A produção de caqui no estado de São Paulo vem aumentando, sendo o seu cultivo uma boa alternativa para a diversificação de plantas frutíferas pelos produtores. O conhecimento sobre a fenologia e fixação de frutos das principais cultivares de caquizeiros em clima subtropical é de grande importância para o desenvolvimento de práticas culturais que visam uma boa produção, uma vez que em clima temperado a produção é instável pelas altas quedas fisiológicas de flores e frutos. Para isso avaliou-se o acúmulo de graus-dia em diferentes fases fenológicas das principais cultivares plantadas em São Paulo, em clima Cwa, e o efeito da aplicação de ácido giberélico na fixação dos frutos. Para atingir o ponto de colheita, a cultivar Fuyu necessita, após a poda, um acúmulo de 3650 graus-dia, Giombo e Rama-Forte 4559 graus-dia e Taubaté 4280 graus-dia. A queda fisiológica de frutos das quatro cultivares ocorre em até três meses após a antese, com o acúmulo médio de 2074 graus-dia. No período de queda fisiológica, para as quatro cultivares, há dois picos acentuados de abscisão de frutos, o primeiro após a queda de pétalas, com 298 graus-dia e o segundo 50 dias após a antese, com 913 graus-dia. A aplicação exógena de ácido giberélico incrementa a fixação de frutos de caqui nas cultivares Fuyu, Giombo, Rama-Forte e Taubaté, quando há ensacamento de flores. Para as cultivares Fuyu, Giombo e Rama-Forte a aplicação de 100 mg L-1 de ácido giberélico na florada, aumenta a fixação dos frutos em mais de 20%. Para a cultivar Taubaté a aplicação de 300 mg L-1 de ácido giberélico incrementa a fixação em mais de 30%. / The production of persimmon in the Brazilian state of São Paulo is increasing, as its cultivation is a good alternative for the diversification of fruit plants for farmers. The knowledge about the phenology and fruit set of the main persimmon cultivars in subtropical climates is of great importance to the development of agricultural practices aiming for a good production, as in temperate climates the production is instable due to the large physiological flower and fruit drop. Therefore, the accumulation of degree-days in different phenological phases of the main cultivars planted in São Paulo state, in a Cwa climate, was evaluated, as well as the effect of applying gibberellic acid on the fruit set. To reach the point of harvest, the cultivar Fuyu requires 3650 degree-days after pruning, Giombo and Rama-Forte 4559 degree-days and Taubaté 4280 degree-days. The phenological fruit drop of the four cultivars occurs up to three months after the anthesis, with a mean of 2074 degree-days. In the period of physiological fruit drop of the four cultivars, there are two accentuated peaks of fruit abscission, the first after the drop of petals, with 298 degree-days and the second 50 days after the anthesis, with 913 degree-days. The exogenous application of gibberellic acid increases the fruit set of the persimmons for the cultivars Fuyu, Giombo, Rama-Forte and Taubaté, with flowers being bagged. For the cultivars Fuyu, Giombo and Rama-Forte the application of 100 mg L-1 of gibberellic acid during blooming, increases the fruit set by more than 20%. For the cultivar Taubaté the application of 300 mg L-1 of gibberellic acid increases the fruit set by more than 30%.

