The objective of this work was to evaluate the survival and initial growth, in the field, of eucalyptus seedlings produced in different substrates. Eucalyptus benthamii seedlings produced in 36 substrates were evaluated in the field. The substrates consisted of mixtures, at different volumetric proportions, of: carbonized rice husk, charcoal with granulometry between 1.0-3.0 mm, charcoal with granulometry between 3.0-5.0 mm, coconut fiber, semi-decomposed pine bark, fine vermiculite, sewage sludge, and peat moss. At 1, 2, 3, 6, 12, 18, and 24 months after planting, survival, height, and diameter were determined. At 24 months after planting, height increment, diameter increment, transversal area, and basal area were also measured. The seedlings that showed 100% survival after 24 months under field conditions were those grown in the nursery in substrates with a higher proportion of fine vermiculite, sewage sludge, and peat moss, that is, in substrates with a higher microporosity. However, there is no effect of substrate characteristics on seedling initial growth in the field. A significant correlation is observed between the survival of seedlings at 6 months and their diameter at the end of the nursery period, evidencing the importance of this characteristic for the establishment of the plant in the field, regardless of the used substrate.

The objective of this work was to evaluate the bioactive compounds and foliar anatomy of yerba mate (Ilex paraguariensis) morphotypes. The antioxidant capacity, total phenolic compounds, methylxanthines, and caffeoylquinic acids were determined from the aqueous extract of leaves of the following yerba mate morphotypes: “sassafras”, dark green, dull green, gray, and “peludinha”. Light microscopy and scanning electron microscopy were used to observe the anatomical differentiations. The dark-green morphotype showed the highest contents of caffeine (20.4 mg g-1), differing significantly only from the “peludinha” morphotype (8.8 mg g-1). All morphotypes showed similar and high antioxidant activity (886.0 and 588.1 μmol Trolox equivalent antioxidant activity per gram of sample for ABTS and DPPH, respectively), as well as high total phenolic compounds content (73.9 mg gallic acid equivalent per gram of sample). Although the anatomy of the leaf mesophyll is similar, the wax deposition and cuticle striation configuration on the adaxial surface differ between all five morphotypes.

Research Highlights: The mean leaf angle and crown projection area can be used as criteria for grouping tree seedling species in different irrigation zones in tree nurseries with overhead microsprinkler systems, preventing water and fertilizer waste, and increasing growth. Background and Objectives: There are important gaps in current functional knowledge about how plant architecture, especially the mean leaf angles of tree seedlings, affect water and nutrient solution capture in overhead microsprinkler systems. These gaps contribute to water and fertilizer waste in tree nurseries. This research aimed to ascertain how mean leaf angles affect irrigation water capture, leaching, and the growth of tree seedlings given different volumes of irrigation. Materials and Methods: Nine species of tree seedlings with different mean leaf angles were submitted to four irrigation volumes (8, 10, 12, and 14 mm) applied daily by overhead microsprinklers in a split-plot design completely randomized. The variables leaching fraction, height, stem diameter, shoot, root, and total dry mass, Dickson quality index, crown projection area, root system quality, and leachate electrical conductivity were evaluated. Results: For species with mean leaf angles of −54, 31, 38, 42, 55, 57, and 58°, the 8 mm irrigation volume was sufficient to produce greater growth and less leaching. For species with angles of −56 and −14°, the 14 mm irrigation volume was required to produce greater growth. Conclusions: The tree seedling species with positive mean leaf angles facilitate irrigation water and nutrient solution capture, allowing the application of lower irrigation volume. On the other hand, some tree seedling species with negative mean leaf angles hinder irrigation water and nutrient solution capture, requiring the application of higher irrigation volume. When the tree seedling species have a negative mean leaf angle, but the crown projection area is small, the difficulty of water and nutrient solution reaches directly the substrate is attenuated.

