João Tessarioli Neto

Capacidade produtiva de cultivares de berinjela

The yield capacity of seven hybrids (Napoli, Diamante Negro, Cica, F-100, Super F-100, Kiko and F-2000) and two cultivars of open pollination were determined (Suzuki and Florida Market). The experiment was laid out in a randomized block design with three replicates and eight plants per plot. The planting distances were 1,5 x 1,0 m. Cultivar Suzuki produced higher number of fruits per plant (27 fruits), being different from Florida Market (13 fruits). The hybrids presented 20 to 25 fruits per plant. There was no difference between the number of fruits of first and second category. Florida Market and Kiko presented the highest fruit mass (362.5 and 358.7 g, respectively), differing from cultivar Suzuki, that presented the lowest fruit mass (178.9 g). Hybrid Kiko presented the highest yield per plant, differing significantly from Suzuki. Kiko, Diamante Negro, Cica and F-2000 presented yield potential similar to Napoli.

DESENVOLVIMENTO DE MUDAS DE QUIABEIRO [Abelmoschus esculentus (L.) Moench] EM DIFERENTES TIPOS DE BANDEJA E SUBSTRATO

Devido as vantagens que o sistema apresenta, a producao de mudas utilizando bandejas de isopor, cada vez mais vem sendo utilizada no estado de Sao Paulo. O sistema proporciona maior cuidado na fase de germinacao e emergencia, fazendo com que, muitas vezes, uma semente origine uma planta, alem de proporcionar menor custo no controle de pragas e doencas e alto indice de pegamento apos o transplante. Com o objetivo de avaliar o desenvolvimento de mudas de quiabeiro, cultivar Santa Cruz - 47, produzidas no sistema de bandejas de isopor, montou-se um experimento, em ambiente protegido. Foram comparados tres tipos de bandeja, que diferiam entre si pelo volume a altura das celulas, associadas a quatro diferentes substratos. Os substratos constaram de variacoes de uma mistura comercial, produzida pela Empresa Gioplanta. O delineamento experimental foi de blocos inteiramente casualizados, com 4 repeticoes, no esquema fatorial 3X4. Para as condicoes do experimento concluiu-se que as bandejas de maior volume proporcionaram melhor desenvolvimento das mudas de quiabeiro para todos os parâmetros estudados. No substrato que recebeu casca de arroz carbonizado na proporcao 1:1, observou-se menor desenvolvimento das mudas. A utilizacao do produto comercial (adubado) com suplementacao de nutrientes favoreceu o desenvolvimento das mudas de quiabeiro.

QUALIDADE FISIOLÓGICA E TAMANHO DE SEMENTES DE CENOURA

Maturation of carrot seeds occurs in a sequence based on the different orders of the umbel. Since harvest is carried out only at one stage, nonuniform seed sizes within the same seed lot may occur. The effect of seed size on physiological quality was determined. Four lots of commercial carrot seeds (cv. Brasilia) were separated in three fractions: large (retention at 2 mm diameter); medium (retention at 1.5 mm diameter) and a mixture of large and medium seeds (1:1 proportion). These fractions were tested for germination, tetrazolium reduction, electrical conductivity, accelerated aging and seedling emergence. Only seedling emergence, evaluated after 14 days, showed statistical difference. However this test did, not show consistency for the separation of the fractions into different quality levels, for different lots.

Produção de frutos de quiabeiro a partir de mudas produzidas em diferentes tipos de bandejas e substratos

Com o objetivo de avaliar a producao comercial de frutos de quiabeiro a partir de plantas originadas do transplante de mudas, instalou-se um experimento na ESALQ em Piracicaba. Na producao de mudas, que ocorreu em ambiente protegido, foram utilizados tres tipos de bandeja, que diferiam entre si pela altura e volume das celulas, associadas a quatro diferentes substratos, que eram variacoes de uma mistura comercial (denominada GII). O delineamento experimental foi de blocos ao acaso, com quatro repeticoes, no esquema fatorial 3x4 (tres tipos de bandeja e quatro variacoes do substrato), perfazendo um total de doze tratamentos. Foram transplantadas 30 mudas/tratamento, obedecendo ao espacamento de 0,5x1,0 m. Cada parcela experimental foi constituida por cinco fileiras de 3,0 m de comprimento totalizando a area de 15 m2. A colheita foi iniciada 49 dias apos o transplante, sendo colhidos frutos de tamanho comercial (8 - 10 cm de comprimento) das doze plantas centrais. Foram avaliados numero e peso total dos frutos. Foi observada maior produtividade em plantas originadas de mudas provenientes das bandejas de maior tamanho, independentemente do substrato utilizado. A menor produtividade ocorreu quando no substrato foi adicionado casca de arroz carbonizada na proporcao 1:1 ao produto comercial GII, independentemente do tipo de bandeja utilizada.

