Ozmen, Selcuk;Kanber, Riza;Sari, Nebahat;Unlu, Mustafa

Univ Cukurova, Dept Irrigat & Drainage Engn, TR-01330 Adana, Turkey;Univ Duzce, Dept Biosyst Engn, TR-81620 Duzce, Turkey;Univ Cukurova, Dept Hort, TR-01330 Adana, Turkey

deficit drip irrigation;yield;evapotranspiration;grafted watermelon;nitrogen;fruit quality

The aim of this study is to determine the effects of deficit irrigation on nitrogen consumption, yield, and quality in grafted and ungrafted watermelon. The study was conducted in cukurova region, Eastern Mediterranean, Turkey, between 2006 and 2008, and employed 3 irrigation rates (full irrigation (I-100) with no stress, moderate irrigation (DI70), and low irrigation (DI50); DI70 and DI50 were considered deficit irrigation) on grafted (CTJ, Crimson Tide+Jumbo) and the ungrafted (CT, Crimson Tide) watermelon. The amount of irrigation water (IR) applied to the study plots were calculated based on cumulative pan evaporation that occurred during the irrigation intervals. Nitrogen consumption was 16% lower in CTJ plants than in CT plants. On the other hand, consumption of nitrogen was 28% higher in DI50 plants than in DI70 plants while it was 23% higher in DI50 plants than in I-100 plants. By grafting, the average amount of nitrogen content in seeds, pulps and peels for CTJ was 30, 43 and 56% more than those of CT, respectively. The yield and the quality were not significantly affected by the deficit irrigation. In this respect, grafting of watermelon gave higher yield, but, it had a slight effect on fruit quality. The highest yield values of 16.90 and 19.32 kg plant(-1) in 2008 were obtained with I-100 and in CTJ plants, respectively. However, DI50 treatment could be taken into account for the development of reduced irrigation strategies in semiarid regions where irrigation water supplies are limited. Additionally, the yield increased by applying CTJ treatment to the watermelon production.