TERMAL REQUIRENMENT AND AGRONOMIC TRAITS OF COMERCIAL AND EXPERIMENTAL SUNFLOWER CULTIVARS AT DEPRESS?O CENTRAL OF RIO GRANDE DO SUL, BRAZIL

摘要

The utilization of methods based on thermal requirenment of sunflower permits to evaluate the possibility of cultivars adaptation to different áreas, as well as define differences among these cultivars, preview plant maturity and realize a better choice of planting date. With the objective of determining thermal exigence of emergence-flowering subperiod of comercial and experimental sunflower cultivars and evaluate these cultivars in relation to grain yield, oil content and other agronomic characteristics, two experiments were carried out during 1991/92, at Eldorado do Sul, RS. In experiment 1 (Final Trial) 11 cultivars were tested, and in experiment 2 (Intermediary Trial), 14 cultivars. In the first experiment it was possible to distinguish four groups of cultivars in relation to emergence-flowering subperiod duration and in the second trial three different group of cultivars were observed for the same parameter. In experiment 1. the varieties named ICI EX 9001, S 430, DK 180. BR-G 89 V2000, Contisol 711, GR 18 and VIKI compounded the group with the highest grain yield, while in experiment 2, DK 180, Pioneer XF 3617, Pioneer 91012 and Cargill 9102 were in a group with the highest grain yield.