Onion seedling production in styrofoam trays under controlled environment, as summer-planted onions

Uma das dificuldades do cultivo do verao da cebola (Allium cepa L.), que permite maior lucro pois esta e a epoca de entressafra, e a producao de plantas para o transplante. Com o objetivo de verificar o comportamento na fase de muda do hibrido Mercedes, sob cultivo protegido como cultura de verao, o experimento foi instalado em estufa, em Piracicaba, SP com bandejas de isopor de 288 celulas. Foram testados quatro substratos. e dois numeros de plantas por celulas (3 e 4 plantas/celula), sendo sub-plot a suplementacao mineral com nitrogenio 2 e 3 vezes por semana com nitrato de calcio + nitrato de potassio. O delineamento experimental foi inteiramente casualizado, com fatorial 4 x 2 em parcelas subdivididas, e tres repeticoes. A densidade de tres plantas por celula apresentou menor taxa de bulbificacao precoce e maior altura da planta; nao houve diferenca quanto aos substratos e que a aplicacao de nitrogenio tres vezes por semana apresentou os maiores valores de altura da planta e peso da materia seca da parte aerea, nao apresentando bulbificacao precoce das plantas.

Produção de mudas de cultivares de morangueiro em duas épocas de coleta

In spite of the great importance of runners in the formation of new strawberry fields, little importance has been given to experimental studies of this phase of the crop. There were evaluated seven strawberry cultivars in the stage of runner production, during two different collection dates under field conditions, in Piracicaba, Brazil. The experimental design was completely randomized with 14 treatments and 4 replications, using a factorial scheme of 7 x 2. The variables were the cultivars (Campinas IAC-2712, IAC Princesa Isabel, Chandler, Dover, Pajaro, Toyonoka and Korona) and the dates of runner collection (14/031997;15/04/1997). The runners were considered according to four categories: Extra, First, Second, Discarded. The number of runners produced in one square meter was also evaluated. Significant differences were found for the number of runners produced per square meter for the different cultivars. Dover and Campinas produced higher number as compared to cultivars Korona, Chandler, Princesa Isabel, Toyonoka and Pajaro, independently of the collection date. The quality of the runners collected in the second date (15/04/1997) was better in relation to those collected in the first date (14/03/1997), independently of the cultivar.

Fisiologia de mudas de morangueiro produzidas em sistema convencional e em vasos suspensos

A utilizacao de um sistema adequado para a conducao das plantas-matrizes fornecedoras de mudas e de fundamental importância, tanto com a finalidade de favorecer a quantidade de mudas produzidas, como para a qualidade das mesmas; por outro lado, a disponibilidade de mudas em periodos nao convencionais de plantio, atraves da utilizacao da frigoconservacao, possibilita a producao de frutos na entressafra, propiciando maiores ganhos pelos produtores devido aos melhores precos alcancados. Os presentes trabalhos tiveram como objetivos comparar o sistema de producao de mudas de morangueiro convencional com o de producao em vasos suspensos, assim como avaliar a frigoconservacao em mudas produzidas em sistema de vasos suspensos. Avaliaram-se a materia seca, os teores de carboidratos nas mudas e a percentagem de sobrevivencia das mesmas apos o transplante para local definitivo. No primeiro trabalho, foi utilizado o delineamento inteiramente ao acaso, em esquema fatorial 3x2 (tres cultivares: Campinas, Pelican e Guarani; e dois sistemas de producao de mudas), com tres repeticoes de 30 mudas; no segundo trabalho, utilizou-se o delineamento experimental inteiramente ao acaso, com cinco cultivares (Campinas, Dover, Pelican, Sequoia e Sweet Charlie) e nove repeticoes. Neste ultimo trabalho, apos a coleta, as mudas foram acondicionadas em sacos de polietileno e frigoconservadas durante 120 dias em câmara fria (-1 ± 1oC). As mudas produzidas em vasos suspensos apresentaram maior percentagem de sobrevivencia e maiores teores de carboidratos totais, com resultados semelhantes para as tres cultivares estudadas. A frigoconservacao de mudas de morangueiro produzidas em sistema de vasos suspensos resultou em baixa percentagem de sobrevivencia de mudas no experimento.

