The Effects of Aqueous Seaweed Sprays on the Growth of Maize

Abstract

AbstractSeaweed extract (Goemar GA 14), applied as a foliar spray increased the total fresh matter production ofmaize seedlings by 15 to 25% over the control. This was reflected in the increase of root and stem mass perplant. However, only minor differences were measured in stomatal resistance just after treatment and in netcarbon assimilation rate two weeks after spraying. No other significant differences were observed in gazexchanges characteristics. The physiological mechanisms responsible for the beneficial effects of seaweedconcentrates on plants and the nature and mode of action of the compounds contained in these concentrateshave not yet been elucidated. Introduction Seaweed extracts have been marketed for several yearsas fertilizers. The main seaweed extracts known toplay a useful role in agriculture are: Maxicrop (Sea-born), Algifert (Marinure), Goemar GA 14, Kelpak66, Seaspray, Seasol, S.M.3, Cytex and Seacrop 16.The diversity of commercial seaweed products hasarisen not only from the use of different seaweedspecies, but also from the method of preparation,which varies according to the manufacturer.Many different beneficial effects have been recordedfor crops treated with seaweed extracts. As well asincreased crop yields and improved quality of theproducts after harvest, seaweed extracts have beenshown to ensure better seed germination, increasenutrient uptake, improve resistance of plants to un-favourable conditions of environment (frost, drought)and reduce incidence of fungal, insect and nematodeattack (Jolivet