Incremento germinativo da semente do café (Coffea arabica L.): aplicação de um campo magnético uniforme com monitoramento pelo biospeckle laser

Abstract

One of the main obstacles in producing coffee (Coffea arabica L.) seedlings is the fact that coffee seeds present low germination rates as well as irregular germination, which directly affect seedling quality and planting time in the field. Research on coffee (Coffea arabica L.) seed pre-germination treatments has been conducted to decrease germination time and improve seedling uniformity in order to increase efficiency in the field. The objective of the present study was to evaluate the effect of stationary magnetic field pre-germinative conditioning on coffee seed germination. Three thousand seeds were placed in germinators, where they were subjected to magnetic fields at constant intensities of 10 mT and 28 mT for a time interval of 6 days during germination. The embryonic region of the seeds was illuminated by a laser and images were captured by a Biospeckle Laser (BSL). After processing the images, activity levels in the embryonic region were compared with the data obtained through traditional seed physiological analysis, including Emergence Speed Index, isozymes (SOD, CAT, EST, MDH, and endo-β-mannanase), membrane integrity, germination, Speed Germination Index (SGI), and protrusion. The magnetic field pretreatments of both intensities over the six-day period improved both cell membrane permeability and were associated with early activation of the antiradicle system, in addition to promoting faster and more uniform seed germination.