Efeito da solarização do solo, seguida pela aplicação de Trichoderma spp. ou de fungicidas, sobre o controle de Pythium aphanidermatum e de Rhizoctonia solani AG-4

The development of alternative strategies for soil desinfestation with methyl bromide is necessary since the use of this compound faces increasing restrictions worldwide. Therefore the effect of soil solarization, followed by the application of isolates of Trichoderma spp. or fungicides, was evaluated for the control of Pythium aphanidermatum and Rhizoctonia solani, both can cause damping-off and root rots of several crops. Two experiments were carried out, one under greenhouse conditions and the other one under field conditions, both in a randomized block design, in factorial scheme (2x3), involving the combination of soil solarization (solarized and non-solarized soils) and the application of chemical or biological treatments, plus controls. Nylon bags containing soil naturally infested with P. aphanidermatum or soil with propagules of R. solani AG-4 were buried at 10 cm soil depth in plots solarized or non-solarized. After 30 days of solarization the bags were collected and the soil infested with P. aphanidermatum was treated with Trichoderma sp. (isolate IB-26) or with the fungicide metalaxyl + mancozeb, whereas the soil containing propagules of R. solani received an isolate of Trichoderma sp. (isolate IB-17) or the fungicide pencycuron. Fungicide suspensions were irrigated over the soil. A control was maintained for the soils infested with both pathogens. Viability of P. aphanidermatum and R. solani was evaluated by post-emergence damping-off of cucumber seedlings and by pre and post-emergence damping-off of radish seedling, respectively. Soil solarization, the biological treatment and the association of both treatments had no effect on the control of P. aphanidermatum, which was achieved only by the treatment with metalaxyl + mancozeb in the solarized and non-solarized soil. Soil solarization applied in both environments as well as the fungicide pencycuron were effective to control R. solani, but the association of both treatments did not have any synergistic effect. The treatment with the isolate of Trichoderma sp. IB-17 had no effect on R. solani, and was not favored by soil solarization.

Avaliação da solarização do solo para o controle de Ralstonia solanacearum

The use of soil solarization for the control of bacterial wilt, caused by Ralstonia solanacearum, was evaluated by burrowing nylon bags containing soil infested with the bacteria in plots solarized or not. Two experiments were carried out in Campinas (SP), from February to April/2001, and Piracicaba (SP), from December/2001 to February/2002. The experiments were set up in a completely randomized factorial design, with four replications, in 4 x 4 meter plots. The factors evaluated were soil solarization with a transparent plastic film 100 µm thick, period of treatment (30 and 60 days and 37 and 60 days for the first and second experiments, respectively) and, only for the second experiment, soil depth (10 and 20 cm). The soil of each nylon bag collected after the previously established solarization periods, was placed in pots where tomato (Lycopersicon esculentum) seedlings were transplanted. In the non-solarized soil, in both experiments, 43 to 100% of the tomato plants wilted. In the second experiment, 6 to 22% of the plants grown on the soil solarized for 37 days wilted. No wilted tomato plants were observed in the solarized plots of the first experiment nor in the soil solarized for 60 days, in both soil depths, of the second experiment. The results obtained indicate that soil solarization has potential for the control of R. solanacearum.

Avaliação de cultivares de berinjela em armazenamento refrigerado

Our objective was to evaluate the post-harvest behavior of nine eggplant cultivars. Fruits were stored at 11 + 0,5oC e 90 + 5% RH, for periods of 7, 14 and 21 days (including 2 days of simulated commercialization at 24-25oC and 70-75% RH). The cultivars studies were Diamante Negro, Kiko, Piracicaba F-100, Florida Market, Super F-100, F-2000, Suzuki, Napoli and Cica. We measured changes in weight loss, turgor pressure and visual quality during the cold storage period. Low temperature storage of the fruits was acceptable up to 7 days for all cultivars. Storage above 7 days was dependent of the cultivar. The cultivar Super F-100 presented the largest storage capacity.