Coffee is one of the world’s most traded agricultural products. Modeling studies have predicted that climate change will have a strong impact on the suitability of current cultivation areas, but these studies have not anticipated possible mitigating effects of the elevated atmospheric [CO2] because no information exists for the coffee plant. Potted plants from two genotypes of Coffea arabica and one of C. canephora were grown under controlled conditions of irradiance (800 μmol m-2 s-1), RH (75%) and 380 or 700 μL CO2 L-1 for 1 year, without water, nutrient or root development restrictions. In all genotypes, the high [CO2] treatment promoted opposite trends for stomatal density and size, which decreased and increased, respectively. Regardless of the genotype or the growth [CO2], the net rate of CO2 assimilation increased (34-49%) when measured at 700 than at 380 μL CO2 L-1. This result, together with the almost unchanged stomatal conductance, led to an instantaneous water use efficiency increase. The results also showed a reinforcement of photosynthetic (and respiratory) components, namely thylakoid electron transport and the activities of RuBisCo, ribulose 5-phosphate kinase, malate dehydrogenase and pyruvate kinase, what may have contributed to the enhancements in the maximum rates of electron transport, carboxylation and photosynthetic capacity under elevated [CO2], although these responses were genotype dependent. The photosystem II efficiency, energy driven to photochemical events, non-structural carbohydrates, photosynthetic pigment and membrane permeability did not respond to [CO2] supply. Some alterations in total fatty acid content and the unsaturation level of the chloroplast membranes were noted but, apparently, did not affect photosynthetic functioning. Despite some differences among the genotypes, no clear species-dependent responses to elevated [CO2] were observed. Overall, as no apparent sign of photosynthetic down-regulation was found, our data suggest that Coffea spp. plants may successfully cope with high [CO2] under the present experimental conditions.

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Studies on nutritional efficiency of phosphorus in conilon coffee plants are important tools to unravel the high limitation that natural low levels of this nutrient in soil impose to these species cultivars. Therefore, this study aimed at evaluating the nutritional efficiency and the response to phosphorus of conilon coffee clones. Plants were managed during 150 days in pots containing 10 dm³ of soil, in greenhouse. A factorial scheme 13 x 2 was used, with three replications, being the factors: 13 clones constituting the clonal cultivar "Vitória Incaper 8142" and two levels of phosphate fertilization (0% and 150% of the P2O5 usualy recommended), in a completely randomized design (CRD). The results indicate a differentiated response of dry matter production and of phosphorus content on each level of phosphate fertilization for the conilon coffee clones and that CV-04, CV-05 and CV-08 clones are nutritionally efficient and responsive to the phosphate fertilization.

The objective of this study was to evaluate the nutritional efficiency of phosphorus in clones of conilon coffee, in greenhouse condition. A factorial design 13 x 4 was used, with three replications, and the factors being: 13 clones that compose the clonal cultivar "Vitória Incaper 8142" and four levels of phosphorus fertilization (0%, 50%, 100% and 150% of the recommended P 2 O 5 for the culture) in a completely randomized design (CRD). The cultivation consisted of a period of 150 days, then in each experimental unit, the values of dry matter and phosphorus content of the vegetative parts were obtained. The indices of nutritional efficiency (absorption, translocation and utilization) were calculated. The clones of conilon coffee showed different behavior for all variables at each level of fertilization with P 2 O 5 . The mass of dry weight, phosphorus content, and efficiency of phosphorus utilization of the clones increase linearly with the increase of P 2 O 5 . The efficiency of phosphorus absorption, depending on the levels of P 2 O 5 applied to the clones of conilon coffee, has set to a quadratic model. The translocation efficiency of phosphorus, depending on the levels of P 2 O 5 applied, is different for clones of conilon coffee, with a linear characteristic and also quadratic.

The objective of this study was to evaluate the nutritional efficiency of phosphorus in physic nut (Jatropha curcas L.) genotypes, under controlled conditions. The experiment was arranged in a randomized block design, in a factorial scheme 10 x 2, using ten physic nut genotypes, two levels of phosphorus available in the soil (10 and 60 mg dm^-3), and four replications. Cultivation consisted of a period of 100 days, with vegetative growth being evaluated in each experimental plot, with the dry matter mass values, phosphorus contents in the vegetative parts, nutritional efficiency indices, and alpha parameter also being obtained. The results show that the physic nut genotypes present greater vegetative growth, dry matter mass accumulation, P content, absorption efficiency and translocation at the high level of phosphorus available in the soil. Genotype CNPAE-C2 is the most efficient and responsive to phosphoric fertilization

This study investigated the severity of leaf rust and brown eyespot in genotypes of Coffea arabica L. cultivated with high plant density in the region of Caparaó-ES. The experiment was conducted in a competition field, cultivated with high plant density (8333 plants per hectare), following a randomized block design, with 16 genotypes and four replications. The plants were evaluated during consecutive harvests to study two complete reproductive cycles (from 2010 to 2012). Data were obtained for the phenologicalstages of flowering, graining, maturation and vegetative rest of each cycle. The severity of leaf rust (Hemileia vastratrix) and brown eyespot (Cercospora coffeicola) was evaluated using descriptive scales. It was observed that the genotypes are able to keep a considerable level of resistance to the leaf rust and brown eyespot when cultivated with increased density. The genotypes presented variability regarding the severity of the leaf rust and brown eyespot, indicating the existence of differential levels of resistance between them. For cultivation with high plant density, the genotypes Katipó, Paraíso MG H419-1, H419-3-3-7-16-4-1-1

Reduced soil fertility has been surpassed by the supply of mineral nutrients, which results in increased rates of plant production and costs. In this context, the optimization of plants' nutritional efficiency is critical to increase productivity and reduce the cost of agricultural production systems. The nutritional efficiency of plants is conditioned by numerous factors and the growing environment. Therefore, the knowledge of genetic basis and mode of inheritance can assist in selecting genotypes with desirable agronomic characteristics coupled with nutritional efficiency and genetic variability. The trend of expanding agricultural frontiers has increased interest in the use of genotypes with the potential to adapt to adverse conditions of soil fertility. Within crops, the coffee beans are the second most traded commodity in the world. In this sense, optimization of nutritional efficiency of the coffee has a positive impact on the sum of efforts to make sustainable activity. This review aimed to present a systematic analysis of the nutritional efficiency of the coffee.

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