ABSTRACT Palm trees are propagated almost exclusively by seeds and each species germinates under a certain temperature range. In this sense, the two-way thermogradient plate may be used to determine temperature limits for germination and seed response to temperature. The objective was to define the alternating temperature regime promoting higher and faster seed germination of Carpentaria acuminata and Phoenix canariensis palms using a two-way thermogradient plate. This equipment allowed 64 combinations of alternating and constant temperatures, ranging from 6.97 to 36.42 ºC for C. acuminata, and 7.96 to 35.94 ºC for P. canariensis. Seeds were sown in Petri dishes (25 x 9 cm) containing 1% water agar. Linear regressions were estimated to determine cardinal temperatures. After 50 days, non-germinated seeds were transferred from the two-way thermogradient plate to a germination chamber at 30 °C. The temperature regime promoting highest seed germination percentage of C. acuminata was 30.45/33.00 °C (day/night), with minimum, optimum, and maximum temperatures of 9.13, 28.53, and 36.33 °C, respectively. For seed germination of P. canariensis, the most appropriate temperature regime was 29.77/17.93 °C (day/night), with minimum, optimum, and maximum temperatures of 9.53, 28.03, and 35.43 °C, respectively.

ABSTRACT The intercropping of corn with forage grasses increases soil cover and may improve soil structural quality. The objective of the study was to evaluate the soil structural properties and the development of second-crop corn intercropping with forage grasses under no-tillage system. The experiment was carried out in an area of Sítio Santo Antônio, located in the municipality of Borrazópolis, Paraná state, Brazil, on a Red Latosol with a very clayey texture. The experiment consisted of five treatments: corn + Urochloa brizantha cv. Marandu (T1), corn + Urochloa brizantha cv. Piatã (T2), corn + Urochloa brizantha cv. Xaraés (T3), corn + Urochloa ruziziensis (T4), and non-intercropping corn (T5). In the corn crop, the following characteristics were evaluated: plant height, first ear in insertion height, stem diameter, corn yield, dry mass of corn straw mulch, dry mass of grasses shoots and dry mass of grasses root. Dry mass of the aerial part and roots of the grasses were evaluated. In the 0–0.10 and 0.10–0.20-m soil depth, soil physical properties were also determined: tensile strength and friability, stability of aggregates, bulk density and total porosity, and degree of compactness. The treatments of corn in intercropping with grasses showed positive results regarding the stability of aggregates, reduction of bulk density and increase of total porosity in the 0–0.10-m soil depth. The intercropping of corn + U. ruziziensis showed the lowest values of degree of compactness and higher production of dry mass of the aerial part.

Resumo A grama Zoysia japonica apresenta importância comercial para o Brasil devido à utilização em campos de golfe e estádios de futebol. Em produção comercial, a principal preocupação é a desuniformidade na germinação, bem como a época ideal da colheita das sementes. Assim, o objetivo foi avaliar o efeito da temperatura e do nitrato de potássio na superação da dormência, e do substrato e da época de colheita na germinação de sementes de grama-esmeralda (Zoysia japonica Steud). Foram realizados três experimentos: 1) tratamentos de temperatura e nitrato de potássio, sendo seis condições de temperatura (constantes a 20 ˚C, 25 ˚C, 30 ˚C e 35 ˚C, e alternadas a 20-30 ˚C e 20-35 ˚C), na ausência ou presença de nitrato de potássio; 2) tratamentos de temperatura e substrato, sendo duas condições de temperatura (alternadas a 20-30 ˚C e 20-35 ˚C) e três tipos de substratos (sobre papel, entre papel e sobre areia); e 3) tratamentos de época de colheita, cujas sementes foram obtidas por meio de colheita manual durante 11 períodos. As sementes germinaram mais rapidamente nos substratos sobre areia e sobre papel, na temperatura alternada a 20-35 ºC. O melhor período para a colheita das sementes foi de 18 a 19 dias após o surgimento das espigas no campo de produção.

Abstract Zoysia japonica grass has commercial importance to Brazil due to its use in golf courses and football stadiums. The main concern about its commercial cultivation is the unevenness on seed germination as well as the ideal seed harvesting time. Therefore, the objective was to measure the effect of temperature and potassium nitrate on dormancy overcoming, and of substrate and harvesting time on germination of zoysia grass seeds (Zoysia japonica Steud). There were three experiments: 1) temperature and potassium nitrate treatments, with six temperature conditions (constants at 20 ˚C, 25 ˚C, 30 ˚C, and 35 ˚C, and alternating at 20-30 ˚C and 20-35 ˚C), under absence or presence of potassium nitrate; 2) temperature and substrate treatments, with two temperature conditions (alternating at 20-30 ˚C and 20-35 ˚C) and three types of substrates (on paper, between paper, and on sand); and 3) harvesting time treatments, which seeds were obtained by manual harvesting comprising 11 harvesting periods. Seeds germinated more rapidly on the sand and paper, at the alternating temperature of 20-35 °C. The best period for seed harvesting was from 18 to 19 days after ear emergence in the production field.

