The risks and profitability associated with four early planting dates, and three different types of bolting risk reduction strategies, were evaluated for Quebec celery production. The four planting dates studied were April 17 th, April 24th, May 1st and May 8 th. The impacts on yield if plants were harvested after eleven week, twelve, thirteen, and fourteen weeks in the field were investigated. The three risk reduction strategies considered were plants grown from planting until June 2nd with no row covers, under floating row covers of spunbonded polyester (Agryl P17, Plastitech) and under floating row covers made of clear, perforated polyethylene (Plastitech). The results suggest that the floating row covers can help plants reach the required market standards sooner that if no row covers were used from the planting date investigated until June 2nd. At the earliest two planting dates, the results suggest that row covers may significantly suppress bolting and allow greater yields at earlier harvest dates. The results also suggest that row covers may provide an advantage at later planting dates, as they may allow for the plants to reach marketable standards sooner. The results also suggest that there is a 50 percent chance of encountering bolting rate of 30 percent or higher if transplanting plants on April 17th. The row covers reduced the probability that plants will bolt to close to zero at for all four planting dates. The most profitable strategy was determined to be planting on April 17th, growing the plants under row covers made of spunbonded polyester (Agryl P17, Plastitech) from planting until June 2nd and then harvesting after the plants had been in the field for thirteen weeks.

Field experiments were undertaken to predict the yield of 'Earligold' muskmelon grown with plastic mulches, rowcovers and thermal water tubes. Mulches were either black, photoselective or clear. Rowcover systems included a clear perforated polyethylene, a polypropylene agrotextile, or unperforated polyethylenes (standard or infra-red treated) with a water-filled tube. In all tunnel types, the photoselective mulch had an intermediate effect between clear and black mulch on air and soil temperatures, chilling injury and days to flowering. Plants with a clear mulch and an infrared or standard unperforated tunnel with a thermal tube survived chilling temperatures between 1.6-5.8C for seven days, flowered first, had the heaviest biomass at anthesis and had the highest early yields. Plant dry weight from transplanting to anthesis was predicted from a multiple linear regression based on heat unit formulas using air (base temperature of 14C, maximum threshold of 40C) and soil temperatures (base temperature of 12C). The base temperature for predicting developmental time to anthesis of perfect flowers was 6.8C. In order to study fruit growth, a rapid and non-destructive method for estimating volume of ovaries was established. Fruit phenology was described as six classes for flower development and seven for fruit development. Flower abortion was studied in relation to each class. Plants displayed either one or two fruit growth cycles. The second cycle was triggered as the absolute growth rate of the first cycle fruits decreased. Developmental time of individual fruits was predicted from a heat unit formula with a base temperature of 15C when temperatures were recorded from a meteorological station. Another heat unit formula was proposed for air temperature at 7.5 cm. Fruit growth from the second cycle had a 60-degree day lag. Fruit volume proportion from blooming to maturity of first cycle fruits was described by a common Richards function. Although 65% of the plants produc

The use of plastic mulches in producing red bell pepper (Capsicum annuum L.) is relatively new to Quebec and management techniques need to be further developed in terms of nitrogen (N) fertilization as well as insect and disease control. A research project was undertaken in the 1995 and 1996 growing seasons to compare peppers grown on black and on silver mulches, and fertigated using either the conventional method (weekly N-fertigated) or N-fertigated using diagnostic chlorophyll meter readings. Both fertigation treatments resulted in similar yields, although those fertilized according to the chlorophyll meter received 28 to 42 kg N/ha less than the weekly fertilized treatments. The chlorophyll meter was able to detect N deficiencies. Alate aphid populations were significantly reduced by mulches, especially by the silver mulch in both years. However, apterous aphid populations were increased by mulches, most markedly by the black mulch. No significant effect of mulch or N was found on tarnished plant bug or European corn borer populations, or on the percentage of fruit with sunscald or viral symptoms.

