ʻOroGibbʼ at 20 mg l-1 a.i., applied at BBCH 67 stage); III (ʻGranPeraʼ at 10 mg l-1 a.i., applied at BBCH 67 stage); IV (ʻGranPeraʼ at 10 mg l-1 a.i., applied two times at BBCH 76 stage); V (ʻGranPeraʼ at 20 mg l-1 a.i., applied at BBCH 67 stage); VI (ʻGranPeraʼ at 20 mg l-1 a.i., applied two times at BBCH 76 stage). In addition to ʻOroGibbʼ and ʻGranPeraʼ, ʻFrutaFijaʼ (amino acids 4.5%; P2O5 13%; K2O 18%; B 0,5%; Fe 0.04%; Cu 0.01%) biostimulator was also used for sour cherry. The applied concentrations were 10 mg l-1 and 20 mg l-1 a.i., and time of application was at the end of flowering (BBCH 69) or/and when the fruit reached 60% of final size (BBCH 76). The following treatments were established: I (ʻOroGibbʼ at 10 mg l-1 a.i., applied at BBCH 69 and BBCH 76 stages); II (ʻOroGibbʼ at 20 mg l-1 a.i., applied at BBCH 69 and BBCH 76 stages); III (ʻGranPeraʼ at 10 mg l-1 a.i., applied at BBCH 69 and BBCH 76 stages); IV (ʻGranPeraʼ at 20 mg l-1 a.i., applied at BBCH 69 and BBCH 76 stages); V (ʻFrutaFijaʼ at 20 mg l-1 a.i., applied at BBCH 69 stage). Untreated trees of both fruit species were used as control. The highest fruit weight (11.6 g) and diameter (29.0 mm) of ʻSkeenaʼ were recorded in treatment VI. Applied treatments had no impact on fruit firmness, soluble solids content and acidity of ʻSkeenaʼ fruts. The highest fruit set of sour cherry cultivar ʻÉrdi Bötermö’ was recorded in the treatment I (27.4%), but only this treatment showed no significantly higher fruit weight and diameter compared to the control. Sour cherry fruits from treatment III exhibited significantly higher fruit firmness compared to the control, while the fruits from treatments I, II and III were characterized by a higher content of soluble solids and total acids.

Key words: stone fruit, GA3, BA, NAA, fruit set, fruit weight, SSC, total acidity

Title: BULL'S EYE ROT – A DISEASE OF STORED APPLE FRUIT

Authors: Jelena Vukotić, Vera Stojšin, Mila Grahovac, Mladen Petreš, Dragana Budakov, Milica Mihajlović, Jovana Hrustić, Brankica Pešić

Download: PDF

Abstract: Phytopathogenic fungi from the Neofabraea genus are one of the major causal agents of the postharvest decay of apple fruit as well as tree canker. In 2016, a disease caused by Neofabraea alba was detected for the first time in Serbia. Although the infection usually occurs during the growing season, the symptoms of rot appear several months later, during the storage period. The infected fruits develop necrosis and show the morphological characteristics of N. alba. The appearance of rot affects the quality of the fruit, with the intensity of the rot depending on the type of cold storage and the cultivars. The control of this disease in apple orchards is based on the use of fungicides. The use of synthetic fungicides is highly effective, but their use has led to problems such as environmental pollution, development of resistance and residual toxicity. Therefore, other bull's eye rot control strategies, such as application of biopesticides, have to be developed.

Key words: Malus domestica, Neofabraea spp., postharvest pathogens, frut rot

Title: EXAMINATION OF OXIDATIVE STABILITY AND ANTIOXIDANT ACTIVITY OF COLD-PRESSED APPLE SEED OILS

Authors: Miloš Purić, Aleksandra Stojićević, Aleksandar Ivković

Download: PDF

Abstract: After industrial processing of apples, about 25% of the apple pulp remains, containing potentially valuable by-products, such as apple seeds. This study investigated the oxidative stability and antioxidant activity of oils cold-pressed from the seeds of three apple cultivars: ‘Idared’, ‘Golden Delicious’, and ‘Šumatovka’. Peroxide number and conjugated dienes were determined as indicators of primary oxidation products in the obtained oils. Anisidine number and conjugated trienes were used as indicators of secondary oxidation products. The oxidative stability of the oil was assessed using the Rancimat method, with results presented as the induction period. Antioxidant activity was determined using the DPPH and ABTS methods. In general, the results indicate good oxidative stability in the examined cold-pressed apple seed oils. Additionally, the oil parameters differed significantly depending on the apple cultivar. The oil from ‘Idared’ seeds had the lowest peroxide number (2.8) and the lowest levels of conjugated dienes and trienes (1.95 and 0.39, respectively). The oil from ‘Golden Delicious’ seeds had the lowest anisidine number (0.61), the longest induction period (13.97 h), and the highest antioxidant activity (61.6 μmol TE kg-1 and 68.2 μmol TE kg-1). Among the examined oil samples, the oil from ‘Šumatovka’ seeds showed the least favorable results.

Key words: apple seeds, cultivar, cold-pressed oil, induction period, DPPH, ABTS