Crescimento de variedades de sorgo forrageiro submetido a frações de lixiviações com efluente salino da piscicultura.

O objetivo do presente trabalho foi avaliar o crescimento de variedades de sorgo forrageiro submetidos a diferentes frações de lixiviação com efluente salino da piscicultura. O experimento foi implantado no Campo Experimental Caatinga, pertencente a Embrapa Semiárido. Foi adotado o delineamento experimental em blocos ao acaso, com quatro blocos, em arranjo fatorial 3 x 4, composto por três variedades de sorgo forrageiro: Volumax, F305 e Sudão; e quatro frações de lixiviação: 0, 5, 10 e 15%, com uso de efluente salino proveniente da piscicultura. Foram avaliadas periodicamente a altura e área foliar total das plantas. As maiores frações de lixiviação proporcionaram plantas mais altas e com maiores valores de área foliar total

Antioxidant defenses of irrigated forage sorghum with saline aquaculture effluent.

The objective of this work was to evaluate the biomass production and antioxidant enzymatic system activity of irrigated forage sorghum with saline aquaculture effluent under different leaching fractions. The experiment was conducted in the Caatinga Experimental Field of the Embrapa Semiarido, in Petrolina, State of Pernambuco, Brazil. The experimental design was a complete randomized block in a split-plot arrangement with four replications, consisting of three forage sorghum varieties (Volumax, F305 and Sudan) and four leaching fractions (0, 5, 10 and 15%). The vegetal materials were collected when the plants were at the soft-dough stage. The biomass production and activity of the enzymes superoxide dismutase, catalase and ascorbate peroxidase were evaluated. Irrigation with saline aquaculture effluent with leaching fraction of 15% results in low salinity level in the root zone and higher biomass production of forage sorghum Sudan and F305, in semiarid conditions. The antioxidant system was activated in the three sorghum varieties to prevent accumulation of reactive oxygen species, with the synchrony between the enzymes superoxide dismutase and catalase resulting in a better productive response of the varieties Sudan and F30

Salinity decreases transpiration of sorghum plants.

Growing in a saline environment causes changes in important physiological processes that are directly related to plant growth and development. In this study we evaluated the effect of salinity on transpiration of sorghum plants in semi-arid conditions and found that the highest rates of transpiration were observed in the hottest hours of the day, between 10 a.m. and 3 p.m., with plants subjected to the saline environment having their transpiration reduced by up to 70% when compared to the non-saline environment. This behavior can be reflected in reductions in plant growth and development due to reduced water absorption by the roots, consequently causing an imbalance of nutrients in the plant due to low absorption rate and competition between nutrients and salts in the preferred routes of absorption in the roots

Gas exchange and enzymatic metabolism in grain sorghum varieties irrigated with saline water.

The objective of this study was to evaluate the effect of irrigation water salinity on gas exchange and antioxidative system responses of grain sorghum varieties. An experiment was conducted in a greenhouse located at the headquarters of Embrapa Semiarid Agriculture, Petrolina-PE, Brazil. The experimental design was randomized blocks, in a 6 x 5 factorial scheme. Six varieties of grain sorghum irrigated with saline water with five levels of salinity were evaluated. Photosynthesis and transpiration rate, stomatal conductance, leaf temperature, intrinsic and instantaneous water use efficiency, relative water content and leaf turgor potential were evaluated, as well as the activity of the enzymes catalase, ascorbate peroxidase and superoxide dismutase, and shoot biomass production. It was observed that irrigation with saline water causes reduction in the gas exchange and water status of grain sorghum varieties. The antioxidative system was activated in the six sorghum varieties to avoid the accumulation of reactive oxygen species, and the synchronism between the enzymes led to a better response of shoot dry mass production of the Ponta Negra variety

Respostas de crescimento e fisiologia de variedades de sorgo submetidas a estresse salino.

O efeito da salinidade sobre a fisiologia do sorgo está diretamente relacionado com a interferência dos sais nos processos fotossintéticos, dessa forma a avaliação de trocas gasosas vem sendo um passo importante para compreender o efeito dos sais nas plantas. Com isto, este estudo teve o objetivo de avaliar o efeito da salinidade nas trocas gasosas e características biométricas de variedades de sorgo granífero. O experimento foi realizado em casa de vegetação localizada na sede da Embrapa Semiárido, Petrolina-PE. O delineamento experimental utilizado foi em blocos casualizados dispostos em esquema fatorial 6 X 5, considerando seis variedades de sorgo (1011-IPA, 2502-IPA, 2564-IPA, 2600-IPA, Ponta Negra e Qualimax) e cinco níveis de água salina (0; 1,5; 3,0; 6,0 e 12,0 dS m-1). As sementes foram semeadas em vasos com capacidade para 20 litros e irrigadas a cada dois dias, mantendo-se uma fração de lixiviação de aproximadamente 15%. Após quarenta e cinco dias foram avaliadas as trocas gasosas, com o Analisador Portátil de Gás Infravermelho (IRGA), modelo Li-6400, utilizando luz artificial fixada em 2500 ?mol m-2 s-1 e os parâmetros biométricos altura da planta, diâmetro do colmo e número de folhas verdes. Pode-se observar que, independentemente da variedade, houve reduções significativas nos parâmetros fotossintéticos e biométricos avaliados

Crescimento e produção do sorgo granífero, var. 1011-IPA, submetido a níveis de salinidade.

Este trabalho teve como objetivo avaliar o efeito de diferentes níveis de salinidade sobre o crescimento e produção de sorgog granífero, var. 1011-IPA