Vernalized celery seedlings (Apium graveolens L. var. Florida 683) were predevernalized under different temperature and light regimes prior to field transplanting. At least 89% of predevernalized plants bolted during both 1999 and 2000 suggesting that the predevernalization treatments were not effective in counteracting the vernalizing stimulus. Predevernalization treatments had no long-term effect on growth and development. Non-vernalized celery seedlings were transplanted on clear polyethylene mulch, thermo-selective polyethylene mulch or no mulch in combination with clear perforated polyethylene mini tunnel, single or double layer of agrotextile mini tunnel or no mini tunnel. Very few plants bolted in 1999. Mulch increased fresh weight and number of celery leaves compared with controls. Plants grown on clear polyethylene mulch had significantly higher mortality rates than other treatments. Agrotextile mini tunnels reduced bolting to 0% in 2000. Mini tunnels, especially a single layer of agrotextile, increased fresh weight, plant height and stem diameter in 2000.

Experiments were conducted in 1997, 1998 and 1999 to determine the effects of mulch/mini-tunnel and thermal-water tube combinations on daily carbon dioxide (CO2) concentration, air, soil temperatures and early growth of muskmelons (var. Earligold) during the vegetative phase. Treatments consisted of mulched plot covered with a clear perforated, a clear non-perforated or a non-perforated infrared polyethylene mini-tunnel with the absence or the presence of a thermal-water tube compared with control treatments. Additional treatments consisting of the ventilation non-perforated clear and infrared tunnels containing no tube were used in 1998 and 1999. The non-perforated tunnels significantly increased CO2 concentrations, air and soil temperatures compared with those of perforated tunnels and controls. Inclusion of a thermal-water tube reduced air temperature fluctuations in the tunnels. Ventilating the non-perforated tunnels significantly decreased CO2 concentrations and air temperatures. / During the first 10--15 days after transplanting, muskmelons grown in the non-perforated tunnels had higher relative growth rate (RGR), net assimilation rate (NAR), and dry weight than those of grown under perforated tunnels and in the control plots. However, during the later period, 11--16 days after transplanting to anthesis, the effects of mulch/mini-tunnels on the RGR, NAR and dry weight of muskmelons were inconsistent. Muskmelons grown in the mulch/tunnels had significantly higher RGR, but generally lower NAR, than those of grown without tunnel. The use of mulch/mini-tunnels significantly increased dry weight at anthesis in 1997, but not in 1998 and 1999. The presence of thermal-water tube in the tunnels and ventilating the non-perforated tunnels generally increased RGR, NAR, and dry weight of muskmelons. The use of mulch/mini-tunnels reduced time for muskmelon to reach anthesis by 9 to 11 days. / The leaves of muskmelons grown in mulch/mini-tunnels had significantly lower ratios of variable to maximum fluorescence (Fv/Fm) than control plants throughout the experiments, except at 10 and 20 days after transplanting in 1997. Leaves of muskmelons grown in non-perforated tunnels had significantly higher levels of chlorophyll than all other treatments during first 15 days after transplanting. However, chlorophyll values in these treatments decreased as muskmelons reached anthesis. The presence of a thermal-water tube in the mulch/mini-tunnels and ventilating the non-perforated tunnels generally increased both Fv/Fm ratios and chlorophyll levels of muskmelon leaves.

