RESPONSE OF SUNFLOWER PLANTS TO 2 SOWING PERIODS AND TO 2 FERTILIZATION LEVELS .2. PLANT CHARACTERISTICS ASSOCIATED WITH THE SUNFLOWER HARVEST

With the objective of identifying possible interactions among plant de nsity, planting date and soil fertility as well to assess their effect s on agronomic traits associated with the sunflower harvest, an experi ment was conducted at Eldorado do Sul, RS, Brazil, during the 1988/89 growing season. Four plant densities (30,000; 45,000; 60,000 and 75,00 0 pl/ha) and two planting dates (July, 27(th) and September, 19(th)) w ere tested with and without fertilizer application. The seed moisture at 29 and 36 days (first planting date) and at 22 and 29 days (second planting date) after the anthesis was higher in lower density. Plant h eight, at the stages R(1) and R(6), increased as plant density increas ed. Stem and head diameters decreased as plant density increased. In a ll treatments, plant lodging or plant breaking broken was not signific ant, regardless of sowing date.