A. Aytekin Polat

Determining total phenolic content and total antioxidant capacity of loquat cultivars grown in Hatay

Several fruit characteristics of five loquat (Eriobotrya japonica (Thunb.) Lindl.) cultivars/selections grown in Dörtyol, Hatay, Turkey were investigated in 2008. The cultivars/selections included ‘Baduna 5’, Güzelyurt 1, ‘Hafif Çukurgöbek’, ‘Ottaviani,’ and Type 1. The characteristics evaluated included fruit weight, width, length, seed number and weight, flesh/seed ratio, total soluble solids (TSS), pH, acidity, total phenolic (TP) content, and total antioxidant capacity (TAC), determined by the ferric reducing antioxidant power (FRAP) assay. The analyses were conducted by three replicates, with 30 fruits in each replicate. The results indicated that there were significant differences among the cultivars, for all the traits tested. For example, ‘Hafif Çukurgöbek’ and ‘Ottaviani’ had smaller fruits than others, although ‘Hafif Çukurgöbek’ had heavier seeds. The flesh/seed ratio was the highest in Type 1, while ‘Hafif Çukurgöbek’ had the highest pH and high soluble solids. ‘Baduna 5’ and ‘Hafif Çukurgöbek’ had the highest acidity. The TP ranged from 129 (‘Baduna 5’) to 578 (‘Hafif Çukurgöbek’) mg gallic acid equivalent (GAE)/kg fresh fruit (fw). ‘Hafif Çukurgöbek’ also had the highest FRAP mean (12.1 mmol Trolox Equivalent (TE)/kg fw). The results suggest that loquat cultivars have a variable range of TP content and a relatively high total antioxidant capacity, which is crucial for human health.

Determination of productivity and fruit set ratios of various loquat (Eriobotrya japonica) cultivars under Mediterranean conditions

Abstract This study was conducted to determine fruit set ratios and productivity of four loquat (Eriobotrya japonica) cultivars, ‘Gold Nugget’, ‘Kanro’, ‘Baffico’, and ‘Dr. Trabut’ on the coast of the Mediterranean region of Turkey between 2001 and 2003. Elevation of the experimental site was c. 158m, with an average annual temperature of 19°C and annual rainfall of 556 mm (average of 1983–2003). To determine fruit set, a branch was randomly selected from all four directions on each tree. Approximately 250–300 flower buds were counted before the blossom at each of these selected branches making a total of c. 1000–1200 flower buds on each tree. Percent blossom ratios, % initial fruit set, and % final fruit set were determined during the experimental period. Furthermore, productivity of the cultivars was calculated by the proportion of the total flower buds to the final fruit amount. The relation between minimum, maximum, and average temperature values as well as relative humidity and precipitation between October and February, which covers blossom periods and fruit set ratios, were also examined by correlation. Our results showed that the highest rates for the above‐mentioned properties were taken in 2002 except % blossom, the highest rates were for ‘Gold Nugget’ for the other three properties. According to 3‐year averages, ‘Gold Nugget’ showed higher rates on initial fruit set, final fruit set, and productivity (12.39%, 11.03%, and 10.22%, respectively). Percent initial fruit set was between 6.98% and 9.70%, % final fruit set was between 5.66% and 7.55%, and productivity was between 5.33% and 6.94% for the other three cultivars.

Correlations among Important Fruit Quality and Plant Characteristics of Some Fig Genotypes

Experiments were carried to determine correlations of important fruit and plant characteristics using 30 fig genotypes. The correlation coefficients between these traits were calculated using SAS program. Fruit weight, fruit diameter, fruit length, neck length, ostiolium width, abscission of the stalk from the twig, ease of peeling, fruit skin cracks, thickness of the fruit skin, texture of skin, fruit ribs, fruit internal cavity, TSS (total soluble solids), pH, acidity, TSS/acidity, trunk diameter, shoot length, yield per tree were traits examined in the study. According to five-year data, fruit weight was found to have positive correlation by fruit diameter (r = 0.92; P < 0.01), fruit length (r = 0.81; P < 0.01), neck length (r = 0.35; P < 0.01), ostiolium width (r = 0.23; P < 0.01), trunk diameter (r = 0.26; P < 0.01), fruit skin cracks (r = 0.26; P < 0.01) and negative correlation by TSS (r = -0.26; P < 0.01) and fruit ribs (r = -0.21; P < 0.01). Relations between some traits such as ostiolium width, abscission of the stalk from the twig, ease of peeling, fruit skin cracks, texture of skin and fruit ribs are deviated based on the years. Some relationships between fig fruit characteristics exist, which may help researchers to solve some problems such as ostiolium width and fruit skin cracking. These studies may contribute to producing fruit with a good quality and help to evaluate new cultivars.

Yield and Fruit Characteristics of Various Apricot Cultivars under Subtropical Climate Conditions of the Mediterranean Region in Turkey

Seven apricot cultivars (“Beliana,” “Canino,” “Precoce de Colomer,” “Feriana,” “Rouge de Sernhac,” “Tokaloglu,” and “Macar”) were evaluated at the experimental orchard of the Department of Horticulture, Faculty of Agriculture, Mustafa Kemal University, Hatay, Turkey. Phenological and pomological characteristics such as flowering period, average fruit weight, yield, fruit dimensions, flesh/seed ratio, acidity, and total soluble solids (TSSs) were examined. In addition, yield parameters of the cultivars were evaluated. Over four years, the highest average fruit weight was obtained from “Rouge de Sernhac” (37.9 g), while “Feriana” had the lowest (30.9 g). The flesh/seed ratio was the highest in the “Canino” (16.8). “Canino” had the highest TSS content with 14.5%, whereas “Beliana” had the lowest TSS value with 10.6%. “Beliana” and “Feriana” ripened the earliest (May 20) while “Precoce de Colomer” ripened latest (June 7). The average yield was highest on “Rouge de Sernhac” (41.2 kg/tree). “Beliana” and “Feriana” cultivars are recommended for precocity, and “Rouge de Sernhac” and “Tokaloglu” for middle season in Dortyol, Turkey.