Made available in DSpace on 2015-03-03T11:52:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-12-16Bitstream added on 2015-03-03T12:06:35Z : No. of bitstreams: 1 000813759.pdf: 1583557 bytes, checksum: f46082ed1de71c3bcfb41675b1258dd2 (MD5) / As condições ambientais são fundamentais para se produzir hortaliças com qualidade e com o uso do cultivo em ambiente protegido, passou-se a manejar o ambiente em favor da planta. Desde então, muitos produtores, no mundo todo, passaram a utilizar esta tecnologia, que possibilita a produção com maior qualidade e produtividade, o que tem sido atribuído em parte à maior quantidade de radiação solar difusa que ocorre neste ambiente. O polietileno de baixa densidade (PEBD), principal material utilizado na cobertura, transforma parte da radiação solar direta em difusa ao transmití-la para o interior do ambiente. Esta radiação é considerada mais eficiente. Visando-se explorar melhor este benefício, a indústria desenvolveu o plástico difusor de luz, que tem como principal característica transformar a radiação solar direta em difusa ao transmití-la para o interior do ambiente. No entanto, há poucos estudos com relação ao uso deste material, principalmente, quanto à transformação da radiação direta em radiação difusa e à densidade de plantas a ser utilizada. O objetivo deste trabalho foi avaliar algumas características fisiológicas e a produção de plantas de pimentão enxertado sob o plástico difusor de luz e em diferentes densidades de planta. O experimento foi conduzido na Fazenda Experimental de Pesquisa e Produção (FEPP) da UNESP/Botucatu em São Manuel – SP. Plantas de pimentão do híbrido Melina foram enxertadas sobre o porta-enxerto AF-8253 e foram transplantadas em três ambientes (PEBD comum (PEBDc), PEBD difusor de luz (PEBDd) e a campo) e três espaçamentos de plantas (1,50 m entre linhas e 20; 35 e 50 cm entre plantas). Os valores de transmissividade à radiação solar ... / Environmental conditions are fundamental to produce vegetables with quality. The use of protected cultivation, environment management has favored plants. Since then many growers worldwide have been utilizing this technology that enable production with better quality and yield which is partly due to the increase in diffuse solar radiation inside this environment. Low density polyethylene (LDPE), the main material utilized as cover, makes part of the direct solar radiation diffuse within the protected environment. This radiation is considered more efficient. Aiming to explore this benefit better, diffuse light plastic has been developed to transform great part of direct solar radiation into diffuse within a greenhouse. However, there are few studies related the use of this material, mainly regarding the transformation of direct solar radiation into diffuse, and regarding plant densities. The aim of this study was to evaluate some physiological characteristics of grafted sweet pepper plants inside light-diffuser plastic at different plant densities. The experiment was carried out at “Fazenda Experimental São Manuel” of FCA/UNESP in Botucatu-SP. Sweet pepper plants of Melina hybrid grafted on AF-8253 rootstock were utilized. Treatments consisted of three environments: one covered with common LDPE, another covered with light-diffuser LDPE, and the third one was an uncovered field production, and three spacings (150 cm between rows, and 20, 35 and 50 cm between plants). Values of global solar radiation transmissibility were 56.0 and 73.3% in light-diffuser LDPE and common LDPE, respectively. There was a small reduction in the transmissibility of photosynthetically active radiation compared to global radiation ...

Made available in DSpace on 2016-12-08T16:44:53Z (GMT). No. of bitstreams: 1 PGPV07MA018.pdf: 1882559 bytes, checksum: 51d66c33280cb2ec91823298a2b3e9cb (MD5) Previous issue date: 2007-02-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Serra Gaúcha in the state of Rio Grande do Sul is a traditional region for grapevine cultivation in Brazil. However, this location has a high pluviometric precipitation and a high relative humidity, mainly at the harvesting period, demanding an intensive treatment of grapevines with agrochemicals. This increases substantially the production costs. Therefore, grapes are normally harvested in advance to avoid losses by rots at the rainy periods, but this affects grapes quality for in natura consumption and processing. The impermeable translucent plastic cover (ITPC) represents an opportunity to protect the plants from adverse climatic conditions and to reduce agrochemical treatments, therefore improving the grapes quality for vinification. As a result of its optical and water proof properties, the ITPC