EFFECTS OF SUBSTRATE AND WATER AVAILABILITY ON THE INITIAL GROWTH OF Alibertia edulis RICH.

Alibertia edulis Rich. is a native species of the Brazilian Cerrado and can be used for reforestation of degraded areas. In addition, it produces edible fruits. The objective of this study was to evaluate the effect of substrates and water levels on the emergence, initial growth, and quality of seedling of A. edulis. The substrates tested were: latosol (L), latosol + sand (L + S = 1:1), latosol + sand + chicken manure (L + S1 + CM = 1:1:0,5), latosol + sand + chicken manure (L + S2 + CM = 1:2:0,5), and latosol + commercial substrate (L + C = 1:1); and the water retention capacities (WRC) tested were: 25, 50, 75, and 100%. The experiment was carried through in a completely randomized design and subdivided into a plot scheme, in which the plots represented water availability and the subplots represented the substrates. Latosol + commercial substrate at 100% of WRC provided the best conditions for emergence, initial growth and formation of seedlings of A. edulis. Sowing in the substrate Dystroferric Red Latosol isolated at 25% of WRC should not be used for the formation of seedlings of this species.Alibertia edulis Rich. is a native species of the Brazilian Cerrado and can be used for reforestation of degraded areas. In addition, it produces edible fruits. The objective of this study was to evaluate the effect of substrates and water levels on the emergence, initial growth, and quality of seedling of A. edulis. The substrates tested were: latosol (L), latosol + sand (L + S = 1:1), latosol + sand + chicken manure (L + S1 + CM = 1:1:0,5), latosol + sand + chicken manure (L + S2 + CM = 1:2:0,5), and latosol + commercial substrate (L + C = 1:1); and the water retention capacities (WRC) tested were: 25, 50, 75, and 100%. The experiment was carried through in a completely randomized design and subdivided into a plot scheme, in which the plots represented water availability and the subplots represented the substrates. Latosol + commercial substrate at 100% of WRC provided the best conditions for emergence, initial growth and formation of seedlings of A. edulis. Sowing in the substrate Dystroferric Red Latosol isolated at 25% of WRC should not be used for the formation of seedlings of this specie

Temperatures and qualities of light in Niger (Guizotia abyssinica (L.f.) Cass.) seeds germination in Mato Grosso do Sul, Brazil

For each vegetable species, there is a specific environment conditions to occur the seed germination process. However, there is a little information regarding the necessary conditions for Niger (Guizotia abyssinica (L.f.) Cass.) seeds germination. The aim of this research was to evaluate the influence of different temperatures and types of light on Niger (Guizotia abyssinica (L.f.) Cass.) seeds germination. Seeds were sown on two sheets of “germitest” paper inside plastic box type “gerbox” and placed on B.O.D. Treatments were constituted of two constant temperatures (15 ºC and 25 ºC, respectively) and an alternating temperature (20-30 ºC) under 10 hours for the lowest temperature and 14 hours for the highest temperature and they were associated to the wavelengths as follows: blue (440 nm), green (560 nm), red (660 nm), extreme red (730 nm), white light and dark. The experiment was conducted in a completely randomized design with four replicates of 50 seeds. Effects of different temperatures and qualities of light were evaluated by seeds germination and vigor. Higher germination of Niger seeds is observed in temperatures of 25 and 20-30 ºC and they can be considered as non-photoblastic.For each vegetable species, there is a specific environment conditions to occur the seed germination process. However, there is a little information regarding the necessary conditions for Niger (Guizotia abyssinica (L.f.) Cass.) seeds germination. The aim of this research was to evaluate the influence of different temperatures and types of light on Niger (Guizotia abyssinica (L.f.) Cass.) seeds germination. Seeds were sown on two sheets of “germitest” paper inside plastic box type “gerbox” and placed on B.O.D. Treatments were constituted of two constant temperatures (15 ºC and 25 ºC, respectively) and an alternating temperature (20-30 ºC) under 10 hours for the lowest temperature and 14 hours for the highest temperature and they were associated to the wavelengths as follows: blue (440 nm), green (560 nm), red (660 nm), extreme red (730 nm), white light and dark. The experiment was conducted in a completely randomized design with four replicates of 50 seeds. Effects of different temperatures and qualities of light were evaluated by seeds germination and vigor. Higher germination of Niger seeds is observed in temperatures of 25 and 20-30 ºC and they can be considered as non-photoblastic

