Effects of Pre-Harvest Deficit and Excess Irrigation Water on Vine Water Relations, Productivity and Quality of Crimson Seedless Table Grapes | ||
| Journal of Plant Production | ||
| Article 13, Volume 8, Issue 1, January 2017, Pages 83-92 PDF (445.39 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jpp.2017.37819 | ||
| Author | ||
| D. O. El-Ansary* | ||
| Department of Pomology, Faculty of Agriculture (El-Shatby), University of Alexandria, 21545, Egypt | ||
| Abstract | ||
| This research investigated the effects of pre-harvest deficit and excess irrigation water on vine water relations, productivity and quality of Crimson Seedless table grapes. In 2011 and 2012 seasons, five irrigation regimes were imposed for seven weeks from veraison to harvest based on actual crop evapotranspiration (ETc): 80 % ETc (moderate deficit irrigation), 90 % ETc (slight deficit irrigation), 100 % ETc (standard control irrigation), 110 % ETc (slight excess irrigation) and 120 % ETc (moderate excess irrigation). Results showed that soil volumetric water content and midday leaf water potential responded to the irrigation treatments and there were very significant relationships among them. Vine yield was not influenced by irrigation treatments in 2011, but 80 % ETc irrigated vines had significantly lower yield (20.9 kg /vine) than control (23.6 kg/vine) in 2012. Pre-harvest water use efficiency (WUE) significantly decreased with increased irrigation level, while no variations were found in the seasonal WUE. 80 % ETc irrigated vines had the lowest significant berry diameter values as compared with control and other treatments in both seasons. Berry weight of 80 % ETc irrigated vines was only significantly lower than berries of 120 ETc treatment in 2011, but was lower than berries of 100 ETc, 110 ETC, and 120 ETc vines in 2012. Berry firmness was negatively affected by decreasing irrigation level as it was significantly lower in 80% ETc irrigated vines as compared with control and other treatments. Juice total soluble solids percent was significantly highest in deficit irrigation treatments as compared with control and excess irrigation treatments in both seasons, except for 90 % ETc treatment where it was not significantly different from control in 2012. Titratable acidity percent in juice decreased with decreasing irrigating level and was significantly lowest in 80 % ETc irrigated vines as compared with control and other treatments. TSS to Acid ratio in juice was significantly highest in 80 % ETc irrigation treatment, followed by 90% ETc and control treatments, and was lowest in excess irrigation treatments. Berry skin color characteristics data of lightness (L*), chroma (C*), and hue angle (h°) decreased with increasing irrigation level and were significantly lowest in deficit irrigation treatments as compared with excess irrigation treatments and control in both seasons, except for lightness values in 2011. Berry skin color index for red grapes (CIRG) increased significantly in deficit irrigation treatments, followed by control, and was lowest in excess irrigation treatments. It is concluded that 90 % ETc irrigation treatment maintained vine yield and had positive effects on berry commercial quality characteristics. | ||
| Keywords | ||
| grape; veraison; seasonal; soil volumetric water content; leaf water potential; water use efficiency; TSS to Acid ratio; skin color; color index for red grapes (CIRG) | ||
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