Mustafa Kemal Üniversitesi Tarım Bilimleri Dergisi 24 (Özel Sayı):179-187, 2019 (Mustafa Kemal University Journal of Agricultural Sciences 24 (Special Issue):179-187, 2019) e-ISSN: 2667-7733 http://dergipark.org.tr/mkutbd ARAŞTIRMA MAKALESİ RESEARCH ARTICLE The effect of different irrigation programs on chlorophyl content in watermelon Karpuzda farklı sulama programlarının klorofil içeriğine etkisi Gülşen DURAKTEKİN 1 , Yeşim BOZKURT ÇOLAK 1 Mete ÖZFİDANER 1 Alper BAYDAR 1 , Engin GÖNEN 1 1 Alata Horticultural Research Institute, Soil and Water Resources Research Unit, Mersin, Turkey. MAKALE BİLGİSİ / ARTICLE INFO Ö Z E T / A B S T R A C T Makale tarihçesi / Article history: Geliş tarihi /Received:09.10.2019 Kabul tarihi/Accepted:16.12.2019 Aims: This study was carried out to determine effect of different irrigation intervals and different irrigation levels on chlorophyll content (SPAD) of watermelon irrigated with a trickle system in 2017 growing seasons at the Alata Horticultural Research Institute, Tarsus Soil and Water Resources Location. Methods and Results: The cultivar Crimson Tide F1 was used in this research. Experimental design is randomized blocks with three replications. In the studies, the main issues from the three different irrigation intervals (4, 8 and 12 days); six different irrigation levels (TS (full irrigation): soil water deficit in the 90 cm within the four day intervals was replenished to the field capacity; KS75:75% of the water given to the TS subject, KS50:50% of the water given to the TS subject, PRD100: water applied to full irrigation, laterals operated alternately PRD75:in which 75% of water applied to full irrigation, laterals operated alternately, PRD50:in which 50% of water applied to full irrigation, laterals operated alternately ) created the sub-plots. The total amount of irrigation water applied to the subjects varied between 150-300 mm and the evapotranspiration values ranged between 379-486 mm. The effect of irrigation levels on yield was found differrent statistically significant. Significant linear relationships between chlorophyll content (SPAD) and yield were determined. Conclusions: As the applied irrigation water increased and irrigation interval decreased, chlorophyll values increased. Watermelon should be irrigated at chlorophyll content (SPAD) value between 54.00 for high yield. Significance and Impact of the Study: With the data obtained at the end of the project, it can be said that chlorophyll value can be used in irrigation programming to determine water stress by determining the optimum irrigation interval and irrigation application for watermelon. Keywords: Watermelon, irrigation intervals, irrigation level, chlorophyll content, partial rootzone drying.  Corresponding author: Gülşen DURAKTEKİN : gulsenduraktekin@gmail.com.tr Atıf / Citation: Duraktekin G, Bozkurt Çolak Y, Özfidaner M, Baydar A, Gönen E (2019) The effect of different irrigation programs on chlorophyl content in watermelon. MKU. Tar. Bil. Derg. 24 (Özel Sayı) :179-187 GİRİŞ Türkiye 4.01 milyon ton karpuz üretim hacmi ile Çin’den sonra 2. sırada yer almaktadır (Anonim, 2015). Yıllık karpuz üretiminde, Çukurova; 832 bin ton ile Türkiye’de ilk sırada olup üretiminin yaklaşık %89’u Çukurova bölgesinde gerçekleştirilmektedir (TÜİK, 2017). Karpuz bitkisinde yetiştiricilik, birim alana getirinin yüksek olması nedeni ile genellikle örtüaltında yapılmaktadır. (TÜİK, 2017). Sebze tarımında önemli bir yere sahip olan karpuz bitkisi susuzluktan olumsuz etkilenmektedir. Karpuzun gelişme hızının yüksek, yetişme döneminin kısa olması ve meyvede % 90–92 oranında su bulunması nedeniyle yüksek verim düzeyine ulaşmak için, sulanması gerektiği bilinmektedir (Miller, 2002). Karpuz, gelişim dönemi boyunca fazla buharlaşma ve düşük yağış nedeniyle sık