SUBSTRATOS E NÍVEIS DE LUMINOSIDADE NO CRESCIMENTO INICIAL DE MUDAS DE Tocoyena formosa (Cham. & Schltdl.) K. Schum. (RUBIACEAE)

The aim of this study was to determine the best substrate type and light conditions for the cultivation of seedlings of Tocoyena formosa (Cham. & Schltdl.) K. Schum. Seeds were planted in Styrofoam trays under 70% shading. Three months after emergence, the seedlings were selected and transplanted in 4-L pots, in two types of substrates: 50% dystroferric Red Latosol + 50% sand (TA) and 50% dystroferric Red Latosol + 25% sand + 25% semi-decomposed chicken manure (TACF). After transplanting, the seedlings were placed under three conditions of shading (30, 50 and 70% shade) and full sun (0% shade). After acclimation, the physiologic quality of the seedlings was determined monthly, by analysis of growth and Dickson quality index, for 270 days. The experiment was carried out using a randomized block design in a 2 x 4 x 4 factorial scheme (substrate x shading x age of seedling), with three repetitions of three seedlings. There was greater growth and quality of the seedlings in the substrate soil + sand + chicken manure and under conditions of 30% shade and full sun. It is concluded that for the production of seedlings of Tocoyena formosa, the best conditions are 30% shade and full sun for light and TACF for substrate.Objetivou-se determinar o tipo de substrato e as melhores condições de luminosidade para o cultivo de mudas de Tocoyena formosa (Cham. & Schltdl.) K. Schum. A semeadura ocorreu em bandejas de isopor sob sombrite de 70% e três meses após a emergência, as plântulas foram selecionadas e em seguida transplantadas em vasos de 4L, em dois tipos de substratos: 50% de solo Latossolo Vermelho Distroférrico + 50% de areia (TA) e 50% de solo de Latossolo Vermelho Distroférrico + 25% de areia + 25% de cama de frango semidecomposta (TACF). Após o transplante, as mudas foram levadas para três condições de sombreamento (30%, 50% e 70% de sombra) e a pleno sol (0%). Após a aclimatação, a qualidade fisiológica das mudas foi determinada mensalmente, através da análise de crescimento e do índice de qualidade de Dickson, durante 270 dias. O experimento foi realizado em DIC em esquema fatorial 2 x 4 x 4 (substratos x sombreamento x idade da muda), com três repetições de três mudas. Foi observado maior crescimento e qualidade das mudas em substrato terra + areia + cama de frango e nas condições de 30% de sombra e pleno sol. Conclui-se que para produção de mudas de Tocoyena formosa a melhor condição de luminosidade é 30% de sombra e em pleno solem substrato TACF

SUBSTRATES AND WATER AVAILABILITY ON THE EMERGENCE AND INITIAL GROWTH OF Alibertia sessilis Schum. SEEDLINGS

