Herbaceous peonies (Paeonia lactiflora Pall.) are common perennials used both in gardens and the landscape as well as for cut flowers. Peonies require a chilling period to break dormancy but not for flower bud differentiation. For all studies discussed in this dissertation, two peony cultivars, Sarah Bernhardt and Inspecteur Lavergne, small (3–5 eye) crowns from Holland were potted in 3.8-L pots in mid-November of 2017 and 2018. Our overall objective was to determine if we could manipulate chilling time, along with application of gibberellic acid (GA3) and growth retardants, to produce marketable containerized peonies from a small crown in a single season (November to May). We evaluated chilling, GA3 and a growth retardant (uniconazole; UNZ) under controlled chilling and greenhouse forcing conditions. All potted plants were held outdoors at Battlefield Farms (Rapidan, VA, 38˚ N) for 4 weeks [in 2017, 400 chilling units (CU) according to Fulton Chilling Model] or in a 10°C cooler for 5.5 weeks (in 2018, 400 CU) to root, then placed in a 5°C cooler for 3, 4 or 5 weeks (total 752, 869 or 986 CU). GA3 was applied as a 0 or 100 mg·L-1 drench at 250 ml/pot after the plants were moved into the Virginia Tech greenhouse (Blacksburg, VA, 37˚ N) for forcing. Uniconazole drenches were applied to each cultivar under each chilling treatment at 355 ml/pot at 0, 15, or 20 mg·L-1 at 7 days after the GA3 drench applications. Three weeks chilling at 5°C (752 CU total) provided sufficient chilling for 'Sarah Bernhardt' and 'Inspecteur Lavergne'. Application of GA3 reduced production time and resulted in a greater number of shoots, and, in three of the four studies, increased the number of flowering shoots in three of the four studies. Substrate drench application of 15 mg·L-1 UNZ prior to spring emergence reduced plant width moderately resulting in improved compactness of both cultivars. We evaluated the effects of plant growth retardants applied with different methods at different stages of production on the growth and development of containerized peony under nursery conditions. All potted plants were placed in an unheated coldframe at the Virginia Tech Urban Horticulture Center (Blacksburg, VA, 37˚ N) for one month after potting to promote rooting and then were moved outdoors to a gravel pad to receive natural chilling from November to February. In 2017–18, substrate drenches of UNZ at 0, 15, 30 or 45 mg·L-1 or paclobutrazol (PBZ) at 0, 30, 60 or 90 mg·L-1 at 237 mL/pot were applied about 4 weeks after potting for both cultivars in mid-December 2017. In 2018–19, fall drenches of uniconazole at 0, 15, 30 or 45 mg·L-1 at 237 mL/pot were applied about 4 weeks after potting in mid-December 2018, or spring sprenches of uniconazole were applied at 0, 15, 30 or 45 mg·L-1 at 840 mL·m-2 in March 2019 after 50% shoot emergence for each cultivar. Plant growth retardant applications had little effect on plant growth of either cultivar, but treated plants were of a darker green color compared to the control plants. In addition, higher rates of uniconazole applied as a fall drench increased the number of flowering shoots of both cultivars and the percentage of plants flowering for 'Sarah Bernhardt' in the second season of the study where plants were more protected from spring freezes. Fall paclobutrazol drenches or spring uniconazole sprenches had little effect on flowering. To determine the best timing for spring GA3 applications under nursery conditions, we applied three models based on natural chilling accumulation. The models were a modified Fulton Chilling Model (FCM) for herbaceous peonies, Blackberry Chilling Model 5 (BCM5) for blackberry, or a visual development model (VDM) which was 10% of plants showing shoot emergence in the spring. We choose 1,000 CU for the first two chilling models as the chilling required to break dormancy and promote normal plant growth and flowering. All plants were held in an unheated coldframe at the Virginia Tech Urban Horticulture Center for one month after potting to promote rooting, then were moved outdoors to a gravel pad to receive natural chilling over the winter months. Drenches of 0 or 100 mg·L-1 GA3 were applied at 250 mL/pot to each cultivar under each chilling model when the specific conditions were met. Due to greater winter injury in the 2017–18 season, results varied by year. In the 2017–18 season, GA3 applied according to BCM5 reduce days to emergence for both cultivars and reduce the plant width of 'Inspecteur Lavergne', and later application according to BCM5 and VDM reduced plant length and diameter of 'Sarah Bernhardt'. Reductions in plant size may have been due to greater winter injury due to the earlier emergence of GA3 treated plants. In the 2018–19 season, earlier GA3 drench applications tended to reduce days to emergence for both cultivars and the FCM application