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 F305.

No abstract

Meloidogyne enterolobii has severely compromised the main guava producing regions in Brazil, thereby stimulating the development of resistant varieties for efficient management of this nematode. This study aimed to assess the penetration, development, reproduction, and induced cellular responses of M. enterolobii in roots of four species of the genus Psidium (P. guajava‘Paluma’, P. guineense, P. cattleyanum, and P. friedrichstalianum) from the Active Germplasm Bank (BAG) of the Center for Agricultural Research of the Semi-arid Tropics (Embrapa Semi-arid) located in Petrolina, PE, Brazil. Three experiments were carried out to assess the penetration, development, and reproduction of the nematode and, subsequently, histological analyses were performed. Nematode penetrated indistinctly in both resistant and susceptible species, but only in ‘Paluma’ an evolution was observed from vermiform juveniles to “sausage” and globose forms in experiment 1. In experiment 2, all species presented “sausage” forms of nematode, but only in ‘Paluma’, these forms reached adult female stages. In experiment 3, only ‘Paluma’ was susceptible to M. enterolobii, with reproduction factor above unity. Histological analyses showed that, except for P. guajava, the other Psidium species presented poorly developed feeding sites at 20 days after inoculation.