Yerba mate (Ilex paraguariensis A. St.-Hil.) is a South American tree cultivated in systems with or without shading at different intensities; however, there is no consensus about shading effect on leaf biomass production. Therefore, we evaluated yerba mate clones under different shading levels over one year to determine the influence of shading and genotype on biomass production. Two yerba mate genotypes (EC22 and EC40), cultivated in a semi-hydroponic system, were subjected to five shading levels (0%, 40%, 51%, 76%, and 82%) in a greenhouse. We determined total fresh biomass (branches and leaves) and fresh biomass of young and mature leaves on six harvests. Biomass production was influenced by harvest season, genotype, and shading levels. Spring and summer harvests provided higher biomass production than the other seasons. EC40 genotype produced higher total fresh and young leaf biomass than EC22. Although we observed differences among genotypes and harvest seasons, shading was the factor that most influenced biomass production. Total fresh biomass productivity was reduced 6.8 times between 0% and 82% shading for the EC40 genotype. Thus, we do not recommend high levels of shade, such as 76% and 82%, in this new yerba mate cultivation system. In this study we demonstrated that yerba mate biomass production is influenced by shading levels, harvest seasons, and genotypes. Summer and spring favored biomass production, probably because of high temperatures and solar irradiation. The EC40 genotype had higher biomass production than EC22. Shade at any level reduced yerba mate biomass productivity, and we do not recommend 76% and 82% shade in species cultivation. This study with yerba mate clones clarified issues related to shading effects on biomass production. The semi-hydroponic system proved to be viable for yerba mate cultivation, with high biomass productivity, especially young leaves.

This study aimed to evaluate the effect of substrates made of composted sewage sludge and irrigation depths on the growth and quality of E. grandis x E. urophylla cuttings to optimize water management for each substrate. The substrates were obtained from sewage sludge composted with sugarcane bagasse or Eucalyptus bark, namely: composted sewage sludge with sugarcane bagasse (1:3 v:v); sewage sludge composted with Eucalyptus bark (1:3 v:v) and a mixture of both substrates in a volumetric proportion 2:1 (v:v). Commercial substrate composed of Sphagnum peat, vermiculite and rice husk (3:1:1 v:v: v) was used as a control. The irrigation depths tested were 11, 14 and 17 mm, applied in two daily applications. The substrates were physically and chemically characterized and height, stem diameter, shoot, root and total dry mass, Dickson quality index and root system conformation were measured to determine the growth and quality of seedlings. The substrates obtained through the composting of sewage sludge with sugarcane bagasse or Eucalyptus bark are fit for producing Eucalyptus cuttings, however, the water specificity of each substrate must be considered. Although an 11mm irrigation depth is indicted for the mixture of both substrates (2:1 v:v), a 17mm irrigation depth is needed for the sewage sludge composted with sugarcane bagasse (1:3 v:v) substrate.

Ilex paraguariensis is an important forest species in Brazil. Recently, the development of new products has increased seedlings demand and consequently, the interest in new products to use as substrates like residues from industries. We aimed to evaluate the viability of using industrial residues as substrates to produce yerba mate seedlings. We formulated thirteen substrates with coconut fiber, carbonized and decomposed yerba mate industrial residues in different ratios, which were compared to two commercial substrates, in a completely randomized design. The stratified seeds were placed in 110 cm³ tubes filled with the substrates. Plants were kept in a greenhouse for 135 days, shade house (70%) for 30 days, and rustification area in full sunlight for 15 days, under fertigation after 30 days of sowing. We evaluated montlhy the survival, height, and stem diameter, and at the end of the production period, we evaluated shoot and root dry mass. From the data obtained, we calculated the total dry mass and ‘Dickson quality index’. The substrates formulated with coconut fiber and decomposed yerba mate industrial residue can be used to produce yerba mate seedlings, but it depends on the ratio of the substrate components. Substrates with higher total porosity and microporosity provided seedlings with biometric characteristics similar to those produced in commercial substrates. The carbonized yerba mate residue reduced seedling growth when used in a percentage equal to or higher than 50% in the substrate.