The effect of zinc deficiency on plant growth and levels of carbonic anhydrase, ribulose diphosphate carboxylase, glycolic oxidase, and malic dehydrogenase was measured in two varieties of Phaseolus vulgaris L. Varieties ‘Saginaw’ and ‘Sanilac’ were grown in nutrient solution in a growth chamber at 0.005, 0.05, and 0.2 ppm zinc. Both varieties showed a similar increase in dry weight production after 4 1/2 weeks of growth with increasing zinc concentrations. Enzyme, chlorophyll, and zinc analyses were made on the first, third, and fifth trifoliate leaf from the bottom of the plants. The level of carbonic anhydrase per unit leaf area was dramatically decreased in either variety at 0.005 and 0.05 ppm zinc when compared to 0.2 ppm zinc. The most severe reduction of carbonic anhydrase and zinc in the leaves was in the third and fifth trifoliate leaf. A decrease in growth with the lower levels of zinc was paralleled by a decrease in carbonic anhydrase activity and zinc levels in the younger trifoliate leaves. Zinc deficiency in the two varieties had little effect on the levels of ribulose 1,5.diphosphate carboxylase, glycolic oxidase, or mallc dehydrogenase.

Two varieties of corn (Zea mays L.) showed differences in efficiency of Fe utilization when grown in hydroponic solutions and under field conditions. Under hydroponic conditions, ‘Seneca XX155’ showed greater susceptibility to P-induced Fe stress than ‘Wisconsin 335A’, although its foliage contained more Fe. This susceptibility was related to reduced Fe translocation caused by relatively high P concentrations. Levels of P > 22 ppm in the nutrient solution produced significant reduction in foliage Fe of both varieties. Field studies showed significant reduction of tissue Fe at a fertilization level of 50 kg/ha compared to controls. Unlike results from hydroponic studies, no change in Fe status occurred at progressively higher rates of applied P (50–400 kg/ha) under field conditions. Levels of tissue Fe were never < 160 ppm following soil P applications.

In this paper the nutrient absorption by wheat plants is presented. Two varieties of wheat, BH 1146 and IAS 3795, were grown in Mitscherlich pots under greenhouse conditions and supplied with all nutrients, including micronutrients. Plant samples, obtained at 10-day intervals, were analysed for N, P, K, Ca, Mg and S. The amounts of nutrients absorbed were diferent between the two varieties. Furthermore, the BH variety absorbed more nitrogen than other nutrients, while for the IAS variety potassium was the element absorbed in larger amounts. Absorption of P, S, Ca, Mg was small for both varieties. | Estudou-se a absorção dos nutrientes essenciais das variedades de trigo (Triticum aestivum L.) BH 1146 e IAS 3795, cultivadas em vasos de Mitscherlich em casa de vegetação, empregaudo-se Latossolo Vermelho-Escuro fase arenosa, proveniente do município de Capão Bonito. Durante todo o ciclo vegetativo da cultura, a cada 10 dias, colheram-se plantas, para serem analisados os elementos N, P, K, Ca, Mg e S. Verificou-se sensível diferença na entração dos nutrientes, entre ambas as variedades. Assim, enquanto na BH o nitrogênio e, a seguir, o potássio foram os nutrientes absorvidos em maiores quantidades, seguindo-se, em quantidades menores, o fósforo, o cálcio, o ennofre e o magnésio, na variedade IAS o potássio foi absorvido em muito maior quantidade que o nitrogênio, e depois dele, na ordem, o cálcio, o fósforo, o ennofre e o magnésio.