reduced days to bud for 'Inspecteur Lavergne', but GA3 drench applications had no effect on plant size. GA3 can be applied after chilling (1,000 CU) using a suitable chilling model such as FCM for peonies, or BCM5, or VDM, but GA3 had little effect on plant development under nursery conditions. We also evaluated GA3 effects on peony bud differentiation and development during controlled chilling and early forcing, as well as effects on growth and flowering. All potted plants were held in a 10°C cooler for 5.5 weeks (400 CU) to root, then placed in a 5°C cooler for 4 weeks (total 869 CU). GA3 was applied at 0 or 100 mg·L-1 pre-chilling or post-chilling as a 250 ml/pot drench. Bud differentiation and development of excised buds were evaluated using a stereomicroscope at potting, after rooting (before chilling), after 1, 2, 3 or 4 weeks of chilling, and at 5, 10 or 15 days after the beginning of forcing. All buds were removed from the sample plants, measured for bud length and diameter, and dissected under a stereomicroscope to assess differentiation stages. Root dry weights and crown dry weights were also determined after rooting, after chilling, and at 15 days of forcing. Ten plants of each treatment were grown in the Virginia Tech greenhouse after chilling until flowering. GA3 applications did not advance the bud development stage because most of buds were already in the reproductive stages before dormancy, but GA3 enhanced bud elongation during chilling and the early forcing period. Our findings suggest that GA3 applications can reduce the time to emergence and flowering, as well as increase the numbers of shoots and flowering shoots. GA3 applied right after rooting in, prior to the chilling period, or before greenhouse forcing, resulted in earlier emergence and flowering with higher quality plants. However, earlier applications, pre-chilling, tended to produce plants with more shoots. Overall, our experiments indicate that three weeks of chilling at 5°C (752 CU total) is a sufficient chilling regime for forcing 'Sarah Bernhardt' and 'Inspecteur Lavergne' peonies, and 1,000 CU of naturally accumulated chilling is sufficient for nursery production. GA3 applications can reduce the time to emergence and flowering, as well as increase the numbers of total shoots and flowering shoots. Timing of GA3 application is flexible; it can be applied right after rooting, before the chilling period, just before greenhouse forcing, or after shoots have begun to emerge. Plant growth retardant applications had a little effect on the growth of tested cultivars, but all plants treated with growth retardants are generally darker green in color. Additionally, growth retardant applications have some positive effects on flowering. / Doctor of Philosophy / Herbaceous peonies (Paeonia lactiflora Pall.) are common perennials used both in gardens and the landscape as well as for cut flowers. Peonies require a chilling period to break dormancy but not for flower bud differentiation. For all studies, two peony cultivars, Sarah Bernhardt and Inspecteur Lavergne, 3 to 5 eye small crowns from Holland were potted in 3.8-L pots in mid November of 2017 and 2018. Our overall objective was to determine if we could manipulate chilling time, along with application of gibberellic acid (GA3) and growth retardants, to produce marketable containerized peonies from a small crown in a single season (November to May). We evaluated chilling, GA3 and a growth retardant (uniconazole) under controlled chilling and greenhouse forcing conditions. We evaluated the effects of plant growth retardants (uniconazole or paclobutrazol) applied with different methods (fall drenches or spring sprenches) at different stages of production on the growth and development of containerized peony under nursery conditions. To determine the best timing for spring GA3 applications under nursery conditions, we applied three models based on natural chilling accumulation. We also evaluated GA3 effects on peony bud differentiation and development during controlled chilling and early forcing, as well as growth and flowering. Overall, 3 weeks chilling at 5°C [752 chilling units (CU) total] is a sufficient chilling regime for forcing 'Sarah Bernhardt' and 'Inspecteur Lavergne' peonies, and 1000 CU naturally accumulated chilling is sufficient for nursery production. GA3 applications can reduce the time to emergence and flowering, as well as increase the numbers of shoots and flowering shoots. Timing of GA3 application is flexible, it can be applied right after rooting, after the chilling period, or after shoots have begun to emerge. Plant growth retardant applications had little effect on plant growth of either cultivar, but all plants treated with growth retardants were darker green in color. Additionally, growth retardant applications had some positive effects on flowering.

