Avaliou-se a bioatividade de derivados do nim (Azadirachta indica A. Juss.) como componente de isca para adultos e como regulador de crescimento de Ceratitis capitata (Wied.) e Anastrepha fraterculus (Wied.), determinando-se, ainda, o efeito de concentrações subletais de extratos de nim e o efeito deterrente de oviposição do extrato metanólico de folhas sobre C. capitata. Utilizando o extrato aquoso de amêndoas de nim, estimou-se a CL50 para adultos e imaturos, cujos valores foram 7.522 e 1.368 ppm para os adultos e 13.028 e 9.390 ppm para os imaturos de A. fraterculus e C. capitata, respectivamente. Subsequentemente, o óleo de amêndoas, os extratos de folhas, de ramos e de amêndoas de nim em diferentes solventes (água, metanol, diclorometano e hexano) foram comparados com base nas CL50 obtidas para adultos e para imaturos. Posteriormente, foram estimadas concentrações subletais (CL15 = 39 ppm, CL30 = 225 ppm e CL45 = 888 ppm) do extrato aquoso de amêndoas para adultos de C. capitata e avaliouse nessas concentrações o efeito do extrato aquoso de amêndoas, de folhas em metanol e de ramos em diclorometano sobre a reprodução e a longevidade dessa espécie. A deterrência de oviposição do extrato metanólico de folhas de nim em diferentes concentrações (10.000, 18.000, 32.000 e 56.000 ppm) para C. capitata foi avaliada tratando bagas de uva, que foram expostas às fêmeas com chance e sem chance de escolha. Verificou-se que os derivados do nim na concentração de até 7.522 e 1.368 ppm não afetaram os adultos de A. fraterculus e C. capitata, respectivamente. Já para a fase imatura, os extratos de amêndoas e de ramos em diclorometano na concentração de 13.028 ppm causaram mortalidade de A. fraterculus e na concentração de 9.390 ppm o extrato de amêndoas em metanol e em diclorometano causaram mortalidade de C. capitata. Houve redução da fecundidade total e da fertilidade no 8º dia quando os insetos foram alimentados com extrato de ramos em diclorometano a 888 ppm. A longevidade de machos e fêmeas e o período de pré-oviposição não foram afetados pelos tratamentos. O extrato de folhas em metanol provocou deterrência de oviposição para C. capitata em situação de chance de escolha, porém, em confinamento, o referido extrato não afetou o comportamento dessa espécie. A experiência recente de C. capitata não alterou a sua resposta em relação a bagas de uva tratadas. A atividade biológica dos derivados do nim em relação às moscas-das-frutas é discutida. / The bioactivity of neem (Azadirachta indica A. Juss.) as adult bait and as larval growth regulator for Ceratitis capitata (Wied.) and Anastrepha fraterculus (Wied.) was evaluated. Besides, the effect of sublethal concentrations of neem extracts and the oviposition deterrency of the methanolic extract from leaves on C. capitata was evaluated. The estimated LC50 of aqueous extract from seed kernels were 7,522 and 1,368 ppm for adults and 13,028 and 9,390 ppm for immatures of A. fraterculus and C. capitata, respectively. In addition, the oil from seed kernels and the extracts from leaves, branches and seed kernels in different solvents (water, methanol, dichloromethane and hexane) were compared based on the LC50 obtained for adults and immatures. After that, sublethal concentrations from aqueous extract from neem seed kernels for C. capitata adults were estimated (LC15 = 39 ppm, LC30 = 225 ppm and LC45 = 888 ppm) and the effects of such concentrations on the reproduction and logenvity of this species were also accessed. Oviposition deterrency of C. capitata to grapes treated with leaf methanolic extract at different concentrations (10,000; 18,000; 32,000 and 56,000 ppm) was evaluated in free-choice or no-choice test. It was verified that the neem extracts on the concentrations up to 7,522 and to 1,368 ppm did not affect the adults of A. fraterculus and C. capitata, respectively. On the other hand, the extract from seed kernels and branches in dichloromethane at 13,028 ppm provoked mortality in A. fraterculus larvae and the seed kernel extract in methanol and dichloromethane at 9,390 ppm provoked high mortality in C. capitata larvae. The total fecundity was reduced significantly and the fertility decreased on the 8th day when the insects were fed on branch extract in dichloromethane at 888 ppm. The longevity of males and females and the pre-oviposition period were not affected by treatments. The leaf extract in methanol provoked oviposition deterrency for C. capitata in free-choice test, but did not affect its behavior in no-choice test. The C. capitatas early experience did not affect its answer to the grapes treated in free-choice and no-choice situations. The biological activity of the neem extracts to fruit flies is discussed.

