Sensibilidade do clorofilômetro para diagnóstico nutricional de nitrogênio no milho Sensitivity of the chlorophyll meter for nutritional diagnostic of nitrogen in corn (Zea mays L.)

A obtenção de altas produtividades de milho (Zea mays L.) torna-se difícil, dentre outros fatores, pela complexa quantificação dos requerimentos de nitrogênio (N) da cultura do milho ao longo do seu ciclo, o que dificulta o seu dimensionamento, ainda mais, considerando a variada capacidade de suprimento de N em solos brasileiros. Nesse sentido, os teores relativos de clorofila surgem como uma opção para o manejo do N. Objetivou-se, neste estudo avaliar a sensibilidade do clorofilômetro em indicar o estado nutricional do milho em resposta ao N, em solos com teores de argila contrastantes e sob diferentes condições de suprimento de N. Para isso, foram realizados experimentos em condições controladas e de lavoura. Em condições controladas, foram testados três solos com teores de argila contrastantes e cinco doses de N, sendo avaliados, aos 55 dias após a emergência (estádio prévio ao VT), os teores relativos de clorofila, de N foliar e a produção de matéria seca da parte aérea. Em condições de lavoura foram avaliados seis tratamentos, resultantes da combinação de três doses de nitrogênio em cobertura, na presença e ausência de calcário, sendo a maior dose de N correspondente à condição na qual não haveria limitação de disponibilidade quanto ao suprimento do nutriente. A nutrição nitrogenada foi monitorada semanalmente com uso do clorofilômetro. Foram avaliados também os teores de N na folha e no grão, o N mineral no solo, a matéria seca da parte aérea e a produtividade de grãos. Os resultados permitiram concluir que há sensibilidade do clorofilômetro em detectar diferenças no estado nutricional do milho em resposta a diferentes características de solo e de suprimento de N, servindo como indicador da necessidade de adubação nitrogenada de cobertura.<br>High corn yields are conditioned by the different factors involved in the quantification of nitrogen requirements for the crop throughout its cycle, which becomes difficult considering the varying capacity of Brazilian soils to supply N. In this sense, the relative contents of chlorophyll are a tool which helps to improve soil N management. The study aimed to evaluate the sensitivity of the chlorophyll meter to predict the nutrient status of corn in response to N applied in the soil with contracting clay contents and under different conditions of N supply. To that end, experiments were carried out under both controlled and field conditions. Under controlled conditions, three soils with contracting clay contents and five doses of N were tested. 55 days after emergence (before the VT period), the relative contents of chlorophyll, leaf N and the weight of the dry matter of the shoot were evaluated. Under crop conditions, six treatments, resulting from the combination of three doses of nitrogen topdressing, in the presence and absence of limestone, were evaluated, the highest dose of N corresponding to the ideal condition of N supply for corn. Nitrogen nutrition was monitored weekly with a chlorophyll meter. The contents of N in leaf, in grain, mineral N in soil, shoot dry matter and grain yield were also evaluated. The results allow concluding that there is a sensitivity of the chlorophyll meter to detect differences in the nutritional status of corn in response to different characteristics of soil and N supply, acting as an indicator of the need for nitrogen topdressing

Standardizing Definitions of Hematopoietic Recovery, Graft Rejection, Graft Failure, Poor Graft Function, and Donor Chimerism in Allogeneic Hematopoietic Cell Transplantation : A Report on Behalf of the American Society for Transplantation and Cellular Therapy

Allogeneic hematopoietic cell transplantation (allo-HCT) is potentially curative for certain hematologic malignancies and nonmalignant diseases. The field of allo-HCT has witnessed significant advances, including broadening indications for transplantation, availability of alternative donor sources, less toxic preparative regimens, new cell manipulation techniques, and novel GVHD prevention methods, all of which have expanded the applicability of the procedure. These advances have led to clinical practice conundrums when applying traditional definitions of hematopoietic recovery, graft rejection, graft failure, poor graft function, and donor chimerism, because these may vary based on donor type, cell source, cell dose, primary disease, graft-versus-host disease (GVHD) prophylaxis, and conditioning intensity, among other variables. To address these contemporary challenges, we surveyed a panel of allo-HCT experts in an attempt to standardize these definitions. We analyzed survey responses from adult and pediatric transplantation physicians separately. Consensus was achieved for definitions of neutrophil and platelet recovery, graft rejection, graft failure, poor graft function, and donor chimerism, but not for delayed engraftment. Here we highlight the complexities associated with the management of mixed donor chimerism in malignant and nonmalignant hematologic diseases, which remains an area for future research. We recognize that there are multiple other specific, and at times complex, clinical scenarios for which clinical management must be individualized

Standardizing Definitions of Hematopoietic Recovery, Graft Rejection, Graft Failure, Poor Graft Function, and Donor Chimerism in Allogeneic Hematopoietic Cell Transplantation: A Report on Behalf of the American Society for Transplantation and Cellular Therapy.

Allogeneic hematopoietic cell transplantation (allo-HCT) is potentially curative for certain hematologic malignancies and nonmalignant diseases. The field of allo-HCT has witnessed significant advances, including broadening indications for transplantation, availability of alternative donor sources, less toxic preparative regimens, new cell manipulation techniques, and novel GVHD prevention methods, all of which have expanded the applicability of the procedure. These advances have led to clinical practice conundrums when applying traditional definitions of hematopoietic recovery, graft rejection, graft failure, poor graft function, and donor chimerism, because these may vary based on donor type, cell source, cell dose, primary disease, graft-versus-host disease (GVHD) prophylaxis, and conditioning intensity, among other variables. To address these contemporary challenges, we surveyed a panel of allo-HCT experts in an attempt to standardize these definitions. We analyzed survey responses from adult and pediatric transplantation physicians separately. Consensus was achieved for definitions of neutrophil and platelet recovery, graft rejection, graft failure, poor graft function, and donor chimerism, but not for delayed engraftment. Here we highlight the complexities associated with the management of mixed donor chimerism in malignant and nonmalignant hematologic diseases, which remains an area for future research. We recognize that there are multiple other specific, and at times complex, clinical scenarios for which clinical management must be individualized