ABSTRACT Despite the great economic importance of yerba mate (Ilex paraguariensis A. St.-Hil.), information about clonal plantations and planting conditions of this tree is still scarce. Thus, we evaluated initial field establishment of five clonal yerba mate cultivars, planted at three seasons of the year (summer, autumn, and spring) in a shaded environment, and in the autumn, we also established blocks in a full sunlight environment, to compare both cultivation environments. We evaluated plants at 3, 6, 9, and 12 months after planting, counting the surviving plants, shoots number, and measuring height and canopy diameter. At 12 months we also analyzed the caffeoylquinic acids (CQA) contents in mature leaves from different environments. Plant survival and growth were not affected by planting seasons. Cultivars Aupaba and BRS 409 had the highest survival rates in all seasons evaluated. The shaded environment provided greater survival and growth than full sunlight, also showing higher CQA levels in the leaves. Clonal cultivars Aupaba, BRS 408, and BRS 409 presented higher growth in both environments. The severe drought in the first year may have affected survival; however, growth was considered satisfactory and plants’ initial establishment was better in the shaded environment. Ilex A St.Hil., StHil St. Hil. , St Hil St.-Hil.) scarce Thus summer, summer (summer autumn spring environments 3 6 9 1 number diameter (CQA 40 408 however St.Hil. St.-Hil. 4 St.Hil St.-Hil

Abstract The success of seedlings establishment for commercial planting and forest restoration depends on the availability of nutrients during seedlings production. The objective was to evaluate the efficiency in controlled-release fertilizer use in Cordyline spectabilis seedlings production and what is the additional cost per seedling produced. Seedling production was performed with doses of 0.0 (control); 2.5; 5.0; 7.5; 10.0 and 12.5 kg m-³ of Basacote® Plus 9M (16-08-12) controlled-release fertilizer added to the substrate. The experiment was placed in a greenhouse and we evaluated morphological parameters to determine seedlings growth. The dose of 10.7 kg m-3 provided a greater number of leaves (11.4) and leaf length (24.9 cm), higher values of shoot (4.64 g), root (2.32 g) and shoot root ratio (1.99) were obtained above 10.7 kg m-3 fertilizer. We recommend the use of 10.7 kg m-3 controlled-release fertilizer for seedlings production with an increase of R$ 0.05 per seedling produced.

Resumo A adição de polímeros hidroretentores visa aumentar a capacidade de retenção de água no solo, propiciando maior taxa de sobrevivência das mudas e permitindo o plantio em épocas distintas do ano. O objetivo do presente estudo foi avaliar o efeito do uso do hidrogel no plantio de mudas de Eucalyptus dunnii em vasos, relacionado com diferentes manejos hídricos, simulando condições de campo em solo do tipo Cambissolo Húmico. O experimento foi conduzido em delineamento inteiramente casualizado, com arranjo fatorial (hidrogel e frequência de irrigação). O fator hidrogel foi composto por presença ou ausência do polímero, e a frequência de irrigação por irrigação somente no plantio, a cada 8 dias, 4 dias e diariamente. Foram realizadas avaliações da sintomatologia do estresse hídrico, aspectos morfométricos, teor de água no solo e trocas gasosas. O hidrogel proporcionou aumento no teor de água no solo e o adiamento nos sintomas de estresse hídrico, principalmente quando a irrigação foi efetuada com menor frequência. A adição do polímero também proporcionou melhoria na qualidade das mudas, com maior acúmulo de massa seca. O estresse hídrico foi um fator limitante para a abertura estomática. Quanto menor a disponibilidade de água, menores foram os valores de fotossíntese, condutância estomática e transpiração. Em geral, os resultados obtidos confirmam que a adição de hidrogel no solo otimiza a disponibilidade de água, com possibilidade de redução da mortalidade no plantio e maximização do crescimento das plantas na fase inicial de estabelecimento.

Abstract The addition of water-repelling polymers aims to increase water retention capacity in the soil, providing higher seedling survival rate and allowing planting at different times of the year. The objective of the present work was to evaluate the effect of hydrogel use on planting Eucalyptus dunnii seedlings in pots, related to different water management, simulating field conditions in a Humic Cambisol soil. The experiment was conducted in a completely randomized design with factorial arrangement (hydrogel and irrigation frequency). The hydrogel factor was composed by the presence or absence of the polymer, and the frequency of irrigation by irrigation only at planting, every 8 days, 4 days and daily. Water stress symptomatology, morphometric aspects, soil water content and gas exchange were evaluated. The hydrogel provided an increase in soil water content and delayed symptoms of water stress, especially when irrigation was less frequent. The addition of the polymer also provided improved seedling quality, more accumulated dry mass. Water stress was a limiting factor for stomatal opening. The lower the water availability, the lower the photosynthesis, stomatal conductance and transpiration values. In general, the results confirm that the addition of hydrogel in the soil optimizes water availability, with the possibility of reducing planting mortality and maximizing plant growth in the initial phase of establishment.