Rubber rootstocks (Hevea spp.) in greenhouses covered with transparent low density polyethylene (LDPE), in the field protected by 50% mesh plastic screen as windbreaks and in the unprotected field (control) in Campinas-SP/Brazil, showed no differences in growth in the field with and without protection (Table 10). However, the greenhouse, compared to the control showed increased diameter (60%), height (108%), leaf area (266%) and dry weight (286%), and was the only environment that showed 60% of rootstock with a minimum diameter of 8.0 mm, suitable for grafting (Pezzopane et al., 1995).

With the objective to obtain information on an angelim seedling production system (Andira fraxinifolia Benth) in Sao Cristovao-SE/Brazil, Carvalho Filho et al. (2004) studied two growth environment (50% shading and full sun), substrates and containers and concluded that the seedlings should be maintained in 50% shading and then be transferred to full sun.

Effects of greenhouse and full sun were studied using the parameters of emergence, mortality, stem diameter, plant height, leaf area and dry weight of araticum seedlings (Annona crassiflora Mart.) and it was verified that the stem diameter, plant height and leaf area were greater in the greenhouse and the other variables in full sun (Cavalcante et al., 2008).

The germination of the assacuzeiro (Hura crepitans L.) under 50% shading, greenhouse constructed of polypropylene and environment in full sun was studied by Effgen et al. (2005) in Alegre-ES/Brazil, who concluded that both 50% shade and the environment in full sun provided good conditions for germination.

In canafistula seedlings (Cassia grandis L.), subjected to full sun and 50% shading under the monofilament screen in Sao Cristovao-SE/Brazil, it was observed that plant height, leaf number, stem diameter and dry weight leaf were greater under 50% shading with fast initial growth (Carvalho Filho et al., 2002).

Effects of shading levels of 0%, 30% and 50% in Lavras-MG/Brazil on growth, biomass allocation and total chlorophyll content of young plants of Maclura tinctoria (L.) D. Don ex Steud. (moreira), Senna macranthera (Collad.) Irwin et Barn. (fedegoso), Hymenaea courbaril

L. var. stilbocarpa (Hayne) Lee et Lang. (jatoba) and Acacia mangium Willd. (acacia) revealed that the highest chlorophyll levels were observed in shaded conditions for all species; the chlorophyll a/b ratio in full sun and 50% shading showed no difference between species; in full sun, the fedegoso and moreira species showed greater growth; the diameter of the stem of moreira was smaller in full sun than 50% shading; the dry matter produced by moreira was greater than that of fedegoso, except in the shading level of 30% (Almeida et al., 2005).

Carvalho Filho et al. (2003) evaluated the effect of full sun and 50% shading environments on the production of jatoba seedlings (Hymenaea courbaril L.) in em Sao Cristovao-SE/Brazil, and found that the emergence percentage was higher in full sun, recommending the production of seedlings in this environment. They also observed that for the other features there was interaction between environments, containers and substrates.