Carlos Pimentel | Universidade Federal Rural do Rio de Janeiro (original) (raw)

Papers by Carlos Pimentel

Water scarcity, which already occurs for more than a billion people worldwide, will worsen furthe... more Water scarcity, which already occurs for more than a billion people worldwide, will worsen further, and the water supply available for future generations, especially for use in agriculture, will be increasingly restricted. Above all, in arid and semi-arid regions, irrigated agriculture uses more than 70 to 80% of the total water available and is essential to increase food production in these regions, where the population is rapidly increasing [1]. The world's population in 2004 was more than 6,000,000, of which around 5,000,000 were in developing countries, and 20% of this population has remained undernourished since the 1990s [2]. For this time, water management in agriculture, in the current era of scarcity, should be engaged to implement water use efficiency (WUE), spending fewer resources and producing less expensive plant protein [3,4]. In the past, during the postwar "green revolution", the paradigm of agriculture was to modify the environment (heavy fertilization, irrigation, and mechanization, with energy expenditure) to adapt it to the plant, with the generation of so-called high-yield varieties (HYVs), with high harvest index (HI: Dry Weight [DW] of the organ harvested. plant DW-1), for mechanized harvesting and responsive to the application of fertilizers, which were cheap at the time [1], but less adapted to the stresses, which was mitigated by energy expenditure, in irrigation and mechanization, and fertilizers applied [5]. For example, in grasses, the induction of progressive tillering, as occurs in the millet and sorghum, is one of the mechanisms of escape from environmental stresses because each inflorescence will have a different period of fertilization increasing the chances of producing some viable panicles [5]. However, this characteristic would prevent mechanized harvesting, but small farmers in marginal areas of agriculture do not use mechanic harvesting. Marginal agriculture areas are frequently subjected to environmental stresses and have soils with poor nutrient content [3]. In the past, during the green revolution, it was always a characteristic undesirable for plant breeding programs to improve yield. In addition, the increase in HI was often obtained with a reduction of volume and root area, which is very important to implement the WUE [6]. Therefore, the genetic basis for the environmental adaptation of the most improved crop by man, such as maize, has been dramatically diminished. After the oil and energy crisis in the 1970s, the paradigm of agriculture has become to modify the plant to adapt it to the environment, with WUE, generating varieties with Low Technological Cost (LCVs) for agricultural production (Figure 1). This adaptation to environmental stresses can also be found in local landraces used by the small farmers living in marginal areas for agriculture, which needs to be better studied and recommended to increase food safety in these areas [3].

Seropédica: Edur, 2004

... Coordenação geral: Alberto MT Magalhães Revisão de texto: Angela Portocarrero Projeto gráfico... more ... Coordenação geral: Alberto MT Magalhães Revisão de texto: Angela Portocarrero Projeto gráfico: Luciana Costa Leite Ilustrações e gráficos: Carlos ... Cezar de Almeida Pimentel e Aniela Maria Niedenthal Pimentel, pela minha educação; a minha esposa, Sandra Greenman, e ...

Cowpea is a low-cost protein source for human nutrition for the world's impoverished regions. The... more Cowpea is a low-cost protein source for human nutrition for the world's impoverished regions. Therefore, the yield and total grain protein content (TGPC) of two modern commercials genotypes, Novaera and Gurguéia, and two traditional local genotypes, Paulistinha and EPACE-10, were studied. Also, leaf area and dry weight, leaf soluble protein content, and chlorophyll a fluorescence, parameters related to photosynthetic capacity, were used to evaluate genotypes. Under optimal conditions, the yield of EPACE-10 and Paulistinha, with higher TGPC, was lower than for Gurguéia and Novaera, which showed lower TGPC. The four cowpea genotypes showed high lysine content and low methionine and cysteine. The results revealed a negative correlation between yield and TGPC. The modern commercial genotype Novaera showed a high yield with low TGPC but a higher globulin and albumin content than Gurguéia. Thus, it can be used in high-input agriculture. In contrast, the traditional local genotype EPACE-10, with high TGPC and higher amino acid content than Paulistinha, is indicated for low-input agriculture in marginal areas for food safety under climate changes.

