Adaptações metodológicas de testes em sementes de arroz: novas alternativas para o controle interno

Abstract

Rice (Oryza sativa L.) is one of the crops of great economic and social importance for Brazil so its cultivation demands high quality seeds. Production conditions have required seed producers to use modern technologies. Interest in vigor tests is highlighted, due to the possibility of identifying possible differences in quality, thus complementing the germination test. The objective of this research was to adapt the methodologies of cold test, accelerated aging, electrical conductivityand K leaching in rice seed lots. The present study was installed and conducted at the Laboratório Didático de Análise de Sementes Flávio Farias Rocha. Rice seeds from cultivar IRGA 424 RI, represented by 21 seed lots were used. The research was carried out in two stages: first the characterization of the lots; followed by methodological adaptations of cold test, accelerated aging, field emergency and K leaching. In conclusion, with temperatures of 2ºC to 5ºC for two days, the cold test was efficient for stratification of rice seed lots compared to field emergence. For the accelerated aging test, the methodologies C (pre-treatment in refrigerator at 5- 10ºC for 24 hours then BOD at 42 ° C for 48 hours) and J (pre-treatment in oven 35-40ºC for 2 hours after BOD at 45ºC for 48 hours). ) are efficient for stratification of rice seed lots compared to field emergence. For the field emergency test, the 12-hour rice seed immersion period was the most appropriate adapted methodology. There is no correlation of the adaptations tested with the emergency in the field. The methodologies J (25 seeds at 30 ° C) and P, R, and S (50 seeds at 25 ° C) were efficient to stratify the lots. There was a correlation with the emergency field test of J (25 seeds at 30 ° C) and P (50 seeds at 25 ° C) methodologies showing that the potassium leaching test is efficient to evaluate the vigor of rice seeds.