The lack of information regarding the water requirement of tree species results in water waste in the seedlings production in nurseries. Water requirement, the growth plant factors and water efficiencies for height and diameter were determined for Schizolobium parahyba (Vell.) Blake, Cytharexylum myrianthum Cham. and Ceiba speciosa Ravenna seedlings, under automated irrigation management and greenhouse conditions, located at 22^o45’53” S and 43^o41’50” W. We used sewage sludge biosolids as substrate in the seedling phase (280 cm^-3 tube), and sandy soil material in the initial pot growth phase (18 dm^-3 pot). In the seedlings phase, four water replacement levels were applied to the substrate, by drip irrigation, corresponding to average replacement ranging from 40 (V1) to 100% (V4) of the species water requirement. Seedlings developed properly and 80 days after emergence, S. parahyba, C. myrianthum and C. speciosa seedlings received, respectively, 2.40, 1.08 and 0.85 L per plant, for V4. After growth phase (230 DAE), the total water volumes were, respectively, 70.0, 50.3 and 52.7 L per plant. Under adequate water supply, there were rapid recovery and growth of the species, even for the seedlings which showed different height and diameter in the tube phase. The growth plant factors values found were below 0.5 for all species indicating low sensitivity to growth, both in height and in diameter, in response to water deficit. Water efficiency indicators point to distinct trends between the two phases, and C. speciosa has higher values of water efficiencies for height (80.7 and 17.0 cm L^-1) and diameter (2.1 and 0.5 mm L^-1) in both phases.

The increase in the demand for seedlings of native tree species makes it important to determine their water and light requirements, which are important factors in their production, in terms of costs and time. Water use and productivity in the growth of seedlings of Dalbergia nigra (Vell.) Allemão ex Benth., Apuleia leiocarpa (Vogel) J.F. Macbr and Hymenaea courbaril L. were determined under four light levels (three shading levels and control), using a randomized block design with four replicates. Height, stem diameter, leaf area and biomass, as well as Dickson quality index (DQI) were evaluated. The seedlings were transplanted into 280-cm3 plugs, filled with substrate composed of pure biosolids, and irrigated by a drip system with automatic management. The highest total volumes applied were 3.1 L per D. nigra seedling (in 37 and 58% shading), 2.5 L per A. leiocarpa seedling (in 37% shading) and 3.8 L per H. courbaril seedling (in full sun). Growth indices, confirmed by the DQI, indicate that shading levels of 37 and 58% for D. nigra, 37% for A. leiocarpa, and full sun for H. courbaril are the most recommended. The highest volumes of irrigation promoted the greatest development of the species, in general for intermediate shading, which provided the highest values of DQI and irrigation water productivity.

Traditionally, irrigation management has not been used in forest nurseries, compromising the efficiency of the system and the quality of seedlings. In this study, we evaluated the quality of seedlings under different irrigation levels and the substrate composed of pure biosolid, and the initial growth of three Atlantic Forest tree species, produced with automated irrigation management. Four irrigation levels (V1 to V4) were applied by dripping on Schizolobium parahyba (Vell.) Blake, Cytharexyllum myrianthum Chamiáo and Ceiba speciosa Ravenna seedlings. After that, the seedlings were planted to evaluate their early growth in pots. The water was applied in response to species requirement and the volume was measured by water flow sensors, connected to an Arduino MEGA board. Height, collar diameter, leaf area, dry mass and chlorophyll content measurements were used to assess plant development on the seedling and early growth stages. Seedlings that received the highest average volume of water (V4) had a higher rate of growth in height and collar diameter for the three species studied. Despite this, the seedlings that received a smaller volume of water (V1) achieve similar size than V4 ones in pots. The plant growth and quality data, in the two phases analyzed, together with the aggregation of the substrate, indicate that the ideal irrigation level is linked to treatments that received the highest volumes of water (V3 and V4) in the seedling production phase. The results obtained indicate that it is possible to save water and produce seedlings of forest species with quality, ensuring their survival in the field.