: In Brazil, there is a high demand for pearl millet cultivars for grain and biomass production, ... more : In Brazil, there is a high demand for pearl millet cultivars for grain and biomass production, because the reduced number of cultivars offered in the marked. Therefore, the aim of this study was to evaluate the genetic variability for the grain and biomass production traits, as well as others agronomic traits, on a population of pearl millet submitted to a family selection, at the dry season. For this, families obtained form a bulk created by a natural crossing of the african genotypes HKP, Guerguera and Souna III were used for selection. It was phenotypically selected the 10% of the best plants based on producing tillers, panicle length and biomass production, resulting in 121 families, which were then sown on march 2004, at the Experimental Field of Crop Science Department – UFRRJ, in a triplet lattice 11 X 11. Among the traits evaluated, those with higher chances for selection were panicle dry matter, with a heritability at the mean level (h 2 m ) of 0,379 and genetic progress for the family selection, in a mean percentage ( PG SEF %) of 10,47; stover dry matter (with a h 2 m = 0,324 and a PG SEF % = 11,35); total biomass dry matter (with a h 2 m = 0,329 and a PG SEF % = 9,43); panicle mean length (with a h 2 m = 0,569 and a PG SEF % = 8,00); and grain production (with a h 2 m = 0,380 and a PG SEF % = 10,46).

Anais da Academia Brasileira de Ciências, 2020

Journal of Plant Nutrition, 2018

ABSTRACT Sowing nitrogen (N) fertilization can limit biological nitrogen fixation (BNF) reducing ... more ABSTRACT Sowing nitrogen (N) fertilization can limit biological nitrogen fixation (BNF) reducing common bean yield. The aim of this study was to evaluate the effect of sowing N fertilization plus inoculation on the growth and yield of plants in the two seasons of cultivation in Brazil. In the dry season, N fertilization and inoculation promoted a greater shoot dry weight and higher pod number and yield than only inoculated. In contrast, in the rainy season, this treatment promoted no increase in shoot dry weight and yield compared with the inoculated alone. The number of nodules was greater for the inoculated alone treatment, but nodule weight was not affected by N fertilization in either season. Therefore, sowing N fertilization and inoculation can be an agronomic practice to achieve a higher common bean yield in the dry season, while in the rainy season, the inoculation without N fertilization can support a high yield at a lower cost.

Biologia plantarum, 2019

The chlorophyll a fluorescence parameters of four Phaseolus vulgaris L. genotypes were evaluated ... more The chlorophyll a fluorescence parameters of four Phaseolus vulgaris L. genotypes were evaluated under drought in two greenhouse experiments. Under severe water stress, the thermotolerant genotype 'Diplomata' maintained significantly higher values of predawn leaf water potential (Ψw), maximum Fv/Fm and effective (ΦPSII) quantum yield of photosystem II , and non-photochemical quenching than 'Ouro Negro', in the first experiment, and 'A 285' and 'A 222', in the second one. Among these parameters, Fv/Fm showed more differences that discriminated between the genotype responses even when measured at night. Next, a difference between Fv/Fm after sundown and Fv/Fm at dawn on the same day (day ∆Fv/Fm), i.e., the intensity of photoinhibition, and a difference between Fv/Fm at dawn and Fv/Fm after sundown on the day before (night ∆Fv/Fm), i.e. the photoinhibition recovery, were evaluated. Day ∆Fv/Fm and night ∆Fv/Fm were significantly higher for 'Diplomata' under severe water stress in both experiments. In addition, 'Ouro Negro' in the first experiment and all the genotypes in the second showed negative values of night ∆Fv/Fm on the last day of drought when their Ψw were also minimal indicating no recovery from photoinhibition and the need for rehydration. At maturation, stressed plants of 'Diplomata' showed a significantly higher yield than 'Ouro Negro' in the first experiment and the same as 'A 285' in the second. Therefore, the thermotolerant genotype 'Diplomata' also showed drought tolerance, and the use of day ∆Fv/Fm and night ∆Fv/Fm fluorescence analysis was able to discriminate between the tolerances of these genotypes and to indicate the need for rehydration.

African Journal of Agricultural Research, 2017

Experimental Agriculture, 2016

SUMMARYTwo field experiments were conducted during the rainy seasons of 2013 and 2014 to evaluate... more SUMMARYTwo field experiments were conducted during the rainy seasons of 2013 and 2014 to evaluate the effects of biological nitrogen fixation (BNF) and/or sowing N fertilization on the growth and yield ofPhaseolus vulgarisL. In addition, leaf soluble protein content (LSPC) was measured at four growth stages in both seasons. Plants were subjected to the following treatments: only fertilized with 20 kg N ha−1at sowing and with 40 kg N ha−1at 25 days after emergence (DAE) (F); only inoculated withRhizobium tropicistrain SEMIA 4080 at sowing and fertilized with 40 kg N ha−1at 25 DAE (I+N); and inoculated and fertilized with 20 kg N ha−1at sowing and with 40 kg N ha−1at 25 DAE (IF). An additional treatment was done only in the second season and plants were inoculated with no N fertilization at any phase (I−N). Crop growth rate and leaf area index were enhanced by IF and F treatments as compared to I+N treatment, however, net assimilation rate did not differ among the treatments. At the p...

