José Antonio Saraiva Grossi

Doses e formas de aplicação de nitrogênio no desenvolvimento e produção da cultura do trigo

Objetivou-se avaliar o efeito de doses e formas de aplicacao de nitrogenio sobre o desempenho e producao de duas cultivares de trigo. O experimento, conduzido em Vicosa-MG, de maio a setembro de 2005, foi instalado segundo um esquema fatorial 2x2x5 no delineamento de blocos casualizados, com quatro repeticoes. Os tratamentos avaliados consistiram da combinacao das cultivares de trigo, BRS 210 e Pioneiro, duas formas de aplicacao de adubo nitrogenado (dose total aplicada por ocasiao da semeadura ou 20 kg ha-1 na semeadura e o restante em cobertura no inicio da fase de perfilhamento) e cinco doses de nitrogenio (40, 60, 80, 100 e 120 kg ha-1) tendo como fonte o sulfato de amonio. A cultivar Pioneiro apresentou maior potencial produtivo que a cultivar BRS 210, mas foi menos resistente ao acamamento. O parcelamento da adubacao nitrogenada proporcionou maior acamamento e nao trouxe beneficios a produtividade dos graos. As doses de N promoveram resposta quadratica da produtividade dos graos, com ponto de maxima estimado na dose de 96,8 kg ha-1 e, aumento linear do acamamento de plantas da cultivar Pioneiro.

Silício melhora produção e qualidade do girassol ornamental em vaso

The aim of this research was to evaluate the effect of splitting different Si rates in the production of ornamental pot sunflowers, grown under greenhouse. The Si source was potassium silicate, applied at the substrate. The treatments were arranged in a 5x2 factorial experiment, with five Si rates (0, 150, 300, 450 and 600mg pot-1) and two forms of application (whole or split) in a complete randomized design, with four repetitions. Each repetition is a 5 inch potted F1 hybrid Sunflower Pollenless Sunbright. The inflorescence diameter, plant height, stem diameter, roots dry matter , leaves, inflorescence and the Si content in each plant part were measured. There was no significant interaction of Si rates and its splitting for any evaluated characteristic. The plant height increased with the Si splitting. The flowers and roots dry matter and the flower diameter and shape enhanced with the implementation of Si. The content of Si also increased with the applied Si rates, supporting that the sunflower uptake and accumulates Si in their tissues.

Survival of Botrytis cinerea as mycelium in rose crop debris and as sclerotia in soil

ABSTRACT Botrytis blight caused by Botrytis cinerea is an important disease of rose ( Rosa hybrida ) grown in greenhouses inBrazil. As little is known regarding the disease epidemiology under greenhouse conditions, pathogen survival in crop debrisand as sclerotia was evaluated. Polyethylene bags with petals, leaves, or stem sections artificially infected with B. cinerea were mixed with crop debris in rose beds, in a commercial plastic greenhouse. High percentage of plant parts with sporulationwas detected until 60 days, then sporulation decreased on petals after 120 days, and sharply decreased on stems or leavesafter 90 days. Sporulation on petals continued for 360 days, but was not observed on stems after 150 days or leaves after 240days. Although the fungus survived longer on petals, stems and leaves are also important inoculum sources because highamounts of both are deposited on beds during cultivation. Survival of sclerotia produced on PDA was also quantified. Sclerotiagermination was greater than 75% in the initial 210 days and 50% until 360 days. Sclerotia weight gradually declined but theyremained viable for 360 days. Sclerotia were produced on the buried petals, mainly after 90 days of burial, but not on leavesor stems. Germination of these sclerotia gradually decreased after 120 days, but lasted until 360 days. Higher weight loss andlower viability were observed on sclerotia produced on petals than on sclerotia produced

Rates of nitrogen and growth retardant trinexapac-ethyl on wheat

The objective in this study was to evaluate the effects of nitrogen rates in association with rates of the growth retardant trinexapac-ethyl on wheat. The experiment was conducted in Vicosa, MG and arranged in a 5×4 factorial, randomized block design, with four repetitions. A combination of five nitrogen rates (30, 60, 90, 120 and 150kg ha-1) with four rates of trinexapac-ethyl (0, 62.5, 125 and 187.5g ha-1) were tested. Trinexapac-ethyl promotes reduction of soot dry mass and grain yield at the lowest N rates, but at the highest N rates there is increase in these characteristics. The combination between N and trinexapac-ethyl rates that promotes higher shoot dry mass is 150kg ha-1 and 187g ha-1 but that promotes higher grain yield is 100kg ha-1 and 120g ha-1, respectively.