Com o objetivo de estudar o comportamento fenológico, morfológico e produtivo de cultivares de algodoeiro com diferentes arquiteturas de plantas em diferentes espaçamentos, através do manejo com regulador de crescimento, foi realizado o presente trabalho, na área experimental da ESALQ/USP, no município de Piracicaba, Estado de São Paulo, no ano agrícola de 2000/01. O delineamento experimental utilizado foi o de blocos ao acaso com parcelas sub-subdivididas e 4 repetições. As parcelas constituíram-se dos espaçamentos de 0,76 e 1,01 m, as subparcelas das três cultivares (IAC 23, DeltaOpal e CD 401) e as sub-subparcelas em presença ou ausência de regulador de crescimento. Em seis plantas marcadas de cada parcela foram analisados os seguintes parâmetros: acompanhamento das fases fenológicas (emergência, aparecimento do primeiro botão floral, antese da primeira flor e abertura do primeiro capulho) e caracteres agronômicos de campo (altura de planta, diâmetro do caule, número de ramos vegetativos e frutíferos, conformação da planta, número de capulhos por planta e altura de inserção do primeiro ramo frutífero). Na área útil de cada parcela foi determinada, a produção de algodão em caroço por hectare e a precocidade de colheita. Em amostras de 20 capulhos tomadas aleatoriamente em cada parcela foram realizadas as análises dos caracteres agronômicos de laboratório (massa de 100 sementes, porcentagem de fibras e massa média de um capulho) e das características tecnológicas da fibra (comprimento, uniformidade de comprimento, maturidade, tenacidade e índice micronaire). Os resultados obtidos permitem concluir que não houve interações significativas para as cultivares x espaçamentos x regulador de crescimento, para a produção de algodão em caroço, precocidade de colheita, caracteres agronômicos de laboratório e características tecnológicas das fibras, com exceção da tenacidade. Desta forma, as cultivares avaliadas, independente da arquitetura da planta, apresentaram capacidade de ajustar-se às variações dos espaçamentos testados e aplicação de regulador de crescimento com relação a estas características. Os caracteres agronômicos de campo como: a altura das plantas e o diâmetro de caule, de modo geral, apresentaram médias reduzidas com a redução do espaçamento e aplicação do regulador de crescimento, para as cultivares de desenvolvimento mais vigoroso (IAC 23 e DeltaOpal), não influenciando, porém, a cultivar de plantas morfologicamente mais compactas (CD 401). / The purpose of this work was to study the phenological, morphological and productive behavior of cotton cultivars presenting different plant shapes under different spacing layouts managed with the use of plant growth regulator. The experiment was established in the experimental field of ESALQ/USP, Piracicaba, Sao Paulo, during the 2000/01 growing season and was arranged in a randomized block experimental design with subdivided plots and 4 replications. The plots represented spacing layouts of 0.76 and 1.01 m, subplots consisted of the IAC 23, DeltaOpal and CD 401 cultivars, while the sub-subplots were characterized by the use or absence of growth regulator. Six plants per plot were labeled and analyzed for the phenological phases (emergence, appearance of the first flower bud, anthesis of the first flower, opening of the first cotton boll) and field agronomical characteristics (plant height, stem diameter, number of vegetative and fruit branches, plant shape, number of cotton boll per plant and insertion height of the first fruit branch). The harvest early and raw cotton yield per hectare were determined considering the effective plot area. The agronomical lab characteristics (mass of 100 seeds, fiber percentage and cotton boll mass), as well as the fiber technological characteristics (length, length uniformity, maturity, strength, and micronaire) were analyzed using a sample of 20 bolls taken at random. Based on the results obtained, it can be concluded that there were no significant interactions among cultivars x spacing x growth regulator, as to cotton yield, harvest early, agronomical lab characteristics and fiber technological characteristics, except for stremgth. The analyzed cultivars, regardless of the plant shape, showed good adaptation to the variation in spacing layouts, as well as to the application of growth regulator, considering the analyzed characteristics. The field agronomical characteristics, such as plant height and stem diameter, generally decreased with the reduction in spacing and with the application of growth regulator, considering the most vigorous cultivars (IAC 23 and DeltaOpal). On the other hand, the cultivar presenting a more compact plant (CD 401) pattern was not influenced by spacing or use of growth regulator.

