The main objective of this study conducted in Turkey in 1998 and 1999, was to ascertain the correct irrigation scheduling of watermelon (Citrullus vulgaris) under adequate soil water supply during whole growing season, and under limited soil water supply at different seasonal combinations. The yield and the yield components, the sensitive periods to soil water deficits and the yield response factors were determined under the condition of which 0, 25, 50, 75 and 100% of water requirement was supplied during the whole growing season and also during individual growing periods, namely, early vegetative growth, late vegetative growth, total vegetative growth, flowering and fruit growth. The highest fruit yield was obtained from the plots where irrigation water was adequately applied during the total growing season. Flowering was the most sensitive period to water deficits. The yield response factors (k(y)) which relates relative yield decrease to relative evapotranspiration deficit were found to he 1.27 for the whole growing season and 0.68, 0.63, 0.50, 0.47, 0.29 for flowering, fruit growth, late vegetative, total vegetative, early vegetative periods, respectively. (C) 2003 Elsevier B.V. All rights reserved.