Almonds are one of the first commercial nut trees to bloom in early spring and thus are susceptible to temperature patterns prior to and during bloom which affect bloom timing, bloom length, pollination and nut set. Data used in this project include yearly dates of 90% bloom from 1996-2006, bloom length in days and final crop yields in pounds per tree for Nonpareil and Mission varieties. Data were collected from the University of California Cooperative Extension reports on the 1993-2006 Regional Almond Variety Trials in Butte, San Joaquin and Kern Counties. Temperature pattern models in the form of Chill Hours (Chill Hour Model), Chill Units (Chill Unit Model), Chill Portions (Chill Portion Model) and Growing Degree Hours (GDH°) (Heat Model) prior to bloom were used to predict the date of 90% bloom for each variety, site and year. Temperature model results were compared to averaged actual dates of 90% bloom by site and variety used to predict bloom timing (Calendar Model). The relationship between bloom length in days and GDH° during bloom and the relationship between bloom length, GDH° during bloom and final crop yields were also evaluated. The average error in predicting the 90% bloom date for both Nonpareil and Mission was smaller using the Calendar Model compared to the four temperature pattern models. The Chill Portion model did not have significantly higher average error in predicting the date of 90% bloom than the Calendar model in Nonpareil. The Chill Unit and Chill Portion models had smaller errors in predicting 90% bloom date than the Chill Hour or GDH° model in Mission. GDH° during bloom was positively correlated with bloom length. GDH° during the first four days of Nonpareil bloom was significantly correlated with crop yields, with each additional GDH° during bloom correlated with a 0.4 lbs./tree increase in crop yield. Further research is needed on specific temperature thresholds and their relationship to physiological changes during almond bloom and pollination. The practice of monitoring chilling and heat accumulation will allow growers to anticipate bloom, prepare to optimize bee activity during bloom, and plan for possible crop yield variations due to adverse weather conditions during bloom in almonds.

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The effect of temperature on fruit and achene characteristics of day-neutral strawberries were tested by two field experiments in Florida and Ontario, and one controlled-environment experiment. The results suggested that fruit became smaller as weather became hotter. This was mainly caused by ovule number and fruit volume/ovule which were determined before flowering. Fruit volume was determined by cell number and cell size. The cell number was determined before flowering, and after flowering there are a constant number of cell divisions. Cell volume plays a relatively minor role on fruit volume and cool temperature increased cell volume. Ovule number was determined 462 degree days before flowering and 14°C appeared to be the optimum temperature for ovule initiation. When there was a smaller proportion of developed achenes, the achenes appeared to be larger and have a similar contribution to fruit development than when there was a larger proportion. ‘Albion’ performed better in Florida, whereas ‘San Andreas’ performed better in Ontario.

The vine mealybug, Planococcus ficus (Signoret) (Homoptera: Pseudococcidae) is a pest with significant economic impact on the grape growing industry in South Africa and other parts of the world. With the isolation and synthesizing of the vine mealybug sex pheromone in 2001, new control options for the integrated management of the vine mealybug have been created. The status of sex pheromone monitoring as a tool in the integrated management of the vine mealybug has been evaluated from different perspectives. A significant quantitative difference in male vine mealybug trap catch numbers has been observed between wine and table grape vineyards and results indicated that there were differences in the susceptibility of grape cultivars to vine mealybug. Currently, the delta trap design is the accepted trap design for vine mealybug monitoring. No studies have yet been conducted to determine the optimum trap parameters like size or design. Population pressure may have an influence on the qualitative efficiency of various trap designs. The basis for degree-day forecasting models has been established adequately. However, refinements need to be done and the incorporation of factors such as humidity and regionality also need to be considered. Daily maximum temperatures fluctuating around the upper developmental threshold temperature for prolonged periods of time seemed to suppress population numbers. Different vineyard management practices exist for wine and table grape production. While an action threshold of 65 vine mealybug males per trap per two-week period seems an acceptable threshold for table grape production, it may not be appropriate for wine grape (or raisin grape) production. Using sex pheromone traps for population monitoring is a valid technique in the arsenal of management tactics against the vine mealybug. However, refinements and validation of research results must be done further to build credibility into the monitoring system. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2006.

