Antonio Augusto do Lago

Efeito da vinhaça no desenvolvimento inicial de girassol, mamona e amendoim em casa de vegetação

O trabalho teve como objetivo verificar o efeito da aplicacao ao solo da vinhaca, residuo da industria canavieira, na emergencia de plântulas e no desenvolvimento inicial de girassol, mamona e amendoim - culturas com potencial de utilizacao na sucessao com a cana-de-acucar. O experimento foi desenvolvido em vasos com terra, dispostos em blocos ao acaso, sendo cada especie avaliada individualmente, em esquema fatorial 2 x 3, em quatro repeticoes. Os tratamentos originaram-se de combinacoes da aplicacao ou nao da vinhaca (150 m3 ha-1) sobre tres cultivares de girassol (IAC Iarama, Catissol e Helio 358), de mamona (Guarani, Iris e IAC 2028) e de amendoim (IAC Caiapo, Runner IAC 886 e Tatu). Determinaram-se a velocidade de emergencia de plântulas, a primeira contagem e a porcentagem final de emergencia, alem do comprimento e biomassa seca da parte aerea de plantas, em avaliacao realizada aos 30 dias apos a semeadura. Os resultados atestam que, sob condicoes de vegetacao, a aplicacao de 150 m3 ha-1 de vinhaca ao solo e prejudicial a emergencia e ao desenvolvimento inicial de plantas de amendoim e em menor grau, de girassol, independentemente da cultivar estudada; para mamona, a interferencia ocorre de forma positiva, principalmente sobre as variaveis relacionadas ao vigor inicial das plântulas, com melhor desempenho das cultivares IAC 2028 e Iris.

Efeito da adição de palha de cana-de-açúcar e da aplicação de vinhaça ao solo no desenvolvimento inicial de três cultivares de mamona

The experiment aimed to verify whether the addition of sugarcane mulch residue and vinasse on soil could affect seedling emergence and the initial development of three castor bean cultivars. The experiment was carried out using pots with soil, inside a glasshouse, in Campinas, State of Sao Paulo, Brazil, and arranged in randomized complete blocks with four replications. A three way combination of quantities of sugarcane (Saccharum spp) cv SP 803280 mulch residue equivalent to 0, 5, 10, 15 and 20 t.ha-1, quantities of vinasse equivalent to 0 and 150 m3.ha-1 and the castor bean cultivars IAC-Guarani, Iris and IAC-2028 were evaluated. Each day for 30 days, seedling emergence was counted and at the end, the speed of emergence index (SEI) and the final percentage were calculated. It was concluded that the application of vinasse decreased the seedling emergence of the castor bean cultivars IAC-Guarani, Iris and IAC-2028 but there was no damage in the seedling development with this residue. The addition of sugar cane mulch residue did not affect emergence but increased the initial development of castor bean cultivars.

Preservation of Tabebuia chrysotricha seeds as a function of seed water content and storage temperature

O ipe-amarelo (Tabebuia chrysotricha (Mart. ex A. DC.) Standl.) e uma especie arborea de alto valor ecologico, economico e paisagistico. Suas sementes apresentam variacao significativa na qualidade durante o armazenamento, o que representa dificuldades no desenvolvimento de tecnicas de propagacao. O objetivo desta pesquisa foi estudar o comportamento fisiologico das sementes de ipe-amarelo durante o armazenamento atraves de variacoes no teor de agua das sementes e na temperatura do ambiente. Frutos colhidos manualmente de plantas matrizes foram colocados para secagem e posterior extracao das sementes. Primeiramente, foi determinado o teor de agua inicial do lote e, paralelamente, obtida a porcao com o maior teor de agua a ser estudado (21,1%). Em seguida, as sementes remanescentes foram submetidas a secagem, em secador com circulacao forcada de ar a 28 ± 2oC, por diferentes periodos, obtendo-se teores de agua de 15,9, 13,6, 11,9 e 8,5%. As porcoes correspondentes aos diferentes teores de agua foram armazenadas a -12, 10 e 20oC. No inicio e a cada 30 dias ate 270 dias de armazenamento, as sementes foram submetidas as avaliacoes de teor de agua, germinacao, emergencia, velocidade de emergencia e comprimento da parte aerea. O mais alto e o mais baixo teor de agua estudado (21,1% e 8,5%) sao prejudiciais a qualidade fisiologica das sementes mesmo a temperatura extremamente baixa (-12oC) de armazenamento. A conservacao das sementes de ipe-amarelo (Tabebuia chrysotricha) e favorecida quando armazenadas com teor de agua em torno de 11,9% nas temperaturas de 10 e -12oC.

