The use of shading has been widely used for production of seedlings, flowers and ornamental plants, aiming to minimize the damage from the excess of luminosity. This research evaluated the effect of different shaded environments [0% (full sun); 35% and 50% of shading and overlapping screens of 35%+50%] on morphophysiological aspects and growth of Heliconia psittacorum cv. Golden Torch and Heliconia bihai cv. Humilis in Bom Jesus county, Piaui state, Brazil, from August, 2012 to July, 2013. The experiment was carried out in a completely randomized design with treatments arranged in a 2 x 4 (Species x Shading) factorial, with six repetitions. Plants of H. bihai cv. Humilis showed higher leaf area compared to H. psittacorum cv. Golden Torch when the corresponding overlapping screens of 35% + 50% was applied, indicating that the two species have different morphological mechanisms for adaptation in shaded environments. Plants grown in full sun (0% of shade) presented lower growth (height and leaf area) and lower chlorophyll content. The 50% of shading providedwas effective to achieve the desired establishment and growth of H. bihai cv. Humilis and H.Psittacorum cv. Golden Torch, grown in pots.

The in vitro seed germination is an effective alternative for quickly obtaining explants with sanitary quality. However, jenipapo seeds present slow and uneven germination. Therefore, internal and external factors to seed which directly interfere in the process, they must be identified, in order to adapt better techniques to obtain seedlings. In this sense, this work aimed to optimize the in vitro germination of Genipa americana L. seeds by evaluating different factors (light quality, GA₃ treatment, pre-soaking in distilled water, growing media and stratification in the dark). It was found that the seed germination of G. americana was indifferent to light, however, the best results were obtained under conditions of continuous darkness; There was no effect of the application of exogenous GA₃; The pre-soaking in distilled water for 48 h contributes to obtaining better germination rates; And the reduction in MS medium salts, and laminating the pretreatment in the dark maximizes the germination potential of seeds.Therefore, the optimal conditions for in vitro germination of G. americana L. seeds requires pre-soaking in distilled water for 48 hours and inoculation into culture media consisting of 1/2 MS + 15 g L^-1 sucrose, with stratification in the dark for 16 days, followed by the transfer to growth chambers with lighting provided by white fluorescent lamps.