©2023 International Society of Arboriculture Arboriculture & Urban Forestry 49(4): July 2023 163 through only 57% PAR and the aluminized screen of 35% let through 43% PAR. The 30% shading, with 57% of the external PAR, allowed for adequate growth and the obtaining of quality seedlings of Licania tomentosa, since for Hirtella triandra, of the same botanical family (Chrysobalanaceae), the minimum necessary PAR for the development of suitable initial growth is 249.42 µmol m−2 s−1 (Kitajima et al. 2013). The PAR percentage results corroborate those obtained in rubber tree (Hevea brasiliensis) seedlings by Costa et al. (2021), who verified PAR incidence inside an aluminized screenhouse of 46.3% shading and a black screenhouse of 30% shading as 59% of the external PAR. Moreira et al. (2021) observed an internal PAR of 63% of the external PAR in a black screenhouse with 30% shading in the cultivation of biquinho pepper (Capsicum chinense), higher than that observed in the present study. The reflective material did not influence an increase in the quality of oiti seedlings, similar to what was observed by da Silva et al. (2021b) for ach- achairu (Garcinia humilis) seedlings. However, other studies have shown an increase in the quality of seed- lings with the use of reflective material on the cultiva- tion benches, such as baru (Dipteryx alata)(Costa et al. 2020b), jambolan (Syzygium cumini)(Salles et al. 2017), paricá (Schizolobium amazonicum)(Mortate et al. 2019), and rubber tree rootstock seedlings (Hevea brasiliensis)(Costa et al. 2021). diameter at 55 and 70 DAS (H:D2 and H:D3, respec- tively), Dickson quality index (DQI), and the absolute growth rate (AGR) showed significance (Table 2). For the biometric variables influenced by the culti- vation environments, it was observed that the plants produced in the screenhouse with 18% shading had the highest number of variables with the lowest aver- ages. The plants produced in the greenhouse with 42%/50% shading and those produced in the screen- house with 30% shading had the highest means for biometric data (Table 3). For variables with RMSE greater than 7, only the cultivation benches within each cultivation environ- ment were compared. Only for seedling height at 70 DAS (SH3), in the screenhouse with the black screen of 18% shading, plants were larger on the bench with- out reflective material than on the bench with reflec- tive material (Table 4), showing that the reflected radiation did not influence seedling growth. It is observed that the distribution of shoot and root dry matter in oiti seedlings follows a proportion, on average, of 71% for the shoot and 29% for roots, regardless of the cultivation environment and the use or not of reflective material on the bench (Figure 2). DISCUSSION These results show that the shading value does not correspond to the percentage of PAR inside the envi- ronment, since the black screen of 30% shading let Table 2. Analysis of variance for seedling height at 40 (SH1) days after sowing (DAS), number of leaves at 40 (NL1), 55 (NL2), and 70 (NL3) DAS, stem diameter at 55 (SD2) and 70 (SD3) DAS, shoot dry matter (SDM), root dry matter (RDM), total dry matter (TDM), ratio between seedling height and stem diameter at 40 (H:D1), 55 (H:D2), and 70 (H:D3) DAS, Dickson quality index (DQI), absolute growth rate between seedling height at 40 DAS and 55 DAS (AGR12), absolute growth rate between seedling height at 55 and 70 DAS (AGR23), and absolute growth rate between seedling height at 40 and 70 DAS (AGR13) of oiti seed- lings. A = environment; B = cultivation bench; A × B = interaction between environment and cultivation bench; ns = not significant; * = significant at 5%; ** = significant at 1%; CV = coefficient of variation. SH1 NL1 NL2 NL3 SD2 SD3 SDM RDM A * ns ns ns * ns ns ** B ns ns ns ns ns ns ns ns A × B ns ns ns ns ns ns ns ns CV (%) 35.6 53.9 11.2 11.3 6.2 4.4 13.9 16.6 TDM H:D1 H:D2 H:D3 DQI AGR12 AGR23 AGR13 A * ns ** ** * ** ** ** B ns ns ns ns ns ns ns ns A × B ns ns ns ns ns ns ns ns CV (%) 13.1 35.0 7.7 5.9 14.4 26.7 27.9 20.23
July 2023
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