Temperatura, nitrato de potássio e fotoperíodo na germinação de sementes de Hypericum perforatum L. e H. Brasiliense Choisy

Hypericum perforatum L. and H. brasiliense Choisy, both belonging to the Clusiaceae family, are plant species of remarkable medicinal value. The former is commercially grown in Europe, and widely used as a phytotherapic for depression treatment while the latter, native to Brazil, has been recently studied as to its similar pharmacological potential. In this research work, seeds of both species were investigated as to the trait 1.000 seeds weight and the effects of several germination conditions (four temperature regimes: 20, 25, 30 and 20-30 oC), presence or absence of light; presence or absence of 0.2% potassium nitrate in the seed germination medium. The results for 1.000 seeds weight were 0.13 g (7,692 seeds/g) and 0.02 g (50,000 seeds /g) for H. perforatum and H. brasiliense, respectively. The highest seed germination rate increases were observed with the following temperature regimes: 20 oC or 20-30 oC (H. perforatum) and 30 oC (H. brasiliense). White light was required for seed germination in both species; moreover, light effect was more pronounced in H. brasiliense. In H. perforatum the light effect was strongly marked only at 20-30 oC while in H. brasiliense it was present in all studied temperature regimes. Germination substrate moistening with potassium nitrate was effective for H. brasiliense but did not affect H. perforatum seed germination.

Efeitos de diversos níveis de umidade e tratamento fungicida, na longevidade de sementes de amendoim

The effects of five moisture content on the longevity of mechanically shelled peanut seeds treated and not treated with fungicide were studied. The seeds were placed in hermetically sealed glass jars and stored in an unconditioned room in Campinas, State of Sao Paulo for a period of up to 22 months. The rate of deterioration was measured by the standard germination test. The 8.0 and 9.1% moisture content were extremely damaging to the longevity of the seeds including to those treated with fungicide. Seeds with the original moisture (7.0%) and treated with fungicide maintained reasonably well the germinability until nine months storage when they provided a percent germination around 60%. Seeds with 4.5 and 6.0% moisture content stored longer than those with higher moisture contents. At 14, 18, and 22 months storage seeds with 4.5% moisture content produced germination percentage significantly greater than those with 6.0%. The percent germination of fungicide-treated seeds was always statistically higher than non-treated seeds.

ARMAZENAMENTO DE SEMENTES DE IPÊ-BRANCO: TEOR DE ÁGUA E TEMPERATURA DO AMBIENTE

Tabebuia roseo-alba is a tree species largely used in restoration of degraded diverse plant communities and permanent preservation areas, general landscaping and as wood building material. Its seeds present strong variation in quality during storage and also a short period of viability, which hampers its natural dispersal as well as the development of cropping techniques for this tree. Aiming to obtain some informations related to seed preservation, the objective of this research was to study the physiological performance of Tabebuia roseo-alba seeds during storage. Mature fruits were hand collected from mother trees and placed under shade for a short period of natural drying in order to allow easy seed removal. Soon after that, the seed moisture content was determined and a representative portion of the seed lot was removed to constitute the highest moisture level to be studied, which was 10.1%. The remaining seeds were then submitted to drying at 25 °C inside a glass desiccator containing silica gel (anhydrous calcium chloride) in order to obtain 8,3% moisture degree. The two portions, after being divided into five replications, were stored in chambers at 10, 20, and -20 °C. At the beginning (freshly collected seeds) and at 60, 120, 180, 240, 300 and 360 days of storage, the seeds were submitted to the following physiological evaluations: germination, seedling emergence, speed of emergence, and length of the above ground seedling part (hypocotyl). The experiment was a completely randomized design, with two treatments (degrees of moisture) at the beginning of storage and six treatments (2 moisture levels x 3 thermal conditions), in each evaluation period, during storage. Means were compared by the Tukey test at 5%. The preservation of Tabebuia roseo-alba seeds, considering the moisture contents of 10.1% and 8,3%, is favored by storage temperatures of 10 and -20 °C.