O emprego de reguladores vegetais como maturadores da cana-de-açúcar tem sido uma prática bem utilizada, em virtude da necessidade de antecipação da colheita e da otimização do planejamento agrícola. Contudo, com a freqüente disponibilidade de genótipos de cana-de-açúcar pelos programas de melhoramento, pouca informação se tem das interações entre novos genótipos e produtos sobre a qualidade tecnológica. Este estudo objetivou determinar a resposta de sete genótipos de cana-de-açúcar à aplicação de dois reguladores vegetais quanto à influência na qualidade da matéria prima. O ensaio foi instalado em março de 2004 e conduzido na APTA Regional Centro-Oeste, Jaú (SP). O delineamento experimental foi o de blocos casualizados, em parcelas sub-divididas, com quatro repetições, constituído pela combinação dos genótipos IAC87-3396, IAC87-3410, IAC89-3124, IAC91-2195, IAC91-5155, PO88-62 e SP80-1842, e de três manejos de condução da maturação sulfometuron metil, 20 g p. c. ha-1; etefon, 2,0 l p. c. ha-1 e testemunha. A qualidade tecnológica foi determinada através dos atributos Brix no caldo, pol no caldo, pureza do caldo, fibra da cana, pol na cana, açúcares redutores no caldo, açúcares redutores na cana e açúcar total recuperável (ATR) aos 0, 21, 42, 63, 84, 105 e 126 dias após a aplicação (DAA), além dos atributos florescimento, "isoporização", produtividade de colmos e de açúcar aos 126 DAA. Observou-se que, para a maioria dos genótipos, o emprego dos maturadores antecipou a colheita em 21 dias em relação à testemunha, sendo o etefon indicado para colheita entre 42 e 84 DAA, e o sulfometuron metil para o período entre 105 e 126 DAA. O IAC91-5155 não respondeu aos maturadores, o PO88-62 apresentou melhor resposta ao sulfometuron metil, e os demais genótipos ao uso de etefon, quanto à qualidade tecnológica. Os dois produtos, etefon e sulfometuron metil, controlaram o florescimento. Os genótipos IAC91-5155 e PO88-62, apesar de não florescidos, apresentaram "isoporização". Para a maioria dos genótipos a aplicação dos maturadores não afetou a produtividade de colmos, exceto para o sulfometuron metil que reduziu a do genótipo SP80-1842, e para etefon que aumentou a do IAC91-2195. O sulfometuron metil e o etefon aumentaram a produtividade de açúcar do genótipo IAC89- 3124. O IAC91-2195 apresentou produtividade de açúcar maior com a aplicação de etefon. A produtividade de açúcar foi menor no SP80-1842 com o emprego de sulfometuron metil. / Use of plant growth regulators as sugarcane ripeners has been a practice well used, because of the need of early harvest and the agricultural planning optimization of the crop. However, with the frequent release of genotypes by breeding programs, little information is available about of the interactions among new genotypes and products over the technological quality. This study aimed to determine the response of seven sugarcane genotypes to the application of two ripeners in the raw material quality. The experiment was installed in march 2004 and carried out in the APTA Regional Center West, Jaú (SP). The experimental design was the randomized complete blocks, in split-plot, with four repetitions, constituted by the genotypes IAC87-3396, IAC87-3410, IAC89-3124, IAC91- 2195, IAC91-5155, PO88-62 and SP80-1842, and by three ripening manegement sulfometuron methyl, 20 g p. c. ha-1; ethephon, 2,0 l p.c. ha-1 and control. The technological attributes evaluated were Brix in the juice, pol in the juice, purity of the juice, fiber of the cane, juice reducing sugars, stalks reducing sugars and recoverable total sugars (ATR) to 0, 21, 42, 63, 84, 105 and 126 days after the application (DAA) besides flowering, pith, productivity of stalks and sugar attributes to 126 DAA. It was observed that for the most of the genotypes the use of ripeners antecipated the harvest in 21 days in relation to control, being ethephon recomendable for harvest between 42 and 84 DAA, and sulfometuron methyl for the period between 105 and 126 DAA. The genotype IAC91-5155 didn't answer to the ripeners, PO88-62 presented better answer to sulfometuron methyl and the others genotypes to ethephon to technological quality. Both products, ethephon and sulfomethuron methyl, controlled the flowering. The genotypes IAC91-5155 and PO88-62, in spite of no flowering, presented pith. For most of the genotypes the application of the ripeners didn't affect the productivity of stalks, except to sulfomethuron methyl that reduced it in SP80- 1842, and to ethephon that increased it in IAC91-2195. Sulfomethuron methyl and ethephon increased the productivity of sugar of the genotype IAC89-3124. IAC91-2195 presented bigger sugar productivity with ethephon application. The productivity of sugar was smaller in SP80-1842 with sulfomethuron methyl use.

