Turan Hakan Demirkeser

Storage life of non-astringent persimmons grown in the eastern Mediterranean.

Abstract The storage life of the non-astringent persimmon cultivars ‘Fuyu’, ‘Jiro’, ‘Amankaki’ and ‘Hana Fuyu’ grown in the eastern Mediterranean region has been studied. Persimmon fruit were harvested at commercial maturity and stored at 0°C and 85–90% relative humidity. Neither chilling injury nor fungal decay were observed in ‘Fuyu’, ‘Jiro’ and ‘Amankaki’ over 150 days or in ‘Hana Fuyu’ over 120 days. Weight loss exceeded 10% in ‘Fuyu’ and ‘Amankaki’ fruit after 150 days and in ‘Jiro’ after 120 days. During storage, fruit softened and skin colour became darker (lower L* values) and deep orange-red (lower hue angle values) in all cultivars. Total soluble solids (TSS) content and titratable acidity did not change significantly. Results confirm that ‘Fuyu’ and ‘Jiro’ can be stored under these conditions for up to 150 days and ‘Amankaki’ and ‘Hana Fuyu’ for up to 120 days.

Comparison of several plant nutrient elements in conventionally and organically grown citrus orchards

Organic citrus production has been increasing recently in Turkey. In this study, we compared several nutri-elements concentrations of organically (ORG) and conventionally (CON) grown citrus orchards in the Mediterranean region of Turkey. The samples included Satsuma mandarins (Citrus unshiu L.) and Washington navel and Valencia oranges (Citrus sinensis (L.) Osbeck), which were grafted on sour orange (Citrus aurantium L.). In 1996, 58 citrus orchards were sampled and 48 of them used for analyses. Three years after the first sampling, some orchards switched from CON to ORG production. Sampling was repeated in 2007 and included 31 samples from CON and 30 samples from orchards that switched to ORG after the 1996 samples were taken. Concentrations of N, P, K, Ca, Mg, Na, B, Cu, Fe, Mn and Zn were determined using the samples from 1996; with the exception of B, no significant differences were observed. Analysis of the samples from 2007 indicated statistically significant differences between the two groups for concentrations of N, K, Mg, B and Mn. The means of both samples were subjected to principle component analysis (PCA); the results indicated that, after several years of ORG culture, the two groups were clearly separated. The variables highly correlated with PC1 were Na, Fe and Ca, while P, K, Mn and Mg were correlated by PC2. B, Fe and Zn correlated by PC3. Several trace elements (Pb, Cu, Fe, Mn, Ni and Zn) from five randomly chosen soil samples from both CON and ORG growing groups were determined, and the results indicated that the mean concentrations for the two groups were similar for most of the elements (Pb, Cu, Fe and Ni). Our results shed light on the optimization of plant nutrient programs in organic citrus production.

Seasonal Carbohydrate Changes in the Leaves of Some Satsuma Cultivars on Different Rootstocks

The seasonal changes of carbohydrate content were monitored in the leaves of ‘Okitsu’, ‘Clausellina’, and ‘Silverhill’ satsuma cultivars budded on the sour orange (Citrus aurantium L. var. Yerli), Carrizo and Troyer citranges (Poncirus trifoliata Raf. x Citrus sinensis Osb. var. Troyer and Carrizo) during the 2010 and 2011 seasons. The seasonal changing trends of leaf soluble sugar contents of 3 satsuma cultivars budded on different rootstocks were similar. The sucrose was the most abundant soluble sugar. Carbohydrate contents had a maximum level at dormant period, and remained at low level during summer. In this period, the sharp decrease in leaf total carbohydrate concentration of ‘Okitsu’, ‘Clausellina’ and ‘Silverhill’ occurred in April with a rate of 27.9%, 22.6% and 21.0%, respectively. Accumulation of carbohydrate in leaves generally started after mid summer and continued until the end of year. The rootstocks were found to be not significant for total soluble sugar, starch and total carbohydrate concentration in most of the months. The cultivars had a significant effect on carbohydrate fractions of leaves compared to rootstocks. The scion-rootstock combination was significant on total carbohydrate concentration of leaves in all months investigated.

Fremont ve Nova mandarin çeşitlerinin meyve gelişim sürecindeki kalite parametrelerindeki değişimler ve derim olumu

Bu calismanin amaci, Dortyol kosullarinda yetistirilen Fremont ve Nova mandarin cesitlerinin meyve kalitesinde gorulen degisimlerin ve derim zamaninin belirlenmesidir. Bu arastirmada yerli turunc anaci uzerine asili Fremont ve Nova mandarin cesitlerinin meyveleri kullanilmistir. Meyve gelisim surecinde secilen agaclardan Haziran dokumunden olgunlasincaya kadar meyve ornekleri alinmaya baslamis ve alinan meyvelerde her seferinde meyve eni (mm) ve boyu (mm), meyve agirligi (g), meyve kabuk rengi L* ve h o degeri, usare miktari (%), suda cozunebilir toplam kuru madde miktari (SCKM, %), titre edilebilir asit icerigi (TEA, %), SCKM/TEA orani ve meyve suyu pH degeri olculmustur. Bulgularimiza gore, Dortyol kosullarinda yetistirilen Fremont ve Nova mandarin cesitleri icin Kasim ayinin son haftasi ile Aralik ayinin ilk haftasi (ciceklenmeden itibaren 200-215. gunler) SCKM/TEA orani 8’in uzerinde ve renklenme ( ho degeri 80-90 arasinda) yeterli seviyede olup, en uygun derim olum zamani olarak saptanmistir.

DÖRTYOL VE SAMANDAĞ (HATAY)' DA YETİŞTİRİLEN VALENCIA LATE PORTAKALLARININ SOĞUKTA MUHAFAZASI SIRASINDA KALİTE DEĞİŞİMLERİ

Bu calismanin amaci, Dortyol ve Samandag yorelerinde yetistirilen Valencia Late portakallarinin sogukta muhafazasi sirasinda meyve kalitesinde gorulen degisimlerin belirlenmesidir. Arastirmada, 7 x 7 m araliklarla tesis edilmis Yerli turunc anaci uzerine asili Valencia Late portakali meyveleri kullanilmistir. Valencia Late portakallari 4 ve 6°C’lerde ve %85-90 oransal nemde ayda bir analizlenmek uzere 6 ay sureyle muhafaza edilmislerdir. Muhafaza sirasinda meyvelerde meydana gelen fiziksel ve kimyasal degisimler (agirlik kayiplari, usare, yesil kapsullu meyve orani, suda cozunebilir toplam kuru madde, pH, titre edilebilir asit, meyve kabuk rengi L* ve hue degeri) ile mantarsal ve fizyolojik bozulmalar incelenmistir. Dortyol kosullarinda yetistirilen Valencia Late portakallarinin 4°C sicaklik ve %85-90 oransal nemde 4 ay, 6°C sicaklik ve %85-90 oransal nemde ise 3 ay depolanabilecegi saptanmistir. Samandag kosullarinda yetistirilenlerin ise 4°C ve 6°C sicaklik ve %85-90 oransal nemde 3 ay kalitelerinden cok fazla bir sey kaybetmeden depolanabilecegi saptanmistir.