Efeito da palha de cana-de-açúcar e do tamanho do tubérculo na brotação e no desenvolvimento da parte aérea de tiririca

The Sao Paulo State Legislation established a gradual increase in the use of mechanical sugar cane harvest, which leaves a thick layer of straw, possibly affecting the development of purple nutsedge. Purple nutsedge (Cyperus rotundus L.) is one of the most crop-damaging weeds, infesting wide areas mainly in tropical and sub-tropical regions, causing substantial yield losses. It is considered one of most important weeds in sugar cane crop, by interfering directly on plant development, competing for essential growth factors (such as water, light, and nutrients) and by releasing allelopathic substances. There are few works about the effect of tuber size of weed species on the germination and development of plants. This experiment aimed to verify if the addition of sugar cane straw could affect the development of the aboveground part of purple nutsedge derived from tubers of small (0,2 to 0,3 g) and large (1,0 to 1,1 g) sizes, planted at three different times of the year. The experiment was set up in a greenhouse in Campinas, State of Sao Paulo, arranged in a randomized block design with four replicates. Dormant purple nutsedge tubers of small and large sizes were planted in May, July and September, and RB 855156 sugar cane straw was added in quantities corresponding to 0,0, 5,0, 10,0 and 15,0 ton/ha. Every 28 days until 84 days after each planting, the number of emerged sprouts, average plant height, foliar area and fresh and dry leaf and total aboveground part (leaves + inflorescences) weights were evaluated. The tubers planted in May emerged sooner and more uniformly than those planted in July and September. The number of emerged sprouts was not affected by tuber size. On the other hand, plant height, leaf area, and fresh and dry leaf and aboveground part weights were larger when originated from large-sized tubers. The addition of sugar cane straw to the soil affected more the plants derived from small than from large tubers. It was verified that, with the exception of average height, the September planting originated plants with larger number of sprouts, leaf area, fresh and dry leaf and total aboveground part weights. Larger average plant height values were observed in the May planting. For all analyzed variables, the July planting presented always the smallest values. The application of increasing quantities of sugar cane straw caused a decrease in the number of sprouts, foliar area, and fresh and dry leaf and total aerial aboveground weights. The number, leaf area, and average plant height of the sprouts, and the fresh and dry leaf and total aboveground part weights increased linearly as function of time.EFFECT OF SUGAR CANE HARVEST STRAW AND TUBER SIZE ON SPROUTING AND SHOOT GROWTH OF PURPLE NUTSEDGE (CYPERUS ROTUNDUS L.) The Sao Paulo State Legislation established a gradual increase in the use of mechanical sugar cane harvest, which leaves a thick layer of straw, possibly affecting the development of purple nutsedge. Purple nutsedge (Cyperus rotundus L.) is one of the most crop-damaging weeds, infesting wide areas mainly in tropical and sub-tropical regions, causing substantial yield losses. It is considered one of most important weeds in sugar cane crop, by interfering directly on plant development, competing for essential growth factors (such as water, light, and nutrients) and by releasing allelopathic substances. There are few works about the effect of tuber size of weed species on the germination and development of plants. This experiment (1) Recebido para publicacao em 13 de dezembro de 2004 e aceito em 3 de janeiro de 2006 (2) Instituto Agronomico (IAC), Caixa Postal 28, 13001-970 Campinas (SP). E-mail mcdesalvo@hotmail.com; (3) ESALQ-USP, Caixa Postal 9, 13418-900 Piracicaba (SP). E-mail rvictori@esalq.usp.br (4) Faculdade de Ciencias Biologicas, PUCCampinas, Av. John Boyd Dunlop, sn, 13059-900, Campinas (SP). M.C. S. S. Novo et al. Bragantia, Campinas, v.65, n.1, p.97-107, 2006 98 aimed to verify if the addition of sugar cane straw could affect the development of the aboveground part of purple nutsedge derived from tubers of small (0,2 to 0,3 g) and large (1,0 to 1,1 g) sizes, planted at three different times of the year. The experiment was set up in a greenhouse in Campinas, State of Sao Paulo, arranged in a randomized block design with four replicates. Dormant purple nutsedge tubers of small and large sizes were planted in May, July and September, and RB 855156 sugar cane straw was added in quantities corresponding to 0,0, 5,0, 10,0 and 15,0 ton/ha. Every 28 days until 84 days after each planting, the number of emerged sprouts, average plant height, foliar area and fresh and dry leaf and total aboveground part (leaves + inflorescences) weights were evaluated. The tubers planted in May emerged sooner and more uniformly than those planted in July and September. The number of emerged sprouts was not affected by tuber size. On the other hand, plant height, leaf area, and fresh and dry leaf and aboveground part weights were larger when originated from large-sized tubers. The addition of sugar cane straw to the soil affected more the plants derived from small than from large tubers. It was verified that, with the exception of average height, the September planting originated plants with larger number of sprouts, leaf area, fresh and dry leaf and total aboveground part weights. Larger average plant height values were observed in the May planting. For all analyzed variables, the July planting presented always the smallest values. The application of increasing quantities of sugar cane straw caused a decrease in the number of sprouts, foliar area, and fresh and dry leaf and total aerial aboveground weights. The number, leaf area, and average plant height of the sprouts, and the fresh and dry leaf and total aboveground part weights increased linearly as function of time.

