Aluminum-sensitive ‘Monon’ wheat (Triticum aestivum, spp vulgare (Vill. Host) Mac Key and ‘Kearney barley (Hordeum vulgare) (L. emend. Lam) varieties had higher root cation exchange capacities and induced lower pH levels in nutrient solutions than did Al-tolerant ‘Atlas 66’ wheat and ‘Dayton’ barley varieties. Sensitive varieties contained higher concentrations of Al (and usually P) in their roots and lower concentrations of Ca in their tops than tolerant varieties, when grown in solutions containing Al. Furthermore, roots of Al-sensitive varieties made less growth and contained higher concentrations of Al than those of tolerant varieties, even when the two were grown in the same container of vigorously aerated nutrient solution. This suggests either that zones of differential pH still exist around the roots of different varieties or that sensitive varieties absorb more Al at the same pH or both. Whether the lower Al tolerance of certain varieties is simply the result of greater accumulation of Al by roots, greater sensitivity to the same concentration of Al already absorbed, or both, cannot be determined from the present study. Differential Al tolerance of varieties was not closely related to differences in the Al or P contents of plant tops.

This paper deals with a survey on chemical compositions of 39 forage sugar cane varieties carried out at the Bromatology Laboratory of the E.S.A. "Luiz de Queiroz" (5th chair). Samples were taken at Sugar Cane Experimental Station "Jose Viziolli", Piracicaba, SP, and the material was analised by standard methods. The main conclusions can be summarised as follows: 1. All varieties showed low protein and mineral contents, but were high in crude fiber and nitrogen free extract fractions. 2. A small, but positive correlation was observed between crude fiber and protein content. 3. The amount of observed variation concerning the various nutrient fractions could be used to select better forage sugar cane varieties.

Plântulas de trigo da variedade Piratiní suscetível ao "crestamento" e da variedade Colônias, considerada resistente, foram cultivadas em solução nutritiva empregando-se a técnica das raízes divididas. Estas variedades foram submetidas aos tratamentos correspondentes as concentrações de 0,2 a 6,0 ppm de alumínio, sendo aplicados 25 microcuries de fósforo radioativo que foram retirados posteriormente a fim de que fôsse determinada a sua translocação. Em ambas variedades observou-se que a concentração de alumínio nas fôlhas não influia na translocação do fósforo (32P) para as fôlhas novas. Entretanto, as relações entre os teores de alumínio nas fôlhas e os teores de fósforo nas fôlhas, hastes e raízes foram diferentes nas variedades estudadas. | Wheat seedlings (Triticum vulgare L.)var. Piratiní susceptible to aluminum toxicity (crestamento), and var. Colônias, tolerant to aluminum, were grown in nutrient solution with divided root system. One part of the roots were grown in nutrient solutions lacking phosphorus and containing from 0,0 at 6,0 ppm of aluminum while the other part of the root system was grown in nutrient solutions containing all nutrients and 25 uCi of 32P as tracer. In both varieties, the aluminum concentration in leaves did not effect the translocation of phosphorus 32P to the new leaves. Both varieties showed a different P/Al relations in leaves, seem and roots.

‘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 2370, respectively, for Herta. Corresponding root yields were 100, 112, 113, 111, 76, and 6670 (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.