Water management and meteorological conditions during the cropping phase play an essential role in maintaining the commercial quality of cut flowers. This study evaluates water requirement, sensitivity to water deficit, and commercial quality of gladiolus ‘Amsterdam’ produced with automated irrigation in different growing periods. The experimental design was in randomized blocks with five replicates and consisted of the growing period factors (winter/spring 2018 and autumn/winter 2019) and the irrigation level factors (45% - L1, 60% - L2, 80% - L3, and 100% - L4 of crop water requirement). An automatic irrigation controller was used for irrigation management. At the harvest point, we evaluated the stems for the diameter, number of flowers, spike length, and floral stem length. We also evaluated stomatal conductance, leaf area, and duration of phenological phases on degree-days. The application of 100% crop water requirement using an automatic irrigation controller in the autumn/winter cycle results in better commercial classification. The treatment with 45% of the crop water requirement extended the total duration of the cycle. In conclusion, flower stems of better commercial classification are obtained with 100% of crop water requirement during the autumn/winter cycle.

O Brasil tem hoje uma demanda por 21 milhões de hectares de restauração florestal, e como consequência, uma enorme demanda por mudas nativas. Desta forma, torna-se essencial o uso de técnicas que possam maximizar o uso dos substratos e da água de irrigação, visando a produção de mudas de alta qualidade. Diante deste cenário, o presente estudo teve como objetivo avaliar o crescimento de mudas de Poincianella pluviosa (DC.) L.P.Queiroz produzidas em quatro substratos elaborados a partir de diferentes resíduos (subsolo, lodo de esgoto, serragem compostada e moinha de carvão) e sob duas lâminas de irrigação (0,03 L/h e 0,05 L/h) por dia. O experimento foi conduzido em delineamento inteiramente casualizado com esquema fatorial 4 × 2 (quatro tipos de substratos e duas lâminas d’água), totalizando oito tratamentos. Os substratos foram avaliados quanto às suas características físicas e químicas. Foram mensuradas a altura, o diâmetro de colo e a massa seca da parte aérea e radicular das mudas após 105 dias de emergência. Os substratos S1- lodo de esgoto puro e S4- lodo de esgoto + serragem (1:1) apresentaram melhores características físicas e os substratos S1- lodo de esgoto puro e S3-lodo de esgoto + moinha de carvão (1:1) exibiram melhor composição nutricional. Para crescimento em altura não foram observadas diferenças entre os substratos e lâminas de irrigação testados. Os substratos constituídos por 50% de lodo e 50% de moinha de carvão ou serragem e com a maior lâmina de irrigação resultaram em mudas com maior diâmetro, biomassa e qualidade, sendo os mais indicados à produção de P. pluviosa.

The lack of information regarding the water requirement of tree species promotes water waste in the seedlings production in nurseries. Water requirement, the growth plant factors and water efficiencies for height and diameter were determined for Schizolobium parahyba (Vell.) Blake, Cytharexylum myrianthum Cham. and Ceiba speciosa Ravenna seedlings, under greenhouse conditions and automated irrigation management. We used sewage sludge biosolids as substrate in the seedling phase (280 cm ^-3 tube), and sandy soil material in the initial pot growth phase (18 dm ^-3 pot). In the seedlings phase, four water replacement levels were applied to the substrate, by drip irrigation, meaning average replacement ranging from 40 (V1) to 100% (V4) of species water requirement. Seedlings developed properly and 80 days after emergency, S. parahyba, C. myrianthum and C. speciosa seedlings received, respectively, 2.40, 1.08 and 0.85 L per plant, for V4. After growth phase (230 DAE), the total water volumes were, respectively, 70.0, 50.3 and 52.7 L per plant. Under adequate water supply, there were rapid recovery and growth of the species, even for the seedlings which showed different height and diameter in the tube phase. The growth plant factors values found were below 0.5 for all species indicating low sensibility to growth, both in height and in diameter, in response to water deficit. Water efficiency indicators point to distinct trends between the two phases, and C. speciosa present higher values of water efficiencies for height (80.7 and 17.0 cm L ^-1 ) and diameter (2.1 and 0.5 mm L ^-1 ) in both phases.