Phytochemical profile and antifungal action of Anadenanthera colubrina extract on the quality of maize seeds

Maize (Zea mays L.) is among the most cultivated crops in the world and can be affected by several diseases, especially those transmitted by seeds. The study of alternatives to fungicides used for seed treatment has a promising field in essential oils. Thus, this study determined the phytochemical profile of the ethanolic extract from Anadenanthera colubrina (Vell.) Brenan and to evaluate its antifungal activity on the sanitary and physiological quality of maize seeds. The seeds used were of the Jaboatão cultivar, which were submitted to the following treatments: control (untreated seeds), commercial fungicide (dicarboximide) and A. colubrina extract at 200, 400, 600, 800, and 1,000 ppm. The seeds were subjected to sanitary and germination tests in a completely randomized experimental design. Phytochemical prospecting of A. colubrina extract indicated the presence of alkaloids, tannins, flavonoids and saponins, as well as the major compounds lupeol, gallic acid, ferulic acid, catechin and quercetin. The A. colubrina extract reduced the incidence of Aspergillus spp., including Aspergillus niger, Alternaria spp., Curvularia spp. and Fusarium spp. at all concentrations. The highest concentrations (800 and 1,000 ppm) of the A. colubrina extract reduced the incidence of Penicillium spp. and yielded an effective control of Rhizoctonia spp. The extract of A. colubrina did not present phytotoxic effect, guaranteeing the viability and vigor of maize seeds.

Sanitary and physiological quality of 'purple' corn (Zea mays L. ) seeds submitted to thermotherapy / Qualidade sanitária e fisiológica de sementes de milho 'Roxo' (Zea mays L. ) submetidas à termoterapia

The use of seeds with good sanitary and physiological potential ensures the establishment of the crop, with a uniform, vigorous and disease-free seedling stand, which will result in good productivity levels. Seen that, the objective was to evaluate the sanitary and physiological quality of purple corn seeds (Zea mays L.) submitted to thermotherapy. They were subjected to heat treatment with immersion in sterile distilled water (SDW) heated at 50, 60 and 70 °C for 1, 2, and 3 minutes. The control (0 min) correspondens only to immersing the seeds in SDW, which were submitted to sanitary and germination tests in a completely randomized experimental design, in a factorial arrangement 3 × 3 + 1 (exposure time × temperature + additional control). Data were subjected to analysis of variance, and the means were compared with the Scott-Knott test up to 5% of probability, with the aid of the statistical program SISVAR®. Immersing Zea mays seeds in hot water at 50, 60 and 70 °C for 1, 2, and 3 minutes is efficient to prevent the increased incidence of Aspergillus sp., Penicillium sp., and Fusarium sp. The heat treatment at 60 °C for 1 and 2 minutes of immersion reduces the incidence of fungal mycoflora without impairing the physiological quality of seeds.(AU)

O uso de sementes com bom potencial sanitário e fisiológico garante o estabelecimento da cultura, com estande de plântulas uniformes, vigorosas e livres de doenças, que consequentemente resultará em bons níveis de produtividade. Diante do exposto, objetivou-se avaliar a qualidade sanitária e fisiológica de sementes de milho roxo (Zea mays L.) submetidas à termoterapia, por meio de tratamento térmico com imersão em água destilada esterilizada (ADE), aquecida à temperatura de 50, 60 e 70 °C por 1, 2 e 3 minutos. O controle (0 min) correspondeu apenas à imersão das sementes em ADE. As sementes foram submetidas aos testes de sanidade e germinação em delineamento experimental inteiramente randomizado em esquema fatorial 3 × 3 + 1 (tempo de exposição × temperatura + controle adicional). Os dados foram submetidos à análise de variância e as médias foram comparadas pelo teste de Scott-Knott até 5% de probabilidade, com o auxílio do programa estatístico SISVAR®. A imersão das sementes de Zea mays em água quente a 50, 60 e 70 °C durante 1, 2 e 3 minutos é eficiente para impedir o aumento da incidência de Aspergillus sp., Penicillium sp. e Fusarium sp. O tratamento térmico a 60 °C por 1 e 2 minutos de imersão reduz a incidência da micoflora fúngica, sem prejudicar a qualidade fisiológica das sementes.(AU)