Fruit set of Turkish quince cv. 'Ekmek' (Cydonia oblanga Mill.) under open-pollination conditions.
Turkey is one of the motherlands and native spreading areas of quince (Ozbek, 1978; Tekintas et al. 1991). It is possible to meet to quince trees in all temperate regions of Turkey. The cultivar 'Ekmek', which is apparently self-fruitful (Ozbek, 1978), is one of quince cultivars desired for Turkish markets.
Quince flowers are borne terminally on current season's growth. Since flowering occurs in late spring, spring frosts are usually not a serious problem. The quince is a decidious thornless shrub or small tree, and quince fruits ripen late in autumn. The bright yellow colored fruits can be eated fresh if they were fully ripened. The fruit flesh is dry and mealy, usually made into jam, jelly, etc. The pink or white colored flowers occur solitary at the end of short twigs. Fruits can be with light golden-yellow, green or orange colors, and they are usually pear, round or apple shaped. The fruit pulp with gritty cells is firm and aromatic. As quince fruits ripen, their colors turn from green to yellow.
Flowering period was in May or June after the leaves. Since quince cultivars are selffertile, both cool and hot climates make possible a good fruit set (Ozbek, 1978). As pollinators, honey bees are valuable on pollination of quince flowers (Benedek et al. 2001). Although quince is apparently self-fruitful, factors affecting pollination and bee activity such as adverse weather conditions, frosts, wind and low temperatures, rain, water stress, irrigation treatments, high relative humidity in the late spring can cause low fruit set, high fruit drops and low yield. The optimal fruit set was reported as 20-25% for quinces (Benedek et al. 2001).
With micro-climate structure, Van city located in eastern Anatolia region of Turkey has suitable climatic conditions for quince culture. Quince growing with standard cultivars is not common in Van. The preliminary studies performed on phenological, pomological and yield characteristics of quinces in Van city revealed successfull results (Koyuncu et al. 1996).
The yield of quince trees is closely related to fruit set and fruit drops. Regular fruit set and low fruit drop is among the desired characteristics for quince growing. The existing references report a limited information on fruit set and drops for quinces (Tekintas et al. 1991; Ercan et al. 1992). This research aimed to determine the percentages of fruit set and fruit drops in Turkish quince cultivar 'Ekmek' grown in Van city.
MATERIALS AND METHODS
The study was performed in 13-year-old trees belonging to Turkish quince cultivar 'Ekmek' (Cydonia oblonga Mill.) during 2004-2005. At full bloom period, the opened flowers were separately counted in three different branches in both 2004 and 2005. Flower counts per branch at full bloom stage were recorded on 27 May in the first year, and on 23 May in the second year. Flower numbers were determined in three different branches of each tree. Subsequent to full bloom period, fruitlets or fruits were counted in 16 different dates from 03 June to 10 November in the first year, and in 24 different dates from 03 June to 11 November in the second year. After flowering period, fruit set and fruit drops proceeded under orchard conditions. The trees were subjected to open-pollination conditions. The three single-tree replicates of the cultivar were used to record flower counts, fruit sets and fruitlets/fruit drops. The final fruit set was expressed as the percentage of fruits per total flowers opened (Williams, 1970; Alburquerque et al. 2003).
RESULTS AND DISCUSSIONS
In full bloom period of the first and second year, the mean flower numbers counted per branch in the cultivar were 78.8 and 136.3, respectively (Table 1), and therefore the mean flower number per branch was higher than that of the first year. In addition, full bloom period of the first year was a few days later than that of the second year. In this research, changes in fruit set and fruit drops after full bloom period were studied in 16 different dates in the first year and in 24 different dates in the second year.
In the first year, the numbers of fruitlets per branch in the first observation date (03 June) subsequent to the initial fruit set were counted as 132.6. In this date, fruit set percentage by flower number counted in full bloom period were 97.3%. With higher fruitlets drops, the dates of 14 June and 25 June was remarkable periods. Therefore, fruit set percentages highly decreased in these dates. The drops continued until 15 July when the fruit set percentage was 12.8%. After this date, fruit set percentage did not vary until harvest date (10 November). Thus, the final fruit set under open-pollination conditions in the first year resulted in 12.3% (Table 2).
In the second year, the numbers of fruitlets per branch in the first observation date (03 June) subsequent to the initial fruit set were determined as 70.0. In this date, fruit set percentage by flower number counted in full bloom period were 88.9%. As observed in the first year, three weeks after the first observation date, high fruitlets drops occurred. The drops continued until 24 June when the fruit set percentage was 15.2%. After this date, fruit set percentage decreased by 8.6% in early September. Thus, the final fruit set of the second year resulted in 12.3% under open-pollination conditions (Table 3).
The climatic conditions Van city is suitable for quince growing, and the yield is not usually influenced by late spring frosts. In Van city, late spring frosts occur in late April-early May. Therefore, quince trees were not influenced by late spring frosts in 2004 and 2005.
Benedek et al. (2001) recorded that final fruit set varied from 10.6% to 31.6% depending on the number of honeybees visiting to flowers. Kaufmane and Rumpunen (2002) reported that fruit set percentages of Japanese quince (Chaenomeles japonica) belonging to Rosaceae varied from 1% to 11%, and observed that its flowering period differed by years. On the other hand, the honeybee pollination can influence the fertilisation in the garden Investigating honeybee pollination in six quince cultivars in Hungary. Benedek et al. (2001) reported that the majority (51.6 % in average for three years) of honeybees visiting the flowers tended to collect pollen, 19.9% of honeybees gathered only nectar, and the rest (28.5%) exhibited a mixed foraging behaviour. Also, they stated that complete bee limitation during pollination period resulted in no yield, and partial bee limitation affected by at least 60-70% the final fruit set, and therefore a number of 4-5 or 8-10 honeybees should visit to one flower per day to reach the optimal fruit set wihich is 20-25% for quince.
