Determination of appropriate level of aluminum activity in hydroponics for the screening of tropically adapted soybean varieties

1 SUMMARY A hydroponics experiment was conducted at the Crop Science Laboratory of the University of Agriculture, Makurdi, Nigeria, in 2002 with the objective of determining the appropriate levels of aluminium for the screening of tropically adapted genotypes of soybean. Fifteen soybean genotypes constituted the main plots while ten levels of aluminium activity constituted the subplots in a split-plot design. The experiment was replicated three times. The soybean seedlings were germinated for 4 days and transferred to nutrient solutions containing the various levels of aluminium. The seedlings grew for 3 days (3D) in the hydroponics, bringing their total age to 7 days. Data were taken for primary root length, shoot length, root dry weight and shoot dry weight of plants grown at 8 levels of aluminium activity(0, 5, 50, 100, 150, 200, 250 and 300;MAl 3+ ). No data was taken for the 350 and 400;MAl 3+ levels of aluminium activity due to death of seedlings grown at these two levels. Highly significant Al, genotype, and first order interaction effects were observed. Four levels of Al activity (0, 5, 50 and 300;MAl 3+ ) were selected and recommended as appropriate for the screening of tropically adapted genotypes of soybean.