ABSTRACT
Research was conducted under field conditions in the Piracicaba, SP, Brazil, to evaluate potato (Solanum tuberosum L.) "Monalisa" subjected to water deficit at different development stages. The experimental design consisted of completely randomized blocks, with eight treatments and four replications. Treatments consisted i of applying water stress at one or more development stages, starting 15 days after emergancy. Tuber formation stage, the most sensible one to water stress, had a 48.7% yield reduction in relation to the control. Water stress applied to the stages of, tuber initiation and tuber filling provided a sharp (65.4%) yield reduction. When applied to the three stages, water stress provided a drastic (70.5%) yield reduction. Water deficit also affected the number of tubers per plant and the tuber sizes.
Key words:
Solanum tuberosum; evapotranspiration; water balance