Germinação e formação de mudas de coqueiro irrigadas com águas salinas Germination and seedling formation of coconut irrigated with saline waters

O cultivo de coqueiro vem crescendo no Nordeste, com aumento de produtividade, quando irrigado. Sendo comuns na região águas salinas e se considerando a carência de dados de pesquisa de salinidade em coqueiro anão-verde (Cocos nucifera L.), objetivou-se, através deste trabalho, avaliar os efeitos da irrigação com águas salinas (CEa = 2,2, 5, 10, 15 e 20 dS m-1) sobre a germinação e o crescimento inicial de plântulas, até 120 dias após semeadura (fase I), estendendo-se a avaliação, posteriormente, após repicagem para o viveiro, quando passaram a ser irrigadas com água de CEa = 2,2 dS m-1, durante 120 dias (fase II), estudando-se o efeito residual dos níveis de salinidade aplicados na fase I. Em ambos os experimentos, o delineamento foi inteiramente casualizado, com quatro repetições. As águas salinas foram preparadas com adição de NaCl comercial. Na primeira fase, o incremento da CEa não influenciou significativamente a germinação que variou de 80 a 97,5%, porém afetou a velocidade de germinação e o crescimento das plântulas; na fase de sementeira, a salinidade afetou a fitomassa total a partir de 5,4 dS m-1; o sistema radicular foi a variável mais afetada pela salinidade. Na fase II, as plantas oriundas de germinação sob condições de alta salinidade, após passarem a ser irrigadas com água de 2,2 dS m-1, cresceram no mesmo ritmo daquelas germinadas sem estresse salino.<br>The coconut cultivation is growing in the Northeast Brazil with increase in productivity under irrigated conditions. Saline waters are commonly found in this region and considering the lack of data related to salinity on dwarf-green coconut (Cocos nucifera L.), this work had the objective of evaluating the effects of the irrigation with saline waters (ECw = 2.2, 5, 10, 15 and 20 dS m-1) on the germination and the initial growth of seedlings until 120 days after sowing (phase I), extending the evaluation, later, after transplanting in the nursery, when seedlings were irrigated with water of ECw = 2.2 dS m-1, for another 120 days (phase II), studying the residual effect of the applied salinity levels in the phase I. In both the experiments a completely randomized design was used with four replications. The saline waters were prepared with the addition of commercial NaCl. In the first phase, the increment of ECw did not influence the germination significantly, which varied from 80 to 97.5%, however, it affected the germination speed and the growth of the seedlings; in the germination phase the salinity affected the total phytomass starting from 5.4 dS m-1; the root system was the most affected variable by the water salinity. In the phase II, the plants germinated under conditions of high salinity when irrigated with water of 2.2 dS m-1 maintained the rhythm of growth similar to those germinated without saline stress

DIII-D research advancing the physics basis for optimizing the tokamak approach to fusion energy

Funding Information: This material is based upon work supported by the US Department of Energy, Office of Science, Office of Fusion Energy Sciences, using the DIII-D National Fusion Facility, a DOE Office of Science user facility, under Awards DE-FC02-04ER54698 and DE-AC52-07NA27344. Publisher Copyright: © 2022 IAEA, Vienna.DIII-D physics research addresses critical challenges for the operation of ITER and the next generation of fusion energy devices. This is done through a focus on innovations to provide solutions for high performance long pulse operation, coupled with fundamental plasma physics understanding and model validation, to drive scenario development by integrating high performance core and boundary plasmas. Substantial increases in off-axis current drive efficiency from an innovative top launch system for EC power, and in pressure broadening for Alfven eigenmode control from a co-/counter-I p steerable off-axis neutral beam, all improve the prospects for optimization of future long pulse/steady state high performance tokamak operation. Fundamental studies into the modes that drive the evolution of the pedestal pressure profile and electron vs ion heat flux validate predictive models of pedestal recovery after ELMs. Understanding the physics mechanisms of ELM control and density pumpout by 3D magnetic perturbation fields leads to confident predictions for ITER and future devices. Validated modeling of high-Z shattered pellet injection for disruption mitigation, runaway electron dissipation, and techniques for disruption prediction and avoidance including machine learning, give confidence in handling disruptivity for future devices. For the non-nuclear phase of ITER, two actuators are identified to lower the L-H threshold power in hydrogen plasmas. With this physics understanding and suite of capabilities, a high poloidal beta optimized-core scenario with an internal transport barrier that projects nearly to Q = 10 in ITER at ∼8 MA was coupled to a detached divertor, and a near super H-mode optimized-pedestal scenario with co-I p beam injection was coupled to a radiative divertor. The hybrid core scenario was achieved directly, without the need for anomalous current diffusion, using off-axis current drive actuators. Also, a controller to assess proximity to stability limits and regulate β N in the ITER baseline scenario, based on plasma response to probing 3D fields, was demonstrated. Finally, innovative tokamak operation using a negative triangularity shape showed many attractive features for future pilot plant operation.Peer reviewe