Revista Caatinga, 2017

The objective of this work was to evaluate the growth and yield of cowpea grains in different int... more The objective of this work was to evaluate the growth and yield of cowpea grains in different intercropping systems with millet, in wet and dry seasons. The experiments were performed in the experimental field of the Department of Plant Science of the Federal Rural University of Rio de Janeiro, Brazil, using a randomized block design with three replications and five treatments: T1- sole crop of millet; T2- sole crop of cowpea; T3- intercrop of millet (1 row) and cowpea (1 row) with 0.5 m between rows (1Mx1C-0.50); T4 - intercrop of millet (1 row) and cowpea (1 row) with 0.75 m between rows (1Mx1C-0.75); and T5 - intercrop of millet (1 row) and cowpea (2 rows) with 0.5 m between rows (1Mx2C-0.50). The cowpea shoot dry weight, root dry weight, number and dry weight of nodules, grain yield and 1000-grain weight, and the millet fresh weight, shoot dry weight, grain yield and 1000-grain weight were evaluated. The land-use efficiency index (LUE) showed significant differences in yield bet...

A atividade de gases da atmosfera, principalmente os "Gases de Efeito Estufa" (GEE), como o vapor... more A atividade de gases da atmosfera, principalmente os "Gases de Efeito Estufa" (GEE), como o vapor d'água, o gás carbônico, o metano, os óxidos de nitrogênio e o ozônio, passou a ser objeto de estudos devido ao seu aumento, causando as mudanças climáticas globais, como o aumento da temperatura do ar, secas e outras. Além do gás carbônico, está havendo aumento da emissão de Compostos Orgânicos Voláteis (COV) na troposfera, além de óxidos de nitrogênio, que causam a produção de ozônio tóxico aos seres vivos. Este, o ozônio produzido em baixa altitude reduz a fotossíntese e produtividade de culturas sensíveis, como a soja e o algodão, culturas importantes no Brasil. O aumento substancial da concentração de gás carbônico na atmosfera, nos próximos anos, provavelmente causará aumento da fotossíntese e biomassa em plantas. Esse processo ocorrerá especialmente nas espécies arbóreas e gramíneas C 3 e menos nas leguminosas e plantas C 4. Entretanto, este aumento será menor que o previsto por estudos em ambiente controlado, segundo resultados de campo. Além disso, a maior concentração destes GEE na atmosfera causará aumento da temperatura do ar e redução da disponibilidade de água no solo, que podem anular o efeito benéfico e fertilizante do gás carbônico, especialmente quando associado ao efeito nocivo do aumento de ozônio na biosfera. Contudo, os estudos têm sido realizados em regiões temperadas, e pouco se sabe sobre a atividade do gás carbônico e ozônio, e seus efeitos sobre o metabolismo das plantas cultivadas, em regiões tropicais. Palavras-chave: biomassa, fotossíntese, gases de efeito estufa, ecofisiologia de plantas cultivadas. carbon metabolism of crops and the increase of atmospheric co 2 and o 3 : situation and previsions

In this study, we are presenting recommendations to the best agricultural use as well as for plan... more In this study, we are presenting recommendations to the best agricultural use as well as for plant breeding of three millet cultivars namely ENA1 and ENA2, which have African origin, and BRS1501 originally from India. These cultivars were evaluated for growth, yield and grain quality traits. The morphological traits evaluated in this study indicated that the African genotypes ENA1 and ENA2 are better than the Indian genotype BRS1501 for no-till farming or to produce forage with 15% of crude protein at flowering and at harvest to produce stover (around 7% of crude protein content) for livestock feeding. The BRS1501 cultivar exhibited the highest values for total crude protein, albumins and prolamins, phytate and mineral contents in grains. ENA1 and ENA2 exhibited the highest values of globulin and glutelin contents. The electrophoretic patterns for storage proteins were similar across the three millets cultivars, except for a higher intensity of two glutelin bands with 21 and 24 kDa in BRS1501. Together, the results allow us to recommend BRS1501 for grain production and ENA1 and ENA2 for biomass production.

