In this research it was hypothesized that Campomanesia xanthocarpa can overcome some level of water deficiency by adjusting physiological parameters and that shading minimizes the water deficit effects while maintaining elevated photosynthetic rates and relative water content of the leaves and makes a resumption of metabolism and growth when the water supply is normalized. The seedlings were submitted to two water regimes (continuous irrigation - CI and intermittent irrigation - II), three shading percentages (0, 30 and 70%) and six evaluation times (Start - T0, 1st Photosynthesis Zero - 1st P0, 1st Recovery - 1st REC, 2nd Photosynthesis Zero - 2nd P0, 2nd Recovery - 2nd REC and END). Plants under water deficit at 0% shading led to a reduction in photosynthetic metabolism, relative water content (RWC), leaf area, number of leaves, and height, especially during the stress periods 1st and 2nd P0. The 30 and 70% shading mitigated the stressful effect of water deficit on C. xanthocarpa seedlings. The results did not confirm the hypothesis that C. xanthocarpa seedlings are intolerant to water deficit since, although sensitive, they presented a potential for recovery of photosynthetic and growth characteristics under all cultivation conditions. It was concluded that that shading minimizes the stressful effects of water deficit.

The objective of this study was to evaluate the activity of antioxidant enzymes, the functioning of the photosystem II and quality of C. xanthocarpa seedlings cultivated under intermittent water deficit and shading levels and the influence of shading on recovery potential after suspension of the stress conditions. The seedlings were subjected to three levels of shading (0, 30, and 70%), six periods of evaluation (start: 0 days; 1st and 2nd photosynthesis zero: 1st and 2nd P0; 1st and 2nd recovery: 1stand 2nd REC; and END), and two forms of irrigation (control: periodically irrigated to maintain 70% substrate water retention capacity, and intermittent irrigation: suspension of irrigation). The plants subjected to intermittent irrigation conditions at 0% shading showed a reduction in water potential (Ψw) and potential quantum efficiency of photosystem II (Fv/Fm) and maximum efficiency of the photochemical process (Fv/F0) and an increase in basal quantum production of the non-photochemical processes (F0/Fm). Superoxide dismutase (SOD) activity was higher in the leaves than in the roots. The C. xanthocarpa is a species sensitive to water deficit but presents strategies to adapt to an environment under temporary water restriction, which are more temporary are most efficient under shading. The seedlings with water deficit at all levels of shading exhibited higher protective antioxidant activity and lower quality at 0% shading. The shading minimizes prevents permanent damage to the photosystem II and after the re-irrigation, the evaluated characteristics showed recovery with respect to the control group, except POD and SOD activities in the leaves.

Com a premissa de que a utilização de hidrogel associado à calagem e adubação em plantios de eucalipto aumenta a retenção de água e o teor de nutrientes no solo, objetivou-se avaliar a sobrevivência e o desenvolvimento inicial de clones híbridos de Eucalyptus grandis x Eucalyptus camaldulensis, em função da utilização de hidrogel, calagem e adubação. Em um Argissolo Vermelho, foram dispostos os tratamentos: 1) controle, 2) hidrogel, 3) adubação convencional, 4) adubação + calagem, 5) adubação + hidrogel e 6) adubação + calagem + hidrogel. Foi utilizado o delineamento em blocos casualizados, com seis repetições e seis plantas por parcela. Avaliou-se a sobrevivência, a altura, o diâmetro do caule, o teor de macronutrientes na parte aérea e atributos químicos do solo. O tratamento adubação + hidrogel proporcionou maior altura e diâmetro aos 240 dias após o transplante. Contudo, a sobrevivência foi maior no tratamento com adubação convencional. Os resultados indicam a viabilidade do uso de hidrogel. Porém, mais estudos devem ser realizados para comprovação de seus efeitos e recomendação de dosagens adequadas.Hydrogel, liming and fertilizing in early development, survival and nutritional composition of eucalyptus hybrid plantsWith the premise that use of hydrogel associated with liming and fertilization in eucalyptus plantations increases water retention and nutrient content in the soil, this work aimed to evaluate the survival and early development of the hybrid Eucalyptus grandis x Eucalyptus camaldulensis when using hydrogel, liming and fertilization. In Ultisol, the treatments were: 1) control, 2) hydrogel, 3) conventional fertilization, 4) fertilizer + lime, 5) fertilizer + hydrogel and 6) fertilizer + lime + hydrogel. The treatments were arranged in a randomized block design, with six replications and six plants per plot. We evaluated height, diameter, survival, macronutrient content in shoot and soil chemical properties. The hydrogel + fertilization treatment provided bigger height and diameter at 240 days after transplant, however, the survival was higher in fertilization treatment. The results indicate the viability of the hydrogel use. However but more studies are needed to prove its effects and recommendation of appropriate dosages.Index terms: Initial growth; Nutritional evaluation; Hidroretentor gel

The industries of cellulose and paper have generated large amounts of solid waste and effluents which have been used as soil conditioners and source of nutrients to improve physical and chemical attributes of areas growing forest species. This study analyzes the spatial and temporal variability of Eucalyptus urograndis regarding the chemical attributes of soil treated with cellulose residue. The fertilization of an experimental area in the Três Lagoas county used a lime sludge/Oxyfertil ® compound with a 2 ha. experimental grid containing 50 sampling points set up over it. Plant and soil samples were collected during three consecutive years