The cultivation of native species in the Cerrado has encountered various problems, for instance, the slow growth and the lack of knowledge about the cultivation practices. In order to better use the available water resources and to produce quality seedlings, this study aimed to evaluate different substrates and water levels on the emergence and initial growth of Alibertia sessilis Schum. seedlings. The effects of the following substrates were evaluated: dystroferric Red Latosol (Oxisol), Oxisol +sand (1:1 v/v), Oxisol + sand + semi-decomposed poultry litter (1:1:0.5 v/v), Oxisol + sand 2 + semi-decomposed poultry litter (1:2:0.5 v/v) and Oxisol + commercial-substrate-CS (1:1 v/v) associated with the levels of irrigation of 25, 50, 75 and 100% of the water holding capacity in the substrate (WHC). The best results for emergence percentage, initial growth and quality of seedlings were observed in the substrates Oxisol + sand 2 + poultry litter (1:2:0,5) at 100% of WHC. There was no emergence at 25% of WHC.           Keywords: Rubiaceae, marmelinho, fruit of the Cerrado. ResumoSubstratos e disponibilidade hídrica na emergência e crescimento inicial de mudas de Alibertia sessilis Schum. O cultivo de espécies nativas no Cerrado tem esbarrado em vários problemas, entre eles, o crescimento lento e a carência de conhecimentos sobre as práticas culturais. A fim de melhor utilizar os recursos hídricos disponíveis e produzir mudas de qualidade, objetivou-se no presente trabalho avaliar diferentes substratos e níveis de água na emergência e no crescimento inicial das mudas Alibertia sessilis Schum. Foram avaliados os efeitos dos substratos Latossolo Vermelho distroférrico (LVd), LVd +areia (1:1 v/v), LVd + areia + cama de frango semidecomposta (1:1:0,5 v/v), LVd + areia 2 + cama de frango semidecomposta (1:2:0,5 v/v) e LVd + substrato comercial -SC (1:1 v/v) associados aos níveis de irrigação de 25, 50, 75 e 100% da capacidade de retenção de água no substrato (CRA). Os melhores resultados para porcentagem de emergência, crescimento inicial e qualidade das mudas foram observados nos substratos LVd + areia 2 + cama de frango (1:2:0,5) a 100% da CRA.  Não houve emergência a 25% da CRA.          Palavras-chave: Rubiaceae, marmelinho, frutífera do Cerrado.The cultivation of native species in the Cerrado has encountered various problems, for instance, the slow growth and the lack of knowledge about the cultivation practices. In order to better use the available water resources and to produce quality seedlings, this study aimed to evaluate different substrates and water levels on the emergence and initial growth of Alibertia sessilis Schum. seedlings. The effects of the following substrates were evaluated: dystroferric Red Latosol (Oxisol), Oxisol +sand (1:1 v/v), Oxisol + sand + semi-decomposed poultry litter (1:1:0.5 v/v), Oxisol + sand 2 + semi-decomposed poultry litter (1:2:0.5 v/v) and Oxisol + commercial-substrate-CS (1:1 v/v) associated with the levels of irrigation of 25, 50, 75 and 100% of the water holding capacity in the substrate (WHC). The best results for emergence percentage, initial growth and quality of seedlings were observed in the substrates Oxisol + sand 2 + poultry litter (1:2:0,5) at 100% of WHC. There was no emergence at 25% of WHC

Sombreamento na emergência de plântulas e no crescimento inicial de Dipteryx alata Vog.

http://dx.doi.org/10.5902/198050986611This work was carried out in order to evaluate the potential of germination of the seeds and the seedlings growth of  baru (Dipteryx alata) in different levels of shading. To evaluate the emergency, the sowing was realized in trays of cells contends Plantmax® substratum + land + sand + chicken manure in proportion of (1: 1: 1: 0,5) and kept  in the full sun, 50% and 70% of shading. The experiment was realized in design entirely randomized with three levels of shading in four repetitions of 25 seeds. It was evaluated the percentage and the velocity of the emergency index. To evaluate the initial growth, the seedlings were transplanted and, three repetitions of 15 changes totalizing 45 seedlings were kept in its respective shading.  The experiment was realized in a complete randomized design in factorial 3 (shading levels) x 5 (times of evaluation for height, diameter of collect, total chlorophyll, transpiration, stomatal conductance and photosynthetic rate) and 2 (times of evaluation for leaf area, length of root, fresh and dry mass). The shading levels did not influence the percentage and the velocity index of seedling emergency.http://dx.doi.org/10.5902/198050986611Esse trabalho foi desenvolvido com o objetivo de avaliar o potencial de emergência das plântulas e o crescimento das mudas do baru (Dipteryx alata Vog.) em diferentes níveis de sombreamento. Para avaliar a emergência, a semeadura foi realizada em bandejas de células contendo substrato Plantmax® + terra + areia + cama de frango na proporção de 1:1:1:0,5 e mantidas a pleno sol, 50 % e 70 % de sombreamento. O experimento foi realizado em delineamento inteiramente casualizado com três níveis de sombreamento em quatro repetições de 25 sementes. Foram avaliados a porcentagem e o índice de velocidade de emergência. Para avaliar o crescimento inicial, as plântulas foram transplantadas e três repetições de 15 mudas, totalizando 45 mudas, foram mantidas em seus respectivos sombreamentos. O experimento foi realizado em delineamento inteiramente casualizado em esquema fatorial 3 (níveis de sombreamento) x 5 (épocas de avaliação para a altura, diâmetro do coleto, clorofila total, transpiração, condutância estomática e taxa fotossintética) e 2 (épocas de avaliação para área foliar, comprimento de raiz, massas fresca e seca). Os níveis de sombreamento não influenciaram na porcentagem nem no índice de velocidade de emergência das plântulas (71,3 % e 1,08, respectivamente). Os maiores valores de altura (16 cm), área foliar (220,2 cm2), comprimento de raiz (14,9 cm), massa fresca e seca (9,71 g e 3,21 g) das mudas foram observados sob sombreamento, não variando entre eles. As mudas apresentaram a menor taxa fotossintética a 70 % de sombreamento (6,8 μmol m-2s-1). Os níveis de sombreamento avaliados não influenciaram na emergência das plântulas, entretanto, as mudas apresentaram melhor crescimento quando mantidas até os 125 dias de idade sob 50 % de sombreamento

