Mathematical modeling of crop water production functions for sugar beet

Abstract

Crop water production functions, which describe the relationship between yield and water use, are of great importance in determining the economic value of irrigation, identifying different irrigation strategies and determining optimum irrigation levels. The main objective of this study was to evaluate the performance of Stewart, Jensen, Minhas, Blank and Rao functions in predicting root yield in sugar beet. Field studies were carried out in 2019 and 2020 in Bursa Yeni & scedil;ehir Vocational School Production Area. Water stress sensitivity indices of crop water production functions were determined using ET and yield values in the first year. Root yield values simulated with crop water production functions were compared with root yield values measured in the field in 2020. Sensitivity indices of sugar beet to water at four different growth stages were determined using five different crop water production models. Considering the sensitivity indices of sugar beet to water in four different growth periods, it was determined that the yield formation period (Y) was the most sensitive to water. Yield formation (Y) period was followed by vegetative (V) and establishment (E) periods. The least water-sensitive period of sugar beet was the ripening (R) period. Jensen and Minhas models were recommended when the sensitivity indices to water stress calculated for four different growth stages of sugar beet were compared.