Management of corm size and soil water content for gladiolus flower production

Gladiolus grandiflorus Andrews, in the family Iridaceae, is one of the most produced and marketed flowers in the world. In general, however, research results on gladioli production factors are scarce and divergent. The objective of this work was to evaluate the influence of corm size and soil water content on gladiolus flower production. The experimental design, using the early maturity cultivar ‘White Friendship’, was entirely randomized, arranged in a 5 x 2 factorial scheme (five soil water contents: 25; 50; 75; 100; and 125% field capacity, combined with two corm sizes: medium and big), with four replications per treatment. Each replication, composed of one pot, comprised three corms, totaling 40 pots and 120 plants. Both vegetative and flowering characteristics were evaluated. Gladiolus cultivation at 80% soil field capacity presents best results for commercialization, generating longer flower stems with greater diameter and flower number, plus larger flowers. Furthermore, such soil water content promotes the shortest cultivation perio

Germination response of palm seeds on a two-way thermogradient plate

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

Produção sustentável de mudas de amendoim-do-campo para uso na arborização urbana / Sustainable production of peanut seedlings for use in urban afforestation

A necessidade de estudar a utilização dos resíduos de tratamento de esgoto como substrato é de grande importância ambiental para solucionar os problemas de contaminação do solo e de corpos d’água provocados pelo despejo incorreto dos efluentes no ambiente e melhorar a qualidade da formação de mudas para paisagismo e arborização urbana. O estudo deste material foi avaliado com o desenvolvimento de mudas de amendoim-do-campo (Platypodium elegans Vogel) em diferentes concentrações de biossólido e terra de subsolo. O experimento foi instalado no Departamento das Ciências da Produção Agrícola da Faculdade de Ciências Agrárias e Veterinárias – UNESP, Campus de Jaboticabal. O delineamento experimental foi inteiramente casualizado. Foram seis tratamentos, oito repetições e quatro plantas por parcela. Os tratamentos testados foram constituídos por substratos resultantes da mistura de terra de subsolo (TS) e biossólido (BIO) em diferentes proporções: 100% TS (controle); 80% TS + 20% BIO; 60% TS + 40% BIO; 40% TS + 60% BIO; 20% TS + 80% BIO; T6 100% BIO. Para acompanhar o desenvolvimento das mudas de amendoim-do-campo, foram avaliados: altura da parte aérea (cm), comprimento da raiz (cm), diâmetro do coleto (mm), número de folhas, área foliar (cm2), e massa seca da parte aérea, das raízes e total. As características foram avaliadas assim que as raízes das plântulas puderam ser observadas na extremidade inferior dos tubetes. Da análise dos resultados, possibilitou-se concluir que os substratos estudados promoveram diferenças significativas para praticamente todas as características avaliadas das mudas de P. elegans, não existindo significância apenas para comprimento da raiz. As maiores concentrações de biossólido apresentaram os melhores resultados no desenvolvimento das mudas de amendoim-do-campo

Propagação vegetativa e produção de mudas de Bauhinia spp

Espécies de Bauhinia têm sido muito cultivadas em jardins, parques e ruas. Como Bauhinia x blakeana (Bauhinia purpurea x Bauhinia variegata) não produz sementes, é essencial que seja multiplicado vegetativamente. O primeiro objetivo deste trabalho foi verificar a viabilidade da estaquia e da enxertia na propagação desse híbrido. Estacas semilenhosas foram coletadas nas quatro estações do ano e tratadas com diferentes concentrações de AIB. Para a enxertia, mudas de B. variegata e B. variegata var. candida foram usadas como porta-enxerto e os métodos de garfagem tipo inglês simples e borbulhia tipo “T” invertido foram testados. Os resultados desses experimentos indicaram que B. x blakeana pode ser multiplicado por estacas semilenhosas coletadas na primavera, sem o uso do fitorregulador AIB; no verão, dentre as concentrações avaliadas, recomenda-se a aplicação de 3.000 mg L-1 de AIB. Os métodos de enxertia, no entanto, não foram viáveis para a multiplicação desse híbrido. O segundo objetivo deste trabalho foi avaliar a influência de telas de diferentes cores e condições de luminosidade sobre o desenvolvimento inicial de B. variegata e B. variegata var. candida. Plantas de B. variegata e de B. variegata var. candida apresentaram maior eficiência no uso de fotoassimilados quando foram cultivadas sob sol pleno, sendo essa a condição mais adequada para a formação de mudas dessas espéciesBauhinia species have been much cultivated in gardens, parks and streets. As Bauhinia x blakeana (Bauhinia purpurea x Bauhinia variegata) does not produce seeds, it must be vegetatively propagated. The first objective of this work was to verify the viability of the cutting and grafting methods on the propagation of this hybrid. Semi-woody cuttings were collected in the four seasons and submitted to different IBA concentrations. For the grafting experiment, B. variegata and B. variegata var. candida plants were used as rootstocks and the splice-graft and T-budding methods were tested. The results indicated that B. x blakeana can be propagated by semi-woody cuttings collected in spring, without an IBA application; in summer, among the tested concentrations, the application of 3,000 mg L-1 of IBA is recommended. Both the splice graft and T-budding methods were not efficient for the propagation of this hybrid. The second objective of this work was to evaluate the influence of different color shade nets and light conditions on the initial development of B. variegata and B. variegata var. candida seedlings. B. variegata and B. variegata var. candida plants showed more efficiency in the use of their photo-assimilated compounds when they were cultivated under full sun, which is the most suitable condition for the seedling production of these speciesCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Initial growth of Bauhinia variegata trees under different colored shade nets and light conditions

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

A simple and non-destructive model for individual leaf area estimation in citrus

Introduction. Leaf area is often related to plant growth, development, physiology and yield. Many non-destructive models have been proposed for leaf area estimation of several plant genotypes, demonstrating that leaf length, leaf width and leaf area are closely correlated. Thus, the objective of our study was to develop a reliable model for leaf area estimation from linear measurements of leaf dimensions for citrus genotypes. Materials and methods. Leaves of citrus genotypes were harvested, and their dimensions (length, width and area) were measured. Values of leaf area were regressed against length, width, the square of length, the square of width and the product (length x width). The most accurate equations, either linear or second-order polynomial, were regressed again with a new data set; then the most reliable equation was defined. Results and discussion. The first analysis showed that the variables length, width and the square of length gave better results in second-order polynomial equations, while the linear equations were more suitable and accurate when the width and the product (length x width) were used. When these equations were regressed with the new data set, the coefficient of determination (R(2)) and the agreement index 'd' were higher for the one that used the variable product (length x width), while the Mean Absolute Percentage Error was lower. Conclusion. The product of the simple leaf dimensions (length x width) can provide a reliable and simple non-destructive model for leaf area estimation across citrus genotypes