An investigation of permafrost (permanently frozen soil) was conducted in Canada’s subarctic region of Northern Ontario. Environmental baseline conditions and permafrost states were estimated using seasonal freezing and thawing energies based on observed climate data and the Stefan equation. Field studies provided measurements of the active layer depths and validated the permafrost states; laboratory studies of the soil samples provided characterization for organic materials that have high affinity for soil moisture. Palsas (unique dome-like formations) were observed to have enhanced permafrost cores beneath a thermal insulating organic layer. With climate change, results suggest the possibility of shifts from the classification of continuous to discontinuous permafrost states in areas lacking the presence of organic materials that can have environmental and ecological impacts. Northern infrastructures may become destabilized with the degradation of permafrost while palsas may become lone permafrost refuges for biodiversity that depend on cooler ecosystems, such as polar bears.

An investigation of permafrost (permanently frozen soil) was conducted in Canada’s subarctic region of Northern Ontario. Environmental baseline conditions and permafrost states were estimated using seasonal freezing and thawing energies based on observed climate data and the Stefan equation. Field studies provided measurements of the active layer depths and validated the permafrost states; laboratory studies of the soil samples provided characterization for organic materials that have high affinity for soil moisture. Palsas (unique dome-like formations) were observed to have enhanced permafrost cores beneath a thermal insulating organic layer. With climate change, results suggest the possibility of shifts from the classification of continuous to discontinuous permafrost states in areas lacking the presence of organic materials that can have environmental and ecological impacts. Northern infrastructures may become destabilized with the degradation of permafrost while palsas may become lone permafrost refuges for biodiversity that depend on cooler ecosystems, such as polar bears.

Orientador: Helenice de Oliveira Florentino Silva / Banca: Dinival Martins / Banca: Vanderlei Marcos do Nascimento / Resumo: O Brasil é um grande produtor agrícola. Os dados do Levantamento Sistemático da Produção Agrícola (LSPA), divulgados pelo Instituto Brasileiro de Geografia e Estatística (IBGE), mostram uma previsão de 158,7 milhões de toneladas para a safra brasileira em 2011, um volume 6% maior que o recorde de 149,7 milhões de toneladas colhidas em 2010. Nos últimos anos a produção tem crescido e a área apta para plantio ainda não foi totalmente utilizada e estima-se que está sendo usada metade da área adequada para a agricultura. Esta grande produção se deve, em grande parte, ao clima do país, pois apesar das variações atuais de temperatura, o Brasil ainda possui um clima adequado para o cultivo de um grande número de espécies. Outro fator que tem sido relevante para o crescimento da agricultura é a evolução na forma de produção, pois a utilização de tecnologia de ponta e de novas variedades tem participação fundamental no desenvolvimento agrário. Mas, as grandes dimensões do país, a rapidez no desenvolvimento e as intensas modificações climáticas, têm trazido grandes problemas técnicos, econômicos e administrativos. Assim, os gestores deste setor têm buscado o auxílio de técnicas matemáticas e computacionais na obtenção de estimativas e nas tomadas de decisões. A modelagem matemática pode ser utilizada como ferramenta para auxiliar a melhoria na precisão e conseqüentemente na rentabilidade agrícola. Este trabalho propõe o uso de técnicas para modelagem matemática da temperatura diária, visando determinar equações matemáticas que descrevam as temperaturas diárias de um modo satisfatório, de tal forma que as curvas descritas pelas equações, auxiliem no cálculo de Graus Dia, que é uma importante medida na área de produção agrícola. Uma aplicação deste procedimento é feito para a cultura da cana de açúcar / Abstract: Brazil is a large agricultural producer. The data in the Systematic Survey of Agricultural Production (LSPA), released by the Brazilian Institute of Geography and Statistics (IBGE), show a forecast of 158.7 million tonnes for the brazilian harvest in 2011, a volume 6% higher than the record of 149.7 million tons harvested in 2010. In recent years the production has grown and the area suitable for