Resumo A azaleia (Rhododendron simsii Planch.) é uma planta ornamental originária da China, propagada comercialmente por estacas e muito cultivada no Brasil devido à beleza de suas flores. No entanto, apresenta dificuldades no enraizamento, o que pode provocar uma redução na produção comercial dessas mudas. Dessa forma, é necessária a aplicação de fitorreguladores para alcançar o sucesso do enraizamento, bem como a utilização de nutrientes que estejam envolvidos nos processos bioquímicos e fisiológicos das plantas. O objetivo do trabalho foi avaliar a influência do ácido indolbutírico (AIB) e do boro no enraizamento de estacas herbáceas das cultivares de azaleia Otto e Terra Nova. Os experimentos foram realizados em uma propriedade particular especializada na produção de azaleias em vasos, localizada em Holambra/SP, e as avaliações foram realizadas no Laboratório de Sementes e Plantas Hortícolas do Departamento de Produção Vegetal, da Faculdade de Ciências Agrárias e Veterinárias da Universidade Estadual Paulista (FCAV/UNESP), em Jaboticabal/SP. O delineamento experimental, para cada experimento com cada cultivar, foi o inteiramente casualizado. Os tratamentos foram arranjados em esquema fatorial 4x4 (concentrações de AIB x concentrações de boro) com quatro repetições e 10 estacas por repetição. A avaliação foi realizada seis semanas após o estaqueamento. Concluiu-se que a auxina e o boro não influenciaram na porcentagem de enraizamento das estacas para ambos as cultivares. No entanto, a cultivar Otto apresentou um sistema radicular de melhor qualidade quando as estacas foram tratadas com 2.000 mg L−1 de AIB na ausência de boro.

Abstract Azalea (Rhododendron simsii Planch.) is an ornamental plant native to China, propagated commercially by cuttings and cultivated in Brazil due to the beauty of its flowers. However, it presents rooting difficulties, which can lead to a reduction in the commercial production of these seedlings. Thus, the application of plant regulators is necessary to achieve rooting success as well as of nutrients that are involved in biochemical and physiological plant processes. This work aimed to evaluate the rooting performance of Otto and Terra Nova azalea herbaceous cuttings treated with indolebutyric acid (IBA) and boron. The experiments were conducted at a private property specialized in the production of potted azalea, located in Holambra County, São Paulo State, Brazil, and the evaluations were carried out at the Plant Seed Laboratory of the Crop Production Department, São Paulo State University (Unesp), School of Agricultural and Veterinarian Sciences, Jaboticabal. The experimental design for each experiment with each cultivar was completely randomized. The treatments were arranged in a 4x4 factorial scheme (IBA concentrations x boron concentrations) with four replications and 10 cuttings per replication. The evaluation was performed six weeks after experiment beginning. Auxin and boron did not influence rooting percentage of cuttings of both cultivars. However, Otto cultivar presented a better-quality root system when cuttings were treated with 2,000 mg L−1 IBA in the absence of boron.

Abstract The objective was to undertake the visual evaluation of soil structure in maize and forage grasses intercropping under no-tillage. The experiment was carried out in a rural property located in North Paraná State, Brazil, where there were five parallel areas with the following treatments: maize + Urochloa brizantha cv. Marandu (T1), maize + Urochloa brizantha cv. Piatã (T2), maize + Urochloa brizantha cv. Xaraés (T3), maize + Urochloa ruziziensis (T4), and non-intercropping maize (T5). Seeds of forage grasses were sown in April 5th, 2018 and sampling was carried out in December, 30th, 2018. Samples of 0.10 m width, 0.20 m length, and 0.25 m thickness were collected from five random locations of each experimental area and, for the visual evaluation of soil structural quality, a soil evaluation (VESS) chart was used so that visual scores were attributed to each sample. Treatments 1 and 5 received the highest scores, while treatment 3 had the lowest score and showed good structural quality and great root presence. At the superficial layer, treatment 2 had the lowest score (0.8) among treatments. For the subsuperficial layer, the scores obtained were higher than those found for the superficial layer: T3 had the lowest mean (1.5) and was significantly similar to T4 that presented a mean score of 1.7. Except for T1, which showed a similar score to non-intercropping maize (T5), the forage grasses had better visual scores. The visual evaluation of soil structure indicated that maize and forage grasses intercropping improves soil structural quality.