At the end of this study, the final fruit set percentages for 'Ekmek' cv. under openpollination conditions without taking into consideration the bee activity in the garden were recorded as 12.3% in 2004 and 8.6% in 2005. These percentages were lower than those of the optimal fruit set which is reported as 20-25% for quinces, and they were similar to some findings reported by Benedek et al. (2001). The study suggested that final fruit set percentages can be improved by using a controlled bee activity in this cultivar.
(1.) Alburquerque, N., Burgos, L. and Egea , J.2003. Apricot flower development and abscission related to chilling, irrigation and type of shoots. Scientia Horticulturae 98:265-276.
(2.) Benedek, P., Szabo, T. and Nyeki, J. 2001. New results on the bee pollination of quince (Cydonia oblanga Mill.). Acta Horticulturae 561:243-248.
(3.) Ercan, N., Ozvardar, S. , Gonulsen, N., Baldiran , E. , Onal , K. and Karabiyik, N. 1992. Ege bolgesine uygun ayva cesitlerinin saptanmasi. Proceedings of Turkish Hort. Cong. : 527-529, Bornova, Izmir.
(4.) Kaufmane, E. and Rumpunen, K. 2002. Pollination, polen tube growth and fertilization in Chaenomeles japonica (Japanese quince). Scientia Horticulturae 94:257-271.
(5.) Koyuncu, F., Yilmaz, H. and Koyuncu, M. A. 1999. Ekmek Ayvasinin Van Ekolojik Kosullarinda Bazi Agac ve Meyve Ozelliklerinin Belirlenmesi Uzerine Bir Arastirma. YYU, Ziraat Fak. Tarim Bilimleri Dergisi, 9 (1):37-39.
(6.) Ozbek, S., 1978. Ozel Meyvecilik. C.U. Z.F. Yayinlari, No:28, pp486, Adana.
(7.) Tekintas, F. E., Cangi ,R. and Koyuncu, M.A.1991. Van ve Yoresinde Yetistirilen Mahalli Ayva Cesitlerinin Fenolojik ve Pomolojik Ozelliklerinin Belirlenmesi Uzerinde Bir Arastirma. Y.Y.U.Z.F. Dergisi, 1(2):56-67.
(8.) Williams, R.R., 1970. Factors affecting pollination in fruit trees. Edited by: L.C. Luckwill and C.V. Cutting, Physiology of Tree Crops. Academic Press, London : 193-207.
Corresponding author: Dr. Mehmet Fikret Balta, Department of Horticulture, Faculty of Agriculture, University of Yuzuncu Yil, 65080 Van, Turkey , E-mail: email@example.com; firstname.lastname@example.org
M. Fikret Balta and F. Muradoglu Yuzuncu Yil University , Faculty of Agriculture, Department of Horticulture, 65080-Van. Turkey
Table--1 : The mean flower number per branch in full blooming period in Turkish quince cultivar 'Ekmek' grown under ecological conditions of Van during 2004 and 2005. Year Full bloom date The mean number of flower per branch 2004 27 May 78.8 2005 23 May 136.3 Mean 107.6 Table--2 : Changes in fruit set and fruit drops after full bloom period in Turkish quince cultivar 'Ekmek' grown under ecological conditions of Van (2004) Dates Periods per branch NFS FS % by FB 03 June FL 132.6 97.3 14 June SF 77.3 56.7 25 Jun F 35.0 25.7 05 July F 21.4 15.7 15 July F 17.4 12.8 26 July F 16.9 12.4 06 August F 16.8 12.3 16 August F 16.8 12.3 26 August F 16.8 12.3 06 September F 16.8 12.3 16 September F 16.8 12.3 20 September F 16.8 12.3 07 October F 16.8 12.3 19 October F 16.8 12.3 30 October F 16.8 12.3 10 November F 16.8 12.3 FL: Fruitlets after fertilisation, SM: Small fruit period, F: Fruit period, NFS: The mean number of fruit set per branch, FB: Full bloom period, FS: Fruit set. Table--3: Changes in fruit set and fruit drops after full bloom period in Turkish quince cultivar 'Ekmek' grown under ecological conditions of Van (2005) Dates Periods Per branch NFS FS % by FB 03 June FL 70.0 88.9 10 June SF 49.2 62.4 17 June F 16.8 21.3 24 June F 12.0 15.2 01 July F 11.6 14.7 08 July F 11.1 14.1 15 July F 10.9 13.8 22 July F 10.1 12.8 29 July F 10.1 12.8 05 August F 10.1 12.8 12 August F 10.1 12.8 19 August F 9.1 11.5 26 August F 8.8 11.2 02 September F 7.6 9.6 09 September F 6.8 8.6 16 September F 6.8 8.6 23 September F 6.8 8.6 30 September F 6.8 8.6 07 October F 6.8 8.6 14 October F 6.8 8.6 21 October F 6.8 8.6 28 October F 6.8 8.6 04 November F 6.8 8.6 11 November F 6.8 8.6 FL: Fruitlets after fertilisation, SM: Small fruit period, F: Fruit period, NFS: The mean number of fruit set per branch, FB: Full bloom period, FS: Fruit set
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|Author:||Balta, M. Fikret; Muradoglu, F.|
|Publication:||Bio Science Research Bulletin -Biological Sciences|
|Date:||Jul 1, 2006|
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