This study evaluated the effect of using hydrogel in the planting of Eucalyptus dunnii seedlings in pots, under different water-management regimens. Seedlings of approximately 25 cm height were planted in pots filled with 4.5 L of soil. The experiment was of Completely Randomized Design, in a 2x3 factorial, with absence and presence of hydrogel related to different water-management regimens (irrigation only in planting, every 3 to 6 days). From planting until the 47th day the seedlings were evaluated for the symptoms of water stress, chlorophyll content and gas exchange. Finally, the development of the plants was evaluated using the root dry weights and shoots, as well as by determining the water retention curve. As a result, the use of the polymer yielded an increase in water retention and a delay in the symptoms of drought stress, consequently increasing chlorophyll levels. One can observe the direct effect gas exchange of this kind, where recovery of the variables analyzed 24 h after irrigation was visible. Reviews of dry biomass demonstrated that treatment with the use of hydrogel showed the best development. However, the use of hydro retainer polymer increased the quality of Eucalyptus dunnii seedlings, besides being an alternative planting method in dry periods of the year.

O protagonismo das mulheres em viveiros florestais The protagonism of women in forest nurseries

No abstract

In view of the increasing expansion of the use of wood and non-timber products from the Eucalyptus genus, the identification and impact caused by the salinity of Brazilian soils in the development and growth of the species are of fundamental importance for a better utilization of salinized areas in the country. In order to contribute to the understanding of this problem, the present work evaluated the effect of different levels of salinity (brackish water) on gas exchange in Eucalyptus camaldulensis Dehnh plants. The levels analyzed were: 0, 50, 100, 200, 400 µM NaCl. A completely randomized design with 10 replicates (plants) was used, in which the gaseous exchanges were evaluated with the aid of a portable photosynthesis meter (IRGA), determined the values of photosynthesis (A), stomatal conductance (gs), rate transpiration (E), the relation between the intercellular and atmospheric concentration of CO² (Ci / Ca) and water use efficiency (WUE). Initially the seedlings did not undergo physiological changes, showing a certain tolerance of the species to high levels of salinity. Reduction in gas exchanges was only more noticeable after reapplication of the salt (after 7 days). Due to the results obtained, high tolerance of the species to salinity is observed.