O avanço da cultura do maracujazeiro no país impulsionado pela agroindústria de suco e a crescente demanda de fruta fresca, acarretou o surgimento de problemas, principalmente de ordem fitossanitária, doenças causadas por fungos, bactérias e vírus. A espécie Passiflora cincinnata Mast. por apresentar resistência à doença da parte aérea causada pela ba ctéria Xanthomonas campestris f. sp. passiflorae e, potencial para a comercialização constitui um genótipo de interesse em programas de melhoramento. Visto que a cultura de tecidos tem sido ferramenta importante nesses programas, o presente projeto visa o estudo aspectos anatômicos e fisiológicos da organogênese in vitro dessa espécie. Os explantes utilizados: segmentos radiculares, discos foliares e a própria plântula, obtidos da germinação de sementes in vitro, foram inoculados em meio contendo diferentes concentrações de 6-BA (6-benziladenina) e acrescido de 5% de água de coco, a fim de estabelecer os protocolos de regeneração de plantas in vitro. A concentração de 0,5 mg.L -1 de 6-BA foi a mais adequada para os três explantes, porém, o tempo e a via (direta/indireta) de formação da gema diferiu para cada tipo de explante. Os eventos histológicos que levaram a formação de um novo órgão, via meristemóides (centros meristemáticos) foram descritos. Nos discos foliares a origem foi indireta, com formação de calo a partir das células subepidérmicas das camadas de parênquima clorofiliano. Nos segmentos de raiz e nas raízes das plântulas, a organogênese direta apresentou duas origens, a partir do periciclo, nas raízes com início da estrutura secundária, e a partir do câmbio vascular, nas raízes com estrutura secundária já estabelecida. Também nos segmentos de raiz observou-se a via indireta, esta a partir da proliferação do periciclo. / The progress of passionfruit culture in the country stimulated by the juice agroindustry and due to an increased demand of fresh fruit have brought phytosanitary problems, such as, diseases caused by fungis, bacterium and virus. The Passiflora cincinnata Mast. a resistant specie to Xanthomonas campestris f. sp. Passiflora bacterium shows a potential for commercialization creating an interest genotype in breedings programs. Whereas the tissue culture has been an important instrument for those programs, object of this program is to study the anatomical and physiologycal aspects of organogenesis "in vitro" of this specie. The explants used were: root segments, leaf discs and the seedlings obtained from germination of seeds "in vitro". They were placed in different solutions of 6-BA (benzyladenine) and with 5% of coconut water, in order to establish protocol for plant regeneration "in vitro". The concentration of 0,5 mg.L- 1 of 6-BA was the most adequate for all three explants, but the time and nourishement source (direct/indirect) to the shoots formation differed to each kind of explants. The histological events had lead the formation of a new organ, by meristemoids (meristematic centers) were described. In the leaf discs the indirect origin, was observed in which callus were formatted by the layer of chlorophyll parenchyma subepidermis cells. In the root segments and in the root plantets, the direct organogenesis showed two origins (source), from the pericycle, on the roots that starts at the secondary structure and from vascular cambium, on the roots that had already been established secondary structure. Also the root segments was seen by the indirect way, which callus were formatted by the pericycle proliferation.

Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2017-03-28T13:22:07Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_igor_tonin.pdf: 373470 bytes, checksum: a238602334cacca2e05e75ae1da2e45a (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-04-05T17:37:40Z (GMT) No. of bitstreams: 2 dissertacao_igor_tonin.pdf: 373470 bytes, checksum: a238602334cacca2e05e75ae1da2e45a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-04-05T17:38:40Z (GMT) No. of bitstreams: 2 dissertacao_igor_tonin.pdf: 373470 bytes, checksum: a238602334cacca2e05e75ae1da2e45a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-04-05T17:38:50Z (GMT). No. of bitstreams: 2 dissertacao_igor_tonin.pdf: 373470 bytes, checksum: a238602334cacca2e05e75ae1da2e45a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-09-08 / Sem bolsa / O trigo (Triticum aestivum L.) é uma cultura de destaque econômico e um dos cereais de inverno mais cultivados no sul do Brasil. Entretanto, suas sementes apresentam dormência, sendo um fator limitante em programas de melhoramento genético, quando se deseja rápida germinação pós-colheita, necessitando dessa forma, viabilizar tecnologias para potencializar a germinação. A pesquisa teve como objetivo avaliar a eficácia de doses de ácido giberélico na superação de dormência de sementes de trigo. As sementes de trigo da cultivar TBIO Toruk foram tratadas com inseticida Cropstar imidacloprid+thiodicarb 600 SC), fungicida Spectro (difenoconazol 150 SC) seguido de adição na calda do TS de GA3 nas respectivas dosagens. Os tratamentos empregados consistiram em doses de ácido giberélico, sendo: Pro-Gibb® (50 mg Kg-1 de GA3); Pro-Gibb® (100 mg Kg-1 de GA3); Pro-Gibb® (150 mg Kg-1 de GA3); Pro-Gibb® (200 mg Kg-1 de GA3); Pro-Gibb® (250 mg Kg-1 de GA3); Pro-Gibb® (300 mg Kg-1 de GA3) e testemunha (semente sem tratamento). Para avaliar a eficácia do GA3 as variáveis analisadas foram germinação, primeira contagem da germinação, velocidade de germinação, índice e coeficiente de velocidade de germinação. Os resultados obtidos permitem concluir que o ácido giberélico influenciou de forma positiva na superação da dormência de sementes de trigo, onde foi constatado maior porcentagem de germinação e vigor. A dose de ácido giberélico de 50 mg Kg-1, propiciou maior porcentagem de germinação (91 %), com incremento de 35 % na germinação de sementes de trigo quando comparado com sementes não tratadas. Por outro lado, constatou-se que doses de ácido giberélico, acima de 250 mg Kg-1, não são recomendadas para superação de dormência de sementes de trigo. / Wheat (Triticum aestivum L.) is a crop that has highlight of economic and one of the most important winter cereals grown in southern Brazil. However, the seeds present dormancy, limiting factor in breeding programs, considering that is necessary germination immediately after the harvest, requiring viable technologies to enhance germination. The research aimed to evaluate the effectiveness of gibberellic acid doses in overcoming wheat seed dormancy, It was used wheat seeds cultivar TBIO Toruk, Were treated with Cropstar insecticide (imidacloprid + thiodicarb 600 SC), Spectro fungicide (difenoconazole 150 SC) followed by the addition of the TS with GA3 in the dosis evaluated. The treatments consisted in the use of gibberellic acid doses, as follows: Pro-Gibb® (50 mg Kg-1 GA3); Pro-Gibb® (100 mg Kg-1 GA3); Pro- Gibb® (150 mg Kg-1 GA3); Pro-Gibb® (200 mg Kg-1 GA3); Pro-Gibb® (250 mg Kg-1 GA3); Pro-Gibb® (300 mg Kg-1 GA3) and Witness without treatment. To evaluate the effectiveness of GA3 it was analyzed the variables: germination, first germination count, germination rate, index and coefficient of germination speed. The obtained results allow us to conclude that gibberellic acid positively influenced the physiological quality of wheat seeds, where was found greater percentage of germination and vigor. A gibberellic acid dose of 50 mg Kg-1, show greater germination percentage (91 %), an increase of 35 % in wheat seeds germination when compared to untreated seeds. Gibberellic acid doses above 250 mg Kg-1, are not recommended for overcoming wheat seed dormancy.

A coloração e o tamanho são fatores determinantes na qualidade dos frutos de caroço. Por este motivo, foram utilizadas duas práticas culturais, anelamento de ramos e aplicação de regulador vegetal, com o objetivo de melhorar a qualidade de frutos de pessegueiro na cultivar de meia estação Biuti. Os tratamentos foram realizados na fase de endurecimento do caroço e utilizou-se 0; 12,5; 25 e 50 mg L -1 do regulador vegetal 2,4-DP, com e sem anelamento de ramos. Com base nos resultados obtidos, pôde-se concluir que os tratamentos não se mostraram eficazes quanto à antecipação da colheita. Ocorreu um aumento no peso médio de frutos com até 100 gramas, na primeira colheita, nas plantas tratadas apenas com anelamento de ramos. Em relação aos frutos com mais de 105 gramas, ocorreu uma diminuição do peso médio nas plantas aneladas, na primeira colheita, à medida que se aumentavam as concentrações do regulador vegetal. Além disso, não houve diferenças significativas quanto ao pH do suco, acidez total e teor de sólidos solúveis totais em nenhum dos tratamentos avaliados. No entanto, os frutos das plantas tratadas apresentaram coloração intensificada da casca em relação aos de plantas não tratadas. / Coloring and size are decisive factors of pit fruit quality. For this reason, it was used two cultural practices, the ringing branches and the growth regulator application, to enhance fruit quality of Biuti, a middle season peach cultivar. The treatments were done at pit hardening and it was used 0; 12,5; 25 and 50 mg L -1 of 2,4-DP growth regulator, with and without the ringing branches. According to the results, it was concluded that treatments were not efficient to bring harvest forward. It had an increase at medium fruit weight until 100 grains, at first harvest, only in the peach trees that were ringed. It had a decrease in medium fruit weight over 105 grains in ringed trees, at first harvest, by the way in witch growth regulator concentrations were increased. There were not significant differences in pH fruit juice, total acidity and total soluble solid concentration at any treatment. However, there was an enhancement in fruit peel coloring at treated trees.

