Ammar Abbas^1*, Fadi Kazngi¹, Lama Kafa¹, Mohammad Nizam¹ and Alaa Hafi¹

1 General Commission for Scientific Agricultural Research, Lattakia Research Center, Syria.
(*Corresponding author: Ammar Abbas, Email: ammarabbas1984@hotmail.com , Tel: 0991978115).

Received: 3/ 9/ 2025     Accepted: 9/ 12/ 2025

This research aims to explain the importance of using the ET0 calculator model in estimating the evapotranspiration values for sunflower crop cultivar vulgaris which is adopted for coastal region. ET0calculator is characterized by the accuracy of evapotranspiration values, according to Bennman Monteith modified equation depending on (FAO n56) publication which is also based on a number of climatic factors include: maximum, minimum and average temperatures, relative humidity, wind speed and sunshine. The most affecting climatic factors were identified (maximum, minimum and average temperatures, relative humidity, wind speed and sunshine) by studying the simple correlation between the climatic factors and ET0 values, then the multiple correlation was studied. The evapotranspiration values varied according to the phonological phase, and the vegetative growth phase had the highest values. In general, the simple correlation showed low to moderate values through the phonological stages whereas the values of multiple connection were medium to high in general. The highest of multiple connection values were between evapotranspiration with relative humidity, temperature and sun shine (R 0.96) and the lowest values between evapotranspiration with both relative humidity and wind speed (0.43).

Keywords: Et0 Calculator ,sunflower , phenology, correlation.

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