Alfalfa, red clover, ladino clover, alsike clover, and birdsfoot trefoil were germinated in soil (pH 6.5) or in inert silica (8 mesh) and allowed to root in a [Formula: see text] Hoagland and Snyder's nutrient solution (pH 4.5) with 0, 0.5, 1, 2, 4, and 10 p.p.m. of added aluminum. Each species, germinated in silica, was also rooted in an unlimed acid soil (pH 4.6) and the same soil limed to a pH of 6.5.Concentration of aluminum ion remaining in solution was 0, 0.1, 0.2, 0.5, 1.0, and 2.0 p.p.m. Saturation extracts of the unlimed and limed soil contained 0.45 and 0.0 p.p.m respectively of aluminum ion in solution. The pH of the nutrient solutions with 0.5, 1, and 2 p.p.m. of added aluminum increased to 5.0 or higher in 24 hours while that with 4 and 10 p.p.m. of added aluminum remained relatively constant.Seedling weight and chemical composition of the tops and root portions varied significantly between species. Alfalfa and red clover showed the most vigorous rate of establishment, and yields were higher with 0.1 and 0.2 p.p.m. concentration of aluminum ion than with the zero treatment. Significant restriction of top and root growth of all species occurred with less than 1.0 p.p.m. of aluminum ion while 2.0 p.p.m. was toxic to root growth. Growth restrictions were more severe at 21 days after seeding than at the 28- or 32-day stages. Yield of tops and roots growing into unlimed acid soil were 73 and 71% respectively of those growing into limed soil. Aluminum taken up by the plant was concentrated in the roots and only with the concentration of aluminum at 2.0 p.p.m. was the content in the tops increased significantly. Phosphorus in the roots, which increased significantly with aluminum ion concentration, was apparently immobilized by aluminum. Percent Ca in the roots increased and in the tops decreased with increasing concentrations of aluminum. Content of K and Mg also varied with aluminum concentration.

Alfalfa plants 'were grown in the g-reenh-ouse to three develop.-mer-r^tal stages'

‘Charlottetown 80’ and ‘Herta’ barley were grown in nutrient solution (pH 4.3) with 0, 4, 6, 8, 10, and 12 ppm of added aluminum, in peat at pH values of 4.3, 5.5, and 6.2 each with 0, 3, 6, and 12 ppm of added Al, and in mineral soil at pH values of 4.7, 5.5, and 6.5. Actual concentrations of aluminum ion in solution were 0, 0.7, 1.5, 2.2, 2.6, and 3.0 ppm. Using the yield of Charlottetown 80 at 0 ppm as l00%, the yields of tops for the above Al concentrations were 100, 100, 96, 93, 49, and 42% for Charlottetown 80 and 41, 49, 32, 31, 20, and 23%, respectively, for Herta. Corresponding root yields were 100, 112, 113, 111, 76, and 66% (Charlottetown 80) and 42, 48, 39, 32, 24, and 31% (Herta). Saturation extracts from peat (pH 4.3) contained 2.0 ppm Al which reduced the top and root yields to 56 and 43% and 55 and 43% for Charlottetown 80 and Herta, respectively. Heavy fertilization reduced root yields in unlimed soil and increased root yields in limed soil. Percent K, Ca, and Mg in tops and roots decreased while percent Al increased with increasing Al concentration. Both uptake and translocation of P decreased with increasing Al concentration.

No abstract

This contribution on Kalmia angustifolia L., sheep-laurel (Ericaceae), is part of a series that presents biological information on plants that are weedy in Canada. Kalmia angustifolia is a weed of lowbush blueberry fields and pastures in eastern Canada. It occurs in Newfoundland, Prince Edward Island, Nova Scotia, New Brunswick, Quebec, and Ontario.