Orientador: Ciro Antonio Rosolem / Banca: João Domingues Rodrigues / Banca: Luiz Henrique Carvalho / Resumo: O experimento foi conduzido de janeiro a abril de 2007 sob condições de casa de vegetação. O objetivo foi avaliar o comportamento de cultivares de algodão submetidas a doses de cloreto de mepiquat e, ainda, verificar se a resposta está ligada ao ciclo ou arquitetura da cultivar. Os tratamentos foram constituídos de seis cultivares com comportamento de crescimento e diferentes ciclos produtivos (FiberMax 966, FiberMax 977, DeltaPenta, DeltaOpal, FMT 501 e FMT 701), bem como, a utilização de quatro doses do regulador vegetal a base de cloreto de mepiquat (PIX®): 7,5; 15,0 e 22,5 g ha-1 de i.a e a testemunha sem aplicação do produto. Foram utilizados vasos de 12 litros de capacidade, sendo cultivadas duas plantas por vaso. O delineamento experimental utilizado foi em blocos casualizados com quatro repetições em esquema fatorial 4 doses x 6 cultivares. As avaliações constituíram da: altura de plantas, número de ramos reprodutivos, massa de matéria fresca e massa de matéria seca, retenção de estruturas reprodutivas e área foliar. Para cada cultivar, foi calculada a relação entre taxa de crescimento em altura e concentração do regulador. Os resultados mostraram que o crescimento das plantas de algodoeiro em altura é diminuído com a aplicação foliar de cloreto de mepiquat, sendo maior a redução de altura, quanto maior a quantidade de regulador aplicada. Existe diferença entre as cultivares estudadas quanto à sensibilidade ao regulador, de modo que as mais precoces são mais sensíveis. Para a mesma dose aplicada, a concentração de regulador vegetal na planta é diferente, pois a quantidade de produto depositada na folha de cada cultivar é também diferente. O regulador não afetou a taxa de assimilação de CO2 das cultivares de algodão estudadas. / Abstract: The experiment was conducted between January and April 2007 under greenhouse conditions. The objective to evaluate the behavior of cotton cultivars submitted to the doses of Mepiquat Chloride, and also to find if the answer is linked to the cycle or architecture of cultivar. The treatments were constituted of six cultivars of different behaviour about its growth and cycle (FiberMax 966, FiberMax 977, DeltaPenta, DeltaOpal, FMT 501 e FMT 701); and four doses of the plant growth regulator, mepiquat chloride (PIX®): 7,5, 15,0, 22,5 g ha-1 and a control (0,0 g ha-1). Plots of 12 liters of capacity were used with two plants per plot. The experimental design used was the completely randomized with four replications in outline factorial 4 doses x 6 cultivars. The parameters analyzed were: height of plants, number of reproductive branches, weight of dry matter, retention of reproductive structures, and leaf area. Also, it was calculated for each cultivar, the relationship among growth rate in height and concentration of the regulator. The results showed that the growth of cotton plants in height is reduced by application of mepiquat chloride, and the height reduction is larger, as larger the amount of plant growth regulator applied. There is difference among the cultivars studied for sensitivity to the plant growth regulator, so that the earliest cultivars are more sensitive. In the same applied dose, the concentration of plant growth regulator in the plant is different because the amount of product deposited on the left of each cultivar is different too. The mepiquat chloride didn't affect the assimilation rate of CO2 to the cotton cultivars studied. / Mestre

Genetically modified cotton (Gossypium hirsutum L.) acreage has increased dramatically over the last six years. Reports of variable results in fiber quality and yield have arisen in these cultivars. Some changes in production practices have occurred coincident with the introduction of transgenic technology, such as reduced use of broad-spectrum insecticides, including organophosphates (OP) that could potentially influence the growth and yield of cotton. One factor that might affect these parameters is the difference in the amount of foliarly-applied phosphorus (P) between an OP and non-phosphate (NP) insecticide regime. Therefore, a study was conducted to investigate selected growth characteristics, yield, and fiber quality of genetically modified and conventional cotton as influenced by OP and foliar phosphorus (FP) applications. A four replication strip-plot experimental design was utilized with cultivar serving as the whole plot and insecticide regime as the sub-plot. Three cultivars of the same recurrent parent (ST4892BR, ST4793R, and ST474) were planted in 2001 and 2002 under irrigated conditions in Burleson County, TX on a Weswood silty clay loam (fine-silty, mixed, thermic Fluventic Ustochrept). The insecticide regime consisted of NP, NP+FP, and OP treatments. The FP was applied at P2O5 weight equivalent to the P component in the concurrent OP application. ST4892BR had greater lint yield than ST4793R and ST474. The yield increase can be explained through plant mapping analysis which showed ST4892BR producing larger bolls and greater boll numbers. In addition, evaluation of fruiting distribution showed ST4892BR contained more lint on sympodial branches 6 through 10. The insecticide regime effect on lint yield resulted in higher yield (P=0.08) for the NP+FP regime. Examination of yield components revealed NP+FP increased second position bolls, predominantly at sympodial branches 6 through 10. Leaf tissue analysis revealed increased levels of P for the OP and NP+FP over that of the NP insecticide regime, which indicates a potential for plants to acquire P from OP insecticides. Furthermore, the considerable yield response to small amounts of FP is not clearly understood. While conclusive evidence exists regarding cultivar yield differences, this study does not provide sufficient evidence to conclude that OP insecticides influence growth, yield, or fiber quality characteristics of these cotton cultivars.