Variation in tolerance in chilling-dependent photoinhibition has been associated with a wide rang... more Variation in tolerance in chilling-dependent photoinhibition has been associated with a wide range of traits in comparative physiological studies. A sweet corn (Zea mays L.) population of 214 F 2:3 families previously mapped to near-saturation with 93 RFLP DNA markers were subjected to low temperature and highlight events prior to measurement of the maximum dark-adapted quantum efficiency of PS II (F v /F m), to identify loci associated with variation in chilling-dependent photoinhibition. In the first assay with ten families varying in seedling growth and germination, significant differences were observed among families in their response to and recovery from exposure to high light at low temperature. All the 214 F 2:3 families from this population were then evaluated for tolerance of chilling-dependent photoinhibition in a controlled environment and then in three replicated trials in the field, each following naturally occurring chilling events during spring. The measured effects on F v /F m were analyzed with software that mapped segregating loci that regulate trait expression and linked to genetic markers (PLABQTL). QTL 3.096 (i.e. 96 cM on chromosome three) was consistently identified in both controlled environment and in the mean of the three field trails. Another QTL at 8.025, described the greatest percentage of total phenotypic variance (ca. 10%) for the mean reduction in F v /F m of all three periods of measurement in the field. A third QTL (4.136) showed a highly significant association in the third field trial. These three QTLs were closely associated with genes that have been mechanistically related to photoinhibition tolerance and repair. The results suggest that the ratio of F v /F m is an approach that may be used in establishing marker-assisted breeding for improved tolerance to chilling of maize in the light and in turn better earlyseason growth in cool temperate climates. Abbreviations: F v /F m-ratio of variable to maximal fluorescence of PS II; representing the dark-adapted maximum efficiency of PS II photochemistry; LOD-logarithm of the odds ratio, a measure of the probability of linkage; PPFD-photosynthetic photon flux density; QTL-quantitative trait loci; RFLPrestriction fragment length polymorphism

Pearl millet (Pennisetum glaucum) is a major staple food crop in the drier parts of the old world... more Pearl millet (Pennisetum glaucum) is a major staple food crop in the drier parts of the old world, like Africa and India. Recently, its cultivation became more widespread in no tillage crop farming systems in central Brazil, but it is also being used for cultivation during the dry season in other areas in Brazil. An emerging problem for the wider adoption of this crop in Brazil is the damage caused by the rust Puccinia substriata. This fungal disease is among the worst limitations for this crop worldwide. The rust occurring in Brazil was initially identified as the P. substriata var. penicillariae, but little information on the taxonomy and life-cycle of this rust is available in Brazil. The life-cycle of this rust variety remains somewhat obscure and the connection between the telial stage on pearl millet and the aecial stage on Solanaceae has never been experimentally demonstrated. Natural infection and inoculations under controlled conditions allowed for a complete description of all stages of this rust and the elucidation of its life-cycle, confirming that Solanum aethiopicum and Solanum melongena are aecial hosts. This coincidence for the alternate host and the limited and ambiguous morphological basis for the distinction of the varieties penicillariae and indica support the view that they are synonyms. Var. indica should be regarded as a late synonym of var. penicillariae.

or 39 DAS. The cultivar SC-90298823 had greater stomatal Genotype differences in gas exchange dur... more or 39 DAS. The cultivar SC-90298823 had greater stomatal Genotype differences in gas exchange during ontogeny and conductance at 39 DAS and a higher photosynthetic level than water stress responses at the vegetative and pollination stages the other lines. Stomata of Ouro negro remained partially were evaluated in four lines of Phaseolus 7ulgaris L. In the open during the water stress at the pollination stage (39 DAS) cultivar Carioca, net photosynthetic rate (A) and stomatal and supported a positive net photosynthetic rate (A). Differ-conductance (g s) were lower at the vegetative stage (20 days after sowing [DAS]) and maximum at the pollination stage (39 ences were also found between lines in intrinsic water use efficiency (IWUE) at 39 DAS, but not at 20 DAS. The DAS), followed by a decrease at the flowering stage (46 DAS) and a dramatic fall at the grain-filling stage (60 DAS). possibility of using IWUE at the pollination stage is discussed, in view of its use as one of the parameters for a drought Among the lines studied, the stomata of A320 closed faster than those of the other lines when water stress occurred at 20 tolerance breeding program in bean lines.

The predawn leaf water potential (C l), O 2 evolution (Ac) and stomatal conductance (g s) of thre... more The predawn leaf water potential (C l), O 2 evolution (Ac) and stomatal conductance (g s) of three bean genotypes growing in a greenhouse were evaluated in order to compare the effect of water stress induced at different ages, especially during reproductive ontogeny. There was a peak of Ac for all genotypes 30 days after sowing (DAS) at the pollination stage, and the greatest effects of drought on this parameter occurred at this stage, with a decline in Ac from a higher C l (−0.35 MPa) than at the other stages (below − 1.0 MPa). The C l and final yield were also more reduced when drought was imposed at the pollination and flowering stages than at the vegetative or pod filling stages. During water stress, the g s of the genotypes was reduced by drought, but Ouro negro showed a different behavior in its stomatal control under drought. Firstly, with water deficit imposition, it maintained a higher g s level in the morning (9:00 h), when the vapor pressure deficit is the lowest of the day, than at midday (12:00 h) and in the afternoon (15:00 h). Secondly, after rehydration, this genotype had a higher g s than non stressed plants.