Field experiments were carried out during the period from 2013 to 2017 in the winter season at the experimental farm, Faculty of Agriculture, South Valley University, Qena, Egypt. Improvement yield and its attributes in Edkawy local cultivar via mass selection were done for three cycles. The unselected base population (C0) and selected populations (C1, C2, and C3) evaluated under two different water availability, favorable normal condition, and drought. The combined analysis of variance showed that significant differences between unselected and selected populations as well as highly significant among three cycles populations were detected all studied traits. Average fruit weight, number of flowers per plant, fruit yield per plant, number of cluster per plant, number of fruit per plant, number of branches per plant, fruit set percentage, and plant height have significantly increased a response to mass selection under unfavorable conditions. These increasing values for average fruit weight were 3.24, 6.90, and 12.09% in C1, C2, and C3, respectively. Furthermore, there was a significant increase in the number of fruits per plant in the first (2.45%), second (9.48%) and the third (13.72%) cycles under drought conditions. Fruits yield per plant was increased by 4.70, 12.44 and 21.40% for unselected and selected population, respectively. There was positive and highly significant correlation among all studied traits. In the respect to base populations under water stress treatments, results revealed that the use of mass selection for improvement yield and its components of tomato cv. Edkawy appeared to be increasing significantly for all studied traits.

 

Key words: Drought, yield attributes, Edkawy, mass selection, tomato.