Genetically modified cotton (Gossypium hirsutum L.) acreage has increased dramatically over the last six years. Reports of variable results in fiber quality and yield have arisen in these cultivars. Some changes in production practices have occurred coincident with the introduction of transgenic technology, such as reduced use of broad-spectrum insecticides, including organophosphates (OP) that could potentially influence the growth and yield of cotton. One factor that might affect these parameters is the difference in the amount of foliarly-applied phosphorus (P) between an OP and non-phosphate (NP) insecticide regime. Therefore, a study was conducted to investigate selected growth characteristics, yield, and fiber quality of genetically modified and conventional cotton as influenced by OP and foliar phosphorus (FP) applications. A four replication strip-plot experimental design was utilized with cultivar serving as the whole plot and insecticide regime as the sub-plot. Three cultivars of the same recurrent parent (ST4892BR, ST4793R, and ST474) were planted in 2001 and 2002 under irrigated conditions in Burleson County, TX on a Weswood silty clay loam (fine-silty, mixed, thermic Fluventic Ustochrept). The insecticide regime consisted of NP, NP+FP, and OP treatments. The FP was applied at P2O5 weight equivalent to the P component in the concurrent OP application. ST4892BR had greater lint yield than ST4793R and ST474. The yield increase can be explained through plant mapping analysis which showed ST4892BR producing larger bolls and greater boll numbers. In addition, evaluation of fruiting distribution showed ST4892BR contained more lint on sympodial branches 6 through 10. The insecticide regime effect on lint yield resulted in higher yield (P=0.08) for the NP+FP regime. Examination of yield components revealed NP+FP increased second position bolls, predominantly at sympodial branches 6 through 10. Leaf tissue analysis revealed increased levels of P for the OP and NP+FP over that of the NP insecticide regime, which indicates a potential for plants to acquire P from OP insecticides. Furthermore, the considerable yield response to small amounts of FP is not clearly understood. While conclusive evidence exists regarding cultivar yield differences, this study does not provide sufficient evidence to conclude that OP insecticides influence growth, yield, or fiber quality characteristics of these cotton cultivars.

Linseed flax studies in vitro were carried out at the Laboratory of Genetic – Biotechnological, Department of Crop Science and Animal Husbandry of Lithuanian University of Agriculture in 2002-2005, photomorphogenetic processes were investigated at the Laboratory of Plant Physiology of the Lithuanian Institute of Horticulture in 2004-2005. Optimal conditions for the dedifferentiation of linseed flax stem segments and hypocotyls cells and those of secondary differentiation in vitro were ascertained. Light technology of a solid body was used for investigation and an optimal combination of light parameters has been selected, promoting photomorphogenesis in vitro. Factors determining androgenesis and gynogenesis processes in vitro were evaluated and potential androgenic and gynogenic genotypes for the development of initial selection material were selected.