Comparison of open field and protected cultivation of five early table grape cultivars under Mediterranean conditions

The production of grapes for early table consumption is becoming more popular in the Mediterranean region of Turkey. In this study, the cultivation of 5 early table grape cultivars ('Ergin cekirdeksizi', 'Uslu', 'Yalova incisi', 'Cardinal', and 'Perlette') in the open field and under protected cultivation were compared in 2004-2005 and 2005-2006 seasons. For the protected culture, the grapevines were covered on 23 February 2004 and 24 February 2005. The phenologic observations, pomologic analyses, yield variables, and primary shoot growth were determined. When compared to open field production, protected production led to 15-18 days earliness. 'Uslu' was the earliest cultivar in both open field and protected cultivation. The cluster weight, cluster width, and cluster length of cultivars did not vary between the different production treatments. Total soluble solids (TSS) and pH values of both of the production types were similar. For 'Yalova incisi' and 'Cardinal', the yield in open field production was higher than that in protected cultivation. In protected cultivation, the effect of production sites on shoot development was greater than it was in the open field. The highest primary shoot length was observed in 'Uslu' in both treatments.