planting has not yet been fully used and it is estimated that is being used half the area suitable for agriculture. This large production is, in large part, to the climate of the country, because in spite of the variations of current temperature, Brazil still has a suitable climate for the cultivation of a large number of species. Another factor that has been important for the growth of agriculture is the evolution in the form of production, because the use of high technology and new varieties are also fundamental in agricultural development. But, the big dimensions of the country, the speed in the development and the intense climate changes, has brought a great many technical problems, economic and administrative. Thus, the managers of this sector has sought the aid of mathematical techniques and computational to obtain estimates and in making decisions. The mathematical modeling can be used as a tool to help the improvement in accuracy and consequently in agricultural profitability. This paper proposes the use of techniques for mathematical modeling of daily temperatures, in order to determine how mathematical equations to describe the daily temperatures in a satisfactory manner, so that the curves as described by the equations, help in the calculation of Degree-Day, which is a significant extent in the area of agricultural production. An application of this procedure is done for the culture of sugar cane / Mestre

Made available in DSpace on 2014-06-11T19:23:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-03-03Bitstream added on 2014-06-13T19:49:35Z : No. of bitstreams: 1 bianconi_a_me_rcla.pdf: 724071 bytes, checksum: e4d7c4d70181487635bf52b5b318a870 (MD5) / A germinação de sementes representa uma etapa crítica para a sobrevivência da maioria das fanerógamas. Composição de gases, temperatura e água são os principais fatores ambientais limitantes do processo de germinação. Entre esses, a temperatura e a água exibem maior grau de flutuação, tanto em escala temporal como espacial, no ambiente terrestre, funcionando como importantes sinalizadores ambientais para a semente. Os objetivos deste trabalho foram fornecer a caracterização básica dos padrões germinativos de quatro cultivares (Carioca comum, Iapar 81, IPR Graúna e IPR Uirapuru) de Phaseolus vulgaris L. (Fabaceae); determinar as faixas ótimas de germinação para cada cultivar (experimentos em gradiente térmico com água destilada); realizar experimentos com interação dos fatores temperatura e potencial osmótico com soluções de polietilenoglicol 6000, visando à aplicação de modelos matemáticos baseados nos conceitos de graus-dia, psi-dia e na combinação destes dois conceitos (modelo psi-graus-dia), para se efetuar a comparação da resposta germinativa de tais cultivares. A cultivar IPR Graúna apresentou a faixa ótima com maior variação de distintas temperaturas (nove temperaturas), baseando-se na velocidade média de germinação; contrastando com a Iapar 81, que não apresentou uma faixa ótima, mas sim um único ponto ótimo (32,6ºC). Nenhuma das quatro cultivares apresentou germinação acima de 38,2ºC nem abaixo de 10,3ºC nos experimentos em gradiente térmico (água destilada). As temperaturas base obtidas pelo modelo de graus-dia variaram de 8,4 a 9,2ºC. Os ajustes (todos os R2s ≥ 0,70) ao modelo psi-graus-dia foram adequados para todas as cultivares, tanto na faixa supraótima quanto na infraótima. Assim sendo, ainda que mais estudos sejam necessários para melhorar a qualidade dos ajustes obtidos em relação... / Seed germination constitutes a crucial phase in relation to the life cycle of plant species. The composition of gases, temperature and water availability are the main environmental factors that may hinder several germination processes. Temperature and water availability, for example, are able to fluctuate considerably and may act as environmental “status’ indicators to the seeds. The present work was aimed at furnishing a basic characterisation of the germination patterns of four Phaseolus vulgaris cultivars, viz. “Carioca comum’, “Iapar 81”, “IPR Graúna” and IPR Uirapuru; assessing the optimum range of germination for each cultivar; conducting experiments in which the effects of temperature and osmotic potential were simultaneously analysed in order to deploy mathematical models concerning the concept of degree-days (thermal time) with the aim of comparing the germination response of such cultivars. “IPR Graúna’ exhibited a wider optimum range of temperature (nine distinct values) and “Iapar 81” presented