Tratamentos com fungicidas no comportamento de sementes de amendoim

As sementes de amendoim (Arachis hypogaea L.) sao especialmente vulneraveis a invasao fungica, causa frequente de estandes insatisfatorios e, consequentemente, de baixas producoes da cultura. A eficiencia dos fungicidas Captan, Thiram (TMTD), Benomyl, Quintozene (PCNB) e Thiabendazole, aplicados em sementes de amendoim do cultivar Tatu, foi estudada com relacao a emergencia de plântulas em casa de vegetacao, e a emergencia inicial, ao estande final e a producao de vagens no campo. Em todos os parâmetros, nao houve efeito de epoca nem de interacao fungicida x epoca de aplicacao. A vantagem do uso de fungicida ficou bem evidenciada, uma vez que as sementes tratadas apresentaram, em relacao as nao tratadas, emergencia de plântulas superior em casa de vegetacao e maiores valores de emergencia inicial, estande final e producao de vagens no campo. Os fungicidas mais eficientes foram Captan e Thiram. Resultados menos expressivos, porem ainda vantajosos se comparados com os da testemunha (sem fungicida), foram alcancados pela aplicacao de Quintozene (PCNB), Benomyl e Thiabendazole.

Influência do tamanho e umidade do grão na expansão da pipoca South American Mushroom

Utilizando sementes do cultivar de milho-pipoca South American Mushroom, obtido em 1984/85 em Campinas, SP, procurou-se avaliar os efeitos do teor de umidade e tamanho de grao na expansao da pipoca. Foram empregados tamanhos de graos compreendidos entre as peneiras 14 e 18 e teores de umidade entre 9,4 e 19,8%. Os resultados mostraram que a capacidade de expansao foi maior nos graos menores e nos teores de umidade de 10,5 a 11,5%.

Germinação de sementes de algodoeiro deslintadas por diferentes métodos

Sementes de algodao do cultivar IAC 13-1 foram deslintadas por quatro diferentes metodos, a saber: mecanicamente, por acido sulfurico, por gas cloridrico e por flambagem. Apos selecao em mesa de gravidade, cada porcao relativa a um determinado metodo de deslintamento foi dividida em duas, sendo uma delas tratada com fungicida PCNB 75%, nas dosagens recomendadas pelos fabricantes. Apos o teste inicial de germinacao, as sementes foram armazenadas em ambiente de laboratorio e novos testes de germinacao foram feitos aos 3, 6 e 12 meses. Em todos os periodos de armazenamento as porcentagens de germinacao das sementes deslintadas por acido sulfurico e gas cloridrico foram superiores as das sementes deslintadas mecanicamente ou por flambagem que, por sua vez, foram iguais entre si ou com a flambagem ocupando posicao intermediaria. Em todos os periodos as porcentagens de germinacao das sementes tratadas com fungicida foram superiores as das sementes sem esse tratamento.