Yield and shelf life of chrysanthemum in response to the silicon application

O crisântemo de vaso e uma das principais flores produzidas em ambiente protegido. O silicio tem promovido melhorias tanto no aspecto quantitativo quanto no qualitativo quando fornecido a algumas especies ornamentais produzidas nestas condicoes. Assim, o objetivo desse trabalho foi avaliar a resposta a aplicacao de silicio de tres cultivares de crisântemo cultivadas em vaso. O experimento foi conduzido em casa de vegetacao da Universidade Federal de Vicosa. Os tratamentos foram dispostos em esquema fatorial 3x2 (tres cultivares de crisântemo: Coral Charm, White Reagan e Indianapolis e duas doses de silicio aplicadas no substrato: 0 e 800 mg kg-1) com seis repeticoes, em delineamento inteiramente casualizado. Foram avaliados o diâmetro dos botoes e das hastes florais; comprimento das hastes florais; altura da planta; producao de materia seca de raizes, folhas, caule, inflorescencias e parte aerea; numero total de inflorescencias; diâmetro da inflorescencia mais aberta; teor de Si nos tecidos foliares; ciclo e longevidade floral. A cultivar White Reagan produziu o maior numero de inflorescencias (29,17) por vaso e mostrou ser mais precoce (85,83 dias). Nao houve interacao negativa entre Si, Ca e K e nao foi constatado efeito do silicio na producao e na longevidade das inflorescencias de crisântemo. Houve aumento nos teores deste elemento nas folhas com a aplicacao do metasilicato de potassio.

Potential of Spectral Reflectance as Postharvest Classification Tool for Flower Development of Calla Lily (Zantedeschia aethiopica (L.) Spreng.)

El manejo poscosecha inadecuado es uno de los problemas mas serios que la floricultura tiene que enfrentar. Una opcion para reducir las perdidas poscosecha es emplear sistemas automaticos para ordenar y clasificar las flores, los cuales permiten resultados consistentes, reducen gastos y aceleran estas tareas. El objetivo de este trabajo fue demostrar el potencial de la reflectancia espectral para discriminar las diferentes fases de desarrollo poscosecha de flores de cala (Zantedeschia aethiopica [L.] Spreng.), visando el uso de esta tecnologia en sistemas automaticos para la clasificacion de flores. El equipo de medicion fue un espectrometro conectado a un computador portatil y configurado para la adquisicion de datos de reflectancia comprendidos en la region espectral de 400 a 1000 nm. Con base en los resultados, se constato una diferencia entre las curvas de reflectancia espectral, con reducciones graduales en los valores medidos de acuerdo con el aumento de la senescencia. Por tanto, la reflectancia espectral tiene potencial para ser empleada en el desarrollo de sistemas automaticos para clasificacion poscosecha de flores de cala.

Reproductive biology of Cryptostegia Madagascariensis bojer ex decne. (Periplocoideae, Apocynaceae), an ornamental and exotic species of Brazil

Foram analisados a fenologia reprodutiva, a biologia floral, o sistema reprodutivo e os polinizadores de Cryptostegia madagascariensis em individuos cultivados no campus da Universidade Federal de Vicosa, municipio de Vicosa, Zona da Mata de Minas Gerais. Testaram-se, tambem, a viabilidade e o vigor de sementes oriundas de frutos abertos naturalmente e a germinacao de sementes de frutos ainda fechados, mas com o pericarpo verde-amarelado. C. madagascariensis floresce, principalmente, em novembro e dezembro e os frutos (foliculos) podem ser observados durante todo o ano, mas especialmente em janeiro e fevereiro. As flores abrem durante o dia e duram cerca de 24 horas; ha protandria, apresentacao secundaria de polen e compito intrapistilar, que resulta na producao de foliculos gemeos (dois foliculos por flor). E autocompativel, mas a autopolinizacao espontânea nao ocorre devido as caracteristicas morfologicas. Abelhas devem ser os polinizadores, pois foram os principais insetos observados carregando polinario(s) no aparelho bucal. Em todas as flores analisadas verificou-se que pelo menos um polinario e removido por flor. Entretanto, a baixa frutificacao natural (2,7%) indica ser esses insetos eficientes na remocao de polinarios, mas pouco eficazes na deposicao do polen removido. Os foliculos levam cerca de quatro meses para alcancarem o maximo crescimento (media de 6,44 cm de comprimento, 2,45 cm de altura e 3,4 cm de largura) e 210 dias para abrirem; a media de sementes por foliculo e 96,5. As condicoes ideais para avaliar a qualidade de sementes, de foliculos abertos naturalmente, sao temperatura de 30oC constante, sem suplementacao de luz, e contagem de germinacao aos sete dias. Sementes de foliculos ainda fechados apresentaram 93% de germinacao, nessas condicoes.

