Influence of air temperature on composition of sunflower achene

Abstract

Regression analysis was made between daily maximum, minimum and mean air temperature during flowering and physiological maturity period and oil content on achene of three sunflower cultivars: IAC-Anhandy; VNIIMK; and Contisol-621, cultivated in Monte Alegre do Sul, SP, Brazil, with the objective of stablishing the influence of air temperature on achene composition of the three cultivars. Oil content showed quadratic relation with minimum air temperature for IAC-Anhandy and VNIIMK while for Contisol-621 the quadratic relation was with maximum air temperature. These relations showed the respective optimum points of temperature: 10^oC; 12.5^oC; and 24^oC. The same analysis carried out only for VNIIMK cultivar with relation to protein content and fatty acid composition showed that protein content was influenced by maximum air temperature, with optimum point in 25^oC. For the fatty acid composition it was observed that palmitic, oleic and linoleic acids showed best correlation with minimum air temperature, palmitoleic acid with maximum air temperature, and stearic acid with mean air temperature. Air temperature did not show any influence on myristic and behenic acids levels.