RESUMO As palmeiras são amplamente utilizadas como plantas ornamentais, além da importância para a sustentabilidade e para a indústria. A propagação comercial destas plantas é realizada por meio de sementes. Devido à importância da espécie e à necessidade de elucidar alguns aspectos relacionados à germinação das sementes, este trabalho teve como objetivo verificar o efeito de temperatura, regimes de luz e tolerância a dessecação na germinação de sementes da palmeira Mauritia flexuosa L.f. Foram realizados dois experimentos e em ambos o delineamento experimental foi o inteiramente casualizado. No primeiro, estudou-se o efeito da temperatura e da luz e os tratamentos foram dispostos em esquema fatorial 6 x 2 (seis temperaturas: 20 ºC, 25 ºC, 30 ºC, 35 ºC, 20-30 ºC e 25-35 ºC combinadas com presença e ausência de luz); foram quatro repetições de 25 sementes por parcela. No segundo, estudou-se a tolerância a dessecação e os tratamentos foram cinco teores de água nas sementes (51%, 48%, 45%, 30% e 26%) aferidos a cada três dias de um lote mantido em condições ambiente; foram quatro repetições de 25 sementes por parcela. Avaliou-se a porcentagem de germinação e Índice de Velocidade de Germinação. Os dados foram submetidos à análise de variância; as médias de temperatura e de luz foram comparadas pelo teste de Tukey (P < 0.05) e para dessecação realizou-se a análise de regressão polinomial. A temperatura de 20-30 ºC foi a que apresentou maiores médias de porcentagem e de velocidade de germinação independentemente da presença ou ausência de luz. As sementes de M. flexuosa se mostraram sensíveis à dessecação.

ABSTRACT Palm trees are widely used as ornamental plants, besides its sustainability and industry aspects. These plants are commercially propagated via seeds. Due to its importance and the need for seed germination information, this study aimed to verify the effect of temperature, light regimes, and desiccation tolerance on germination of Mauritia flexuosa L.f. For that, two completely randomized experiments were carried out. The first consisted of treatments arranged in a 6 x 2 factorial scheme, testing six temperatures (20, 25, 30, 35, 20-30, and 25-35 ºC) and light presence and absence. The second comprised five seed water contents (51, 48, 45, 30, and 26%) for desiccation tolerance evaluations. Water content measurements were made every three days, from a sample lot maintained at room temperature. In both trials, each treatment was composed of four replicates with 25 seeds per plot. Germination rate (GR) and germination speed index (GSI) were calculated, and the data were analyzed by analysis of variance (ANOVA). Temperature and light means were compared by the Tukey’s test (p < 0.05), and the desiccation ones by a polynomial regression. The highest GR was observed at 20-30 ºC, regardless of light presence. Moreover, M. flexuosa seeds were sensitive to desiccation.

Bauhinia variegata e B. variegata var. candida, popularmente conhecidas como pata-de-vaca, são árvores de porte baixo muito usadas na arborização urbana e no paisagismo. Plantas adultas crescem sob sol pleno; no Brasil, no entanto, mudas são geralmente cultivadas em viveiros comerciais sob meia-sombra. O objetivo deste trabalho foi avaliar a influência de diferentes telas coloridas e condições de luminosidade no crescimento inicial de mudas de B. variegata e B. variegata var. candida. A influência de seis condições de luminosidade (tela vermelha com 50% de sombreamento, tela azul com 50% de sombreamento, tela preta com 70% de sombreamento, tela preta com 50% de sombreamento, tela preta com 30% de sombreamento e a sol pleno) no crescimento inicial das mudas foi avaliada ao longo de 160 dias, e relações de crescimento foram calculadas. As mudas foram mais eficientes no uso dos fotoassimilados quando cultivadas a sol pleno. Essa condição é a mais apropriada para a produção de mudas de B. variegata e B. variegata var. candida, contrariando o que vem sendo feito na prática.

Bauhinia variegata and B. variegata var. candida, commonly known as orchid trees, are small sized trees widely used for urban forestry and landscaping. Adult plants grow under full sun; in Brazil, however, seedlings are generally cultivated in commercial nurseries under natural half-shading. The objective of this study was to evaluate the influence of different colored shade nets and light conditions on the initial growth of B. variegata and B. variegata var. candida. The influence of six light conditions (red net with 50% shading; blue net with 50% shading; black net with 70% shading; black net with 50% shading; black net with 30% shading; and full sun) on the initial growth of B. variegata and B. variegata var. candida were evaluated along 160 days, and growth relationships were calculated. Seedlings showed more efficiency on the use of photoassimilated compounds when grown under full sun. Such condition is the most appropriate for seedling production of B. variegata and B. variegata var. candida, contradicting what has been performed in practice.