Qualidade sanitária e fisiológica de sementes de pinhão manso tratadas com fungicidas

ABSTRACT

Two experiments were conducted at the Federal University of Grande Dourados, in order to evaluate the efficiency of fungicides, Carboxin + Thiram and Carbendazin + Thiram at different doses on seed health and its effect on seedling vigor. The fungicides, Carboxin + Thiram was evaluated at doses of 350, 450 and 550 mL and Carbendazin + Thiram at doses of 200, 300 and 400 mL, the respective doses for 100 kg of seeds. The experimental design for both trials was completely randomized design with 7 treatments, 10 repetitions for the test of sanity and 5 for analysis of the vigor. We analyzed the percentage incidence of fungi in seed and seedling vigor, through a field emergence, index of emergence speed and plant height. We report the incidence of Aspergillus sp., Penicillium sp., Fusarium sp. Phomopsis sp. and Rhizopus sp., and Carboxin + Thiram at a dose of 550 ml, the treatment most effective in controlling pathogens. For field emergence, both fungicides were effective, providing increases ranging from 48.9 to 97.4% of emergency. The index of emergence speed was favored by treatments with Carboxin + Thiram at a dose of 550 mL and Carbendazin + Thiram at doses of 300 and 400 ml. It was found that Fusarium sp. was the pathogen with the highest percentage of incidence on seeds, however, the highest correlation with the low emergence were observed by the presence of Penicillium sp. and Phomopsis sp.

RESUMO

Foram desenvolvidos dois experimentos na Universidade Federal da Grande Dourados, com o objetivo de avaliar a eficiência dos fungicidas, Carboxin + Thiram e Carbendazin + Thiram, em diferentes doses, na sanidade de sementes e seu efeito sobre o vigor de plântulas. Os fungicidas, Carboxin + Thiram foi avaliado nas doses de 350, 450 e 550 mL e Carbendazin + Thiram nas doses de 200, 300 e 400 mL, sendo as respectivas doses para 100 kg de sementes. O delineamento experimental para ambos os ensaios foi inteiramente casualizado com 7 tratamentos, 10 repetições para o ensaio de sanidade e 5 repetições para análise do vigor. Analisaram-se a porcentagem de incidência de fungos nas sementes e o vigor de plântulas, por meio da emergência a campo, índice de velocidade de emergência e altura de plantas. Relata-se a incidência de Aspergillus sp., Penicillium sp., Fusarium sp., Phomopsis sp. e Rhizopus sp., sendo Carboxin + Thiram na dose de 550 mL, o tratamento mais eficiente no controle dos patógenos. Quanto à emergência a campo, ambos os fungicidas foram eficientes, proporcionando aumentos que variaram de 48,9 a 97,4% de emergência. O índice de velocidade de emergência foi favorecido pelos tratamentos com Carboxin + Thiram na dose de 550 mL e Carbendazin + Thiram nas doses de 300 e 400 ml. Constatou-se que Fusarium sp. foi o patógeno com maior percentual de incidência sobre as sementes, todavia, as maiores correlações com a baixa emergência foram observadas pela presença dos fungos Penicillium sp. e Phomopsis sp.