Substrate water availability and seed water content on niger germination

Niger is an oleaginous species whose cultivation has been spreading, but there is not much information on the adverse conditions during its seedling establishment. This study aimed at evaluating the effects of substrate water availability and seed water content on niger germination. Seeds were moistened using the humid atmosphere method for 0; 24; 48; and 72 hours, obtaining the water contents of 7.0 %, 12.8 %, 16.8 % and 32.2 %. Then, they were sown in substrate moistened with PEG 6000 solutions with different osmotic potentials: 0.0 MPa (control), -0.1 MPa, -0.2 MPa, -0.3 MPa and -0.4 MPa. A completely randomized design, in a 4 x 5 factorial scheme (water content x osmotic potential), with four replications of 50 seeds, was used. First count and germination percentage, germination speed index and mean time, shoot and root length and seedlings dry weight were evaluated. The reduction in the substrate osmotic potential decreases the niger seed germination and seedling growth, regardless of water content, but with a higher evidence in seed water contents below 32.2 % and 12.8 %, respectively

INFLUENCE OF EXOGENOUS APPLICATION OF ABSCISIC ACID IN GAS EXCHANGES OF Hymenaea courbaril L. (FABACEAE) SEEDLINGS SUBJECTED TO WATER DEFICIT

This study was carried out in the greenhouse of the Federal University of Grande Dourados (UFGD), in the municipality of Dourados, state of Mato Grosso do Sul, Brazil, from April to May of 2015. The aim of this study was to assess the effect of different concentrations of abscisic acid (ABA) on the responses under water stress and recovery of Hymenaea courbaril L. seedlings after reirrigation. The following six treatments were assessed: 1) Irrigation with no ABA; 2) Irrigation + 10 µM ABA; 3) Irrigation + 100 µM ABA; 4) No irrigation nor ABA; 5) No irrigation + 10 µM ABA; and 6) No irrigation + 100 µM ABA. No irrigation treatment consisted on water suspension until the photosynthetic rate was close to zero. The plants were then irrigated daily to maintain 70% of the water holding capacity of the soil for a 12-days recovery period. ABA doses applied exogenously during the no irrigation period neither prevented the reduction of photosynthetic activity nor optimized the recovery of gas exchanges and carboxylation efficiency of Rubisco after water and seedling quality restoration. The concentration of 100 µM ABA promoted the degradation of chlorophylls independently of irrigation, which shows that high concentrations of ABA may cause a residual effect on this species. The seedlings exhibited normal metabolic recovery after about 12 days of reirrigation of the soil due to the characteristics of the species and not the tested treatments

PHOSPHATE FERTILIZATION AND SHADING ON THE INITIAL GROWTH AND PHOTOCHEMICAL EFFICIENCY OF Campomanesia xanthocarpa O. BERG.

Campomanesia xanthocarpa O. Berg. (“Gabirobeira”, Myrtaceae) is a versatile fruit tree species native in Cerrado. Studies of mineral fertilization and luminous conditions with the species are incipient. Thus, the aim was to evaluate the initial growth and photochemical aspects in C. xanthocarpa cultivated under phosphate fertilization and shading levels. The experiment was carried out in plastic pots and the factors under study consisted of five doses of phosphorus: 0, 50, 100, 150 and 200 mg kg soil-1, and two shadings levels: 0% (full sun) and 50%. The treatments were arranged in a 5 x 2 factorial scheme, in a randomized block design, with four replications. The greatest growth characteristics occurred at 240 days after transplantation. The highest chlorophyll index was seen in shaded leaves. The highest values of variable and maximum chlorophyll-a fluorescence were with 10.8 and 11.6 mg P kg-1 in shaded environments, and with 120.0 and 81.81 mg P kg-1, under full sun. The highest photochemical efficiency in photosystem II (Fv/Fm) was under full sun with 33.33 mg P kg-1. The analysis of main components explained 78.82% of the remaining variability. The shaded C. xanthocarpa plants showed higher photochemical yields with the addition of low phosphorus doses. Phosphate fertilization contributed to the mitigation of photochemical damage in young plants of C. xanthocarpa cultivated under full sun