change the microclimatic conditions, with the reduction of photosynthetically active radiation (FAR) and water availability, besides of increasing air temperature under the cover. This research was carried out to study the impacts of an ITPC on vegetative growth, yield, water availability, leaf chlorophyll content, and gas exchange of grapes Cabernet Sauvignon (Vitis vinifera L.). Five years old grapevines grafted on Paulsen 1103 rootstock were raised as Y training. The experiment followed a casualized block design, with two treatments (covered and uncovered grapevines) and four replications of 15 plants. The microclimatic condition imposed by the ITPC did not change the grapevines phenology. The grapevines under the ITPC had lower number of leaves per plant, higher length and fresh mass of shoots, and higher leaf dry mass than the uncovered grapevines. Grapes weight and diameter were higher for covered grapevines only at the early developmental stages but they did not differ from uncovered grapevines at the harvest. The water availability at the superficial soil layers was lower for plants covered with the ITPC, but this did not affected the leaves basal water potential and potential photosynthesis in comparison to the uncovered grapevines. Covered grapevines had higher leaf absolute chlorophyll content and higher stomatal conductance than uncovered grapevines. The ITPC reduced the PAR and the water availability at the superficial soil layers, but this did not affect yield and leaves basal water potential and CO2 net assimilation / A Serra Gaúcha é uma região que apresenta tradição no cultivo da videira no Brasil. Todavia, possui elevado índice pluviométrico e alta umidade relativa do ar, principalmente na época de colheita, exigindo um rigoroso controle fitossanitário, o que eleva o custo de produção. Em muitos anos as safras são antecipadas, com o intuito de evitar perdas por podridões favorecidas pela precipitação, comprometendo assim a qualidade final da uva tanto para consumo in natura como para processamento. A cobertura plástica translúcida e impermeável (CPTI) surge como uma alternativa para o controle das adversidades climáticas e diminuição do uso de agrotóxicos, melhorarando assim a qualidade da uva para a vinificação. Devido as suas características ópticas e de impermeabilidade à água, a CPTI altera as condições microclimáticas, como a redução da radiação fotossinteticamente ativa (RFA) e da disponibilidade hídrica, podendo ainda elevar a temperatura do ar sob a cobertura plástica. O objetivo deste estudo foi avaliar os impactos de uma CPTI sobre o crescimento vegetativo, produção, disponibilidade hídrica, teores foliares de clorofilas e trocas gasosas em videiras Cabernet Sauvignon (Vitis vinifera L.). As plantas com cinco anos de idade foram conduzidas em sistema Y , sobre porta-enxerto Paulsen 1103. O experimento seguiu o delineamento em blocos ao acaso, tendo como tratamentos a presença e a ausência da CPTI, com quatro repetições de 15 plantas (unidade experimental). As alterações microclimáticas impostas pela CPTI não alteraram o comportamento fenológico da videira. As plantas, sob CPTI, mostraram-se com menor número total de folhas por planta, maior comprimento e massa fresca de ramos e massa seca foliar em comparação às plantas descobertas. O peso e o diâmetro de bagas foram superiores nas videiras cobertas apenas no inicio do ciclo e não diferiram próximo da colheita. A disponibilidade hídrica do solo nas camadas superficiais, obtida através da umidade volumétrica, foi menor no solo com o uso da CPTI, mas isto não alterou o potencial hídrico foliar de base e a fotossíntese potencial na comparação com a área sem CPTI. As plantas cobertas apresentaram maiores valores absolutos de teores foliares de clorofilas e de condutância estomática em relação às plantas sem cobertura. A CPTI reduziu a RFA e a disponibilidade hídrica nas camadas superficiais do solo, sem, no entanto, comprometer a produção, o potencial hídrico foliar de base e a assimilação foliar de CO2