Estacas de amoreira (Morus alba L.) das variedades Formosa, Calabreza e Fernão Dias foram cultivadas em silica e irrigadas com solução nutritiva completa e submetida a tratamentos omitindo-se um macronutrientes por vez. Num tratamento suplementar omitiu-se o boro. As plantas exibiram sintomas de carência, que foram descritos, na seguinte ordem de aparecimento: nitrogênio, magnésio, cálcio, fósforo, potássio e boro. Não foi obtida a sintomatologia da carência de enxofre. As deficiências foram confirmadas através da análise química das folhas e dos ramos de plantas sadias e deficientes. | Slipes of the varieties Fernão Dias, Formosa and Calabreza were grew in pots containing pure quartz sand. Several times a day all the plants were irrigated with Hoagland and Arnon's solution of 30 days. After, that period, groups of plants (5) were irrigated with nutrient solution lacking one nutrient (-N,-P,-K,-Ca,-Mg,-S and -B). Soon as the deficiences symptoms become visible the plants were harvested and analysed for the macronutrients and boron. The plants showed deficiencies symptoms in the following order: nitrogen, magnesium, calcium, phosphorus, potassium and boron. No sulphur deficiencies symptoms were observed. The tissue analysis of the leaves of plants showing deficiencies symptoms or not were:

Acid soil and solution culture studies showed that ‘Atlas 66’ wheat (Triticum aestivum L.) from North Carolina was more tolerant to excess Al but less tolerant to excess Mn than ‘Monon’ wheat from Indiana. In greenhouse pots of Al-toxic Bladen soil (pH 4.6 to 5.1) the top yields of Atlas 66 were significantly higher (5% level) than those of Monon; liming the soil to pH 5.8, however, equalized top yields of the two varieties. In Mn-toxic Zanesville soil (pH 4.7 to 5.2) the varietal yield difference was just the reverse. At pH 5.2 the tops of Monon plants had fewer leaf symptoms (rolling and chlorotic spots) and yielded significantly more than those of Atlas 66; at pH 5.9 or 6.9, however, the two varieties were not significantly different in top yield. In nutrient solutions containing between 4 and 32 ppm Mn at pH 4.6 the tops of Monon showed fewer leaf symptoms of Mn toxicity and yielded significantly more than those of Atlas 66, but with O or 2 ppm Mn added, the top yields of the two varieties were not significantly different. With Mn levels of 2 to 32 ppm, Monon root yields were significantly higher than those of Atlas 66, but with no Mn added the two root yields were not significantly different. At all Mn levels of 2 to 32 ppm in solution both tops and roots of Monon contained higher Mn concentrations than those of Atlas 66, but Monon plants showed less injury. For example, in Monon tops 2,561 ppm Mn was associated with a yield reduction of 12%. In Atlas 66 tops 1,250 ppm Mn (the highest concentration reached in Atlas 66) was accompanied by a yield reduction of 21%. In Monon roots 8,534 ppm Mn was associated with a root yield reduction of 20%, but 7,172 ppm Mn in Atlas 66 roots coincided with a 45% reduction in root yield. Tolerance to one acid soil factor in a given plant genotype does not necessarily mean tolerance to another.

This work describes two pot trials conducted under glasshouse conditions on Omahau (pH 5.6), Grampians (pli 5.6) and Wolds (pH 6.2) soil from the McKenzie Country, South Island, New Zealand, to investigate the adaptability of lucerne to acid soil conditions. Lime, phosphorus and molybdenum were applied at two rates (none and some) to two varieties of lucerne of known different origin and characteristics, Narragansset (M. media Per.) and Tierra de Campos (M. sativa L.) grown on the three soils. Phosphorus and molybdenum were applied to subterranean clover (Trifolium subterraneum L.) cv. Mount Barker also grown on the three soils, to compare the responses to fertilisers of this legume, whose adaptability to acid soil conditions is well known, with the responses of lucerne and so determine what are the general nutrient requirements of these legumes and the specific requirements of lucerne. Phosphorus proved to be an essential element for the nodulation and growth of legumes on Omahau and Wolds soils. Subterranean clover shows a better ability than lucerne to get phosphorus from the Grampian soil which has a medium phosphorus level. Molybdenum was necessary on the three soils for getting maximum production of lucerne and subterranean clover. Lime was necessary for maximum production of lucerne on Wolds and Omahau soils. Although lucerne Tierra de Campos produced better than Narragansset, nothing can be concluded about their differences in adaptability to acid conditions.