Cultivo hidropônico de lisianto para flor de corte em sistema de fluxo laminar de nutrientes

The objective of this work was to evaluate yield and commercial traits of lisianthus (Eustoma grandiflorum) flowers growth in nutrient film technique (NFT). The experimental design was in randomized blocks, in factorial scheme (4x3), with three replicates. The treatments were four cultivars (Echo Champagne, Mariachi Pure White, Balboa Yellow and Avila Blue Rim) and three nutrient solutions (Test, modified Steiner and Barbosa). The NFT system is a feasible alternative for the growth of lisianthus in Barbosa and Test solutions. The cultivar Echo Champagne was superior for cycle, length of production, height of flower stem, number of leaves, diameter of the bud flower and fresh and dry weight production, while the cultivar Mariachi Pure White was superior for length of production. The cultivar Avila Blue Rim showed good length of production, number of flowers and fresh and dry matter production, while the cultivar Balboa Yellow had long length of production and bud flower diameter.

Sulfuric acid on breaking dormancy seeds, emergence and post-seminal morphology of Canna edulis L.

he objective of this study was to evaluate the efficiency of time scarification of seeds in sulfuric acid to break the dormancy of seeds, seedling emergence and post-seminal morphology of C. edulis. This way, were determined biometric characteristics of seeds with the help of pachymeter and digital balance. To dormancy breaking, the seeds were immersed in sulfuric acid during 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 hours and sown in sand in a condition greenhouse. After 21 days emergence percentage, emergence speed index (IVE), shoot length and seedling dry weight of plants were recorded. At 0, 2, 4, 8, 12, 16, 20 days after sowing, the seedlings taken digital images and post-seminal morphology was characterized. The fruit of C. edulis contains an average of 19.27 globoses seeds of black coloration measuring about 5.62 mm in diameter, the average weight of 1000 seeds is 128.8 grams. The highest percentage of seedling emergence of 60% and 90% are obtained from seed treated with 0.5 hours in sulfuric acid at 10 and 21 days after sowing, respectively. The seeds have hypogeal germination with development of fasciculate roots with root axes differentiated at 4 days after sowing. The protophyll is observed from the eighth day and the seedlings have intense purple coloration at 16 days after sowing.

Biometry of fruits and seeds, seeds germination and post-seminal development of areca palm

Areca palm is an ornamental palm largely used in landscape which propagate occur by seeds germination. However, the biometry and the endogenous and exogenous factors than can limit propagation of this plant are poorly known, so this work was aimed characterize biometrics of fruits and seeds of areca palm and evaluate the germination of seeds in different substrates. For this, the biometric analyses of length, diameter and weight were recorded; the description of internal and external morphology of frit and seed were also studded. The treatments to improvement of seed germination were intact seeds (T1), intact seeds soaked in 500 mg L -1 GA 3 solution (T2), physically scarified seeds with the aid of sandpaper (T3) and physically scarified seeds after immersion in 500 mg L -1 GA 3 solution (T4). The Seeds were sown in containers containing sand, coir dust or vermiculite. The areca pal fruits and seeds are both, elliptical shape and the weight of fruits and seeds is 1.70g and 1.04g, respectively. There is positive correlation between fruit weight and length and diameter of the fruit and just like the diameter has a positive correlation with the diameter of the seed. The mechanical scarification improve the seed germination. The Coir dust is the most atrophied substrate to seed germination of areca palm. The seed germination of Areca palm is hypogeal and the protrusion of the haustorium was observed at 59 days after sowing and the plantlets is fully grown at 153 after sowing.