Orientador: Maria Angela Fagnani / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-08T16:23:09Z (GMT). No. of bitstreams: 1 Martins_JoseLuis_D.pdf: 2290824 bytes, checksum: 16399689f4aee5a0a7128cc47568b1e6 (MD5) Previous issue date: 2006 / Resumo: O objetivo deste trabalho foi avaliar um filme para cobertura de casa de vegetação através dos aspectos de produção e qualidade; elementos micrometeorológicos e de envelhecimento do filme plástico, sob as condições impostas pela cobertura plástica com diferentes anos de uso. Para a produção e qualidade foram selecionados 15 vãos de estufa, com plástico de ano de início de uso 1998, 1999, 2002 e 2003 e mais a testemunha com três repetições cada. Dois manejos de produção foram utilizados para a avaliação: o manejo comercial usado na propriedade (primeira etapa) e um manejo específico (segunda etapa) em que houve um corte raso, no início do experimento, em uma área de 1m2 realizado no intuito de avaliar o desenvolvimento do botão floral da poda até a haste comercial pronta. Na primeira etapa foram realizadas 4 coletas ao longo do período do experimento (nos dias 01/03/2004, 17/03/2004, 26/03/2004 e 05/04/2004). Na segunda etapa foi avaliado o aparecimento dos botões florais dos novos brotos em quatro datas (20/02/2004, 07/03/2004, 26/03/2004 e na semana de 28/03 a 06/04/2004) até a formação completa da haste floral comercial. Na primeira etapa foram coletadas 4 hastes florais por tratamento em 5 tratamentos totalizando 60 flores por data de coleta. Na segunda etapa foram coletadas 13 hastes florais por tratamento em 4 tratamentos totalizando 52 hastes florais. Não houve diferença estatística entre os plásticos de ano de início de uso de 1998, 1999, 2002 e 2003 nas variáveis comprimento e diâmetro das hastes, diâmetro e comprimento dos botões florais, massa fresca e seca das pétalas. Para a análise dos parâmetros meteorológicos foram selecionados 12 vãos de estufas com plásticos de ano de uso 1998, 1999, 2002 e 2003, com três repetições cada. Foram estudadas as variáveis temperatura de bulbo seco, temperatura de bulbo úmido, umidade relativa, e intensidade luminosa, com dados coletados durante 35 dias, nos horários das 10, 11, 12, 13, 14, 15, e 16 horas. Para as condições meteorológicas estudadas não houve diferença estatística. Para a análise de envelhecimento do plástico os testes foram divididos em dois componentes distintos: teste de tensão e ruptura e a espectroscopia nas faixas do espectro solar entre 199 e 1500 nm. Para o teste de tensão e ruptura foram selecionadas amostras de plástico de início de uso 1998, 1999 e 2003 (sem uso) onde as variáveis analisadas foram tensão e deformação total. Também para estes itens não houve diferença estatística, sendo que os valores encontrados estão dentro da expectativa de envelhecimento esperado pela fábrica. Para o teste de espectroscopia os plásticos de ano de início de uso de 1998, 1999 e 2003 (sem uso) tiveram duas amostras por ano de uso, uma das quais foi lavada com detergente neutro e outra deixada no estado em que se encontrava. Conclui-se, portanto, que para as condições aqui estudadas não se recomenda a necessidade da troca do plástico de cobertura no período de tempo avaliado devido a não ter havido alterações substanciais na produção da cultura, como conseqüência tanto dos aspectos micrometeorológicos dentro das estufas como quanto aos aspectos funcionais de resistência e transmissividade do plástico / Abstract: The aim of this study is to evaluate a film, which is used as a covering for greenhouses, through the aspects of production and quality, meteorological and aging parameters of the plastic film, under the conditions imposed by the plastic covering with different years of usage. In order to evaluate the production and quality, it was selected 15 greenhouse voids with plastic coverings dating from 1998, 1999, 2002 and 2003 and also a control one with three repetitions each. Two production managements were used in this analyses: the commercial management used in the property (first stage) and a specific management (second stage) in which occurred a clear felling at the beginning of the experiment, in an area of 1 m2 done with the purpose of evaluating the development of the flower buds from the pruning to the commercial flower stalk. On the first stage it was done 4 collections along the experiment period (during the days 01/03/2004, 17/03/2004, 26/03/2004 and 05/04/2004). On the second stage it was evaluated the appearance of the floral buds of the new shoots in four dates (20/02/2004, 07/03/2004, 26/03/2004 and through the weeks of 28/03 to 06/04/2004) until the complete formation of the commercial flower stalks. On the first stage it was collected 4 flower stalks per treatment in 5 treatments making a total of 60 flowers per collecting day. On the second stage it was collected 13 flower stalks per treatment in 4 treatments making a total of 52 flower stalks. There was no statistic difference between the plastics, which began to be used in the years of 1998, 1999, 2002 and 2003, when related to the length and diameter of the stalks, diameter and length of the flower buds, dry and fresh mass of he petal. In order to analyze the meteorological patterns, it was selected 12 greenhouse voids hose plastics dated from of 1998, 1999, 2002 and 2003, each one with three repetitions. The ariables studied were the dry bulb temperature, the