only one temperature value as the optimum temperature (32.6ºC). The four cultivars did not germinate at temperatures higher than 38.2ºC and lower than 10.3ºC. The base temperatures derived from the application of the thermal time models varied from 8.4 to 9.2ºC. Regarding the hydrothermal-time model, the quality of the data fitting were deemed to be adequate (R2s ≥ 0.70) both in the suboptimum range and in the supra-optimum range. Other researches should be conducted in order to corroborate the present findings; nonetheless, the common bean cultivars were able to be compared and contrasted and exhibited, on the whole, a relatively homogenous... (Complete abstract click electronic access below)

A cultura da videira \'Niagara Rosada\' apresenta grande importância em diferentes regiões produtoras, principalmente no estado de São Paulo. Para a produção dessa uva é fundamental a utilização da técnica cultural da poda, que pode ocorrer em diferentes épocas. Dessa forma o presente estudo teve como objetivo comparar o desenvolvimento da videira \'Niagara Rosada\' podada em diferentes épocas mediante a análise de características como o comprimento dos ramos, velocidade média de crescimento de ramos, duração em dias de cada período do ciclo produtivo e soma térmica em graus-dia (GD). As épocas de poda adotadas foram de inverno, com realização em 04/08/2010 e de verão, com realização em 28/01/2011. O delineamento estatístico utilizado foi o de blocos ao acaso com 7 e 8 unidades experimentais cada, totalizando 30 unidades. Cada bloco foi uma planta e a unidade experimental foi um ramo. Para a análise de médias foi empregado o teste de Tukey para comparar os tratamentos de poda de inverno e poda de verão. As variáveis foram comparadas em relação aos períodos do ciclo produtivos: poda à colheita, brotação à colheita, poda à brotação, brotação ao florescimento, florescimento ao início da maturação dos frutos e início da maturação dos frutos à colheita. Houve resultado significativo em todas as comparações entre os tratamentos, de forma que se confirmou que em relação ao tamanho dos ramos, a poda de inverno apresentou ramos mais compridos do que a poda de verão. Em relação à velocidade média de crescimento dos ramos, esta foi superior na poda de inverno do que o observado na poda de verão. Já na duração do ciclo produtivo, houve maior duração no início do ciclo na poda de inverno e maior duração no final do ciclo na poda de verão, de forma que no ciclo como um todo a duração foi praticamente a mesma. Finalmente para a soma térmica, a poda de inverno apresentou valores superiores em todo o ciclo, excetuando-se o período do florescimento ao início da maturação dos frutos, em que a poda de verão apresentou valores superiores. / The importance of the \'Niagara Rosada\" crop is major in several regions, especially in the state of São Paulo. In the production of this vine tree the use of pruning is essential, which can occur in several seasons. With that in mind, this study has as objective to compare \'Niagara Rosada\' vine tree\'s development under different pruning seasons by analyzing characteristics as the length of the branch, average branch growth velocity, duration in days of the production cycle and degreedays (DD). The adopted pruning seasons were the winter pruning, being done in 08/04/2010, and the summer pruning, being done 01/28/2011. As experimental plot were use 4 plants, with 7 or 8 branches each, with the total of 30 branches. To analyze the results was used the Tukey test, comparing the treatments in the different periods of the production cycle (Pruning to Harvest, Sprout to Harvest, Pruning to Sprout, Sprout to Flowering, Flowering to Early Ripening and Early Ripening to Harvest. There was a significant difference between the treatments in all the comparisons. For the length of the branches, the winter pruning showed bigger branches in all the periods than the length of the summer pruning. As for the average branch velocity, it was superior in all the periods in the winter pruning. When considering the duration in days of the periods of the production cycle there was, in the beginning, a longer duration in the winter pruning an a longer duration in the end of the cycle for the summer pruning. When considering the total duration both treatments presented almost the same number. Finally, for the degree-days, the winter pruning showed a bigger rate in all the cycle, except in the Flowering to Early Ripening period, in which the summer pruning showed a bigger rate.