Sclerotium rolfsii na emergência e crescimento inicial do girassol em diferentes solos e temperaturas

Abstract

The sunflower (Helianthus annuus L.) is a cropthathasmany purposesinour society andits cultureshouldhave somecareand handling, particularly with respect to soil pathogens. The soil pathogenic fungi, such as Sclerotiumrolfsii, are responsible for significant losses in crop sunflower. Thus, the objective of this study was to evaluate the action of S. rolfsii on emergence and early growth of sunflower in different soils and temperatures. For the first experiment, sunflower seeds were sown in soil: typic São Luiz Gonzaga-RS and RS-PlintosoloItaqui., Were infested seedlings with S. rolfsii. In the second experiment sunflower seeds were sown in latosol infested with the pathogen, the temperatures of 15, 20, 25 and 30 º C. Evaluations were made concerning the emergence and early growth of the crop. At first we obtained clearly higher incidence of the pathogen in the Oxisol. In the second experiment resulted in no significant being that there was a higher infestation at 25 º C and 30 º C. However we conclude that the latossolo by having the higher clay content, he focused more moisture and consequently the fungus had a greatest proliferation, and showed that the temperature did not interfere in any way.