relative humidity and the luminous intensity, it datum collected during 35 days, during the period of 10:00, 11:00, 12:00 a.m. and 1:00, :00, 3:00, and 4:00 p.m. There was no statistic difference for the meteorological conditions studied. The tests were divided into two distinct components in order to analyze the plastic aging: ension and rupture tests and the spectroscopy on the areas of solar spectrums between 199 and 4000 nm. For the tension and rupture test it was selected plastic samples which began to be used n 1998, 1999 and 2003 (which has not been used yet) where the variables analyzed were, ension, total deformation. For these items there wasn?t a statistic difference as well, and the values found are in accordance with the aging expectancy expected by the factory. For the studied conditions is not recommended to change the plastic coverture into the evaluated time six years) due to not variations to crop production as consequence of plastic resistance and transmissivity / Doutorado / Agua e Solo / Doutor em Engenharia Agrícola

Orientador: Rumy Goto / Coorientador: Antonio Ribeiro da Cunha / Banca: João Domingos Rodrigues / Banca: Elizabeth Orika Ono / Banca: Rerison Catarino da Hora / Banca: Jerônimo Luiz Andriolo / Resumo: As condições ambientais são fundamentais para se produzir hortaliças com qualidade e com o uso do cultivo em ambiente protegido, passou-se a manejar o ambiente em favor da planta. Desde então, muitos produtores, no mundo todo, passaram a utilizar esta tecnologia, que possibilita a produção com maior qualidade e produtividade, o que tem sido atribuído em parte à maior quantidade de radiação solar difusa que ocorre neste ambiente. O polietileno de baixa densidade (PEBD), principal material utilizado na cobertura, transforma parte da radiação solar direta em difusa ao transmití-la para o interior do ambiente. Esta radiação é considerada mais eficiente. Visando-se explorar melhor este benefício, a indústria desenvolveu o plástico difusor de luz, que tem como principal característica transformar a radiação solar direta em difusa ao transmití-la para o interior do ambiente. No entanto, há poucos estudos com relação ao uso deste material, principalmente, quanto à transformação da radiação direta em radiação difusa e à densidade de plantas a ser utilizada. O objetivo deste trabalho foi avaliar algumas características fisiológicas e a produção de plantas de pimentão enxertado sob o plástico difusor de luz e em diferentes densidades de planta. O experimento foi conduzido na Fazenda Experimental de Pesquisa e Produção (FEPP) da UNESP/Botucatu em São Manuel - SP. Plantas de pimentão do híbrido Melina foram enxertadas sobre o porta-enxerto AF-8253 e foram transplantadas em três ambientes (PEBD comum (PEBDc), PEBD difusor de luz (PEBDd) e a campo) e três espaçamentos de plantas (1,50 m entre linhas e 20; 35 e 50 cm entre plantas). Os valores de transmissividade à radiação solar ... / Abstract: Environmental conditions are fundamental to produce vegetables with quality. The use of protected cultivation, environment management has favored plants. Since then many growers worldwide have been utilizing this technology that enable production with better quality and yield which is partly due to the increase in diffuse solar radiation inside this environment. Low density polyethylene (LDPE), the main material utilized as cover, makes part of the direct solar radiation diffuse within the protected environment. This radiation is considered more efficient. Aiming to explore this benefit better, diffuse light plastic has been developed to transform great part of direct solar radiation into diffuse within a greenhouse. However, there are few studies related the use of this material, mainly regarding the transformation of direct solar radiation into diffuse, and regarding plant densities. The aim of this study was to evaluate some physiological characteristics of grafted sweet pepper plants inside light-diffuser plastic at different plant densities. The experiment was carried out at "Fazenda Experimental São Manuel" of FCA/UNESP in Botucatu-SP. Sweet pepper plants of Melina hybrid grafted on AF-8253 rootstock were utilized. Treatments consisted of three environments: one covered with common LDPE, another covered with light-diffuser LDPE, and the third one was an uncovered field production, and three spacings (150 cm between rows, and 20, 35 and 50 cm between plants). Values of global solar radiation transmissibility were 56.0 and 73.3% in light-diffuser LDPE and common LDPE, respectively. There was a small reduction in the transmissibility of photosynthetically active radiation compared to global radiation ... / Doutor

No description available.