Made available in DSpace on 2016-02-26T12:59:12Z (GMT). No. of bitstreams: 1 JackelineSchultzSoares.pdf: 419520 bytes, checksum: 681b65601587b028c9aa1b2b88798f13 (MD5) Previous issue date: 2010-02-18 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Orchidaceae differs of most botanical families by its seeds did not have enough reservations for germination. The present work aimed: 1. to study the influence of plant growth regulators BAP (6-benzylaminopurine) e GA3 (gibberellic acid), at concentrations of 0.0; 2.0 and 5.0 mg L-1, as pre-germinative treatment in the process of initial development of Dendrobium nobile Lindl seedlings; 2. to determine the volume of coconut water (0; 50; 100; 150 and 200 mL L-1), that, added to culture media, promoted better germination and in vitro cultivation of D. nobile. Seeds of D. nobile that were produced by manual self-pollinating were used as material of study. After six months of sowing and keeping in germination and growth chamber with controlled temperature and photoperiod (12 hours and 23 ºC ±), seedlings were removed from pots and evaluated about number, percentage of germination, fresh mass, height, diameter and number of psedobulbs, number of leaves, number of roots and length of the greatest root. Completely randomized experimental design was used. Every variables and vegetal attributes were submitted to variance analysis and when they were significative, to regression analysis. D. nobile seeds germinated more in the absence of plant growth regulators and treatments with BAP or GA3 for imbibitions of seeds influenced statistically in vitro development of D. nobile. The addition of 200 mL L-1 of coconut water to culture media promoted the best results for plant heights, number or roots, number of pseudobulbs and fresh mass of D. nobile. / Orchidaceae diferencia-se da maioria das famílias botânicas por suas sementes não possuírem reservas suficientes para a germinação. O presente trabalho objetivou: 1- estudar a influência dos reguladores hormonais BAP (6-benzilaminopurina) e GA3 (ácido giberélico), nas concentrações de 0,0; 1,0; 2,0 e 5,0 mg L-1, como tratamento pré-germinativo no processo de germinação e desenvolvimento inicial de plântulas de Dendrobium nobile Lindl; 2- determinar o volume de água de coco (0; 50; 100; 150 e 200 mL L-1 ), que, acrescido ao meio de cultura proporcionou melhor germinação e cultivo in vitro de D. nobile. Foram utilizadas como material de estudo sementes de D. nobile produzidas mediante autopolinização manual Após seis meses do semeio e permanência em câmara de germinação e crescimento com temperatura e fotoperíodo controlados (12 horas e 23 ºC ± 2) as plântulas foram retiradas dos frascos e avaliadas quanto ao número, porcentagem de germinação, massa fresca, altura, diâmetro e número de pseudobulbos, número de folhas, número de raízes e comprimento da maior raiz. Foi utilizado o delineamento experimental inteiramente casualizado. Todas as variáveis e atributos vegetais foram submetidos à análise de variância e quando significativos à regressão. As sementes de D. nobile germinaram mais na ausência de reguladores vegetais, e os tratamentos com BAP ou GA na embebição das sementes influenciaram 3estatisticamente o desenvolvimento in vitro de D. nobile. A adição de 200 mL L-1 de água de coco ao meio de cultura propiciou os melhores resultados para altura de plantas, número de raízes, número de pseudobulbos e massa fresca de D. nobile.

Made available in DSpace on 2016-02-26T12:59:35Z (GMT). No. of bitstreams: 1 JackelineSchultzSoares.pdf: 419520 bytes, checksum: 681b65601587b028c9aa1b2b88798f13 (MD5) Previous issue date: 2010-02-18 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Orchidaceae differs of most botanical families by its seeds did not have enough reservations for germination. The present work aimed: 1. to study the influence of plant growth regulators BAP (6-benzylaminopurine) e GA3 (gibberellic acid), at concentrations of 0.0; 2.0 and 5.0 mg L-1, as pre-germinative treatment in the process of initial development of Dendrobium nobile Lindl seedlings; 2. to determine the volume of coconut water (0; 50; 100; 150 and 200 mL L-1), that, added to culture media, promoted better germination and in vitro cultivation of D. nobile. Seeds of D. nobile that were produced by manual self-pollinating were used as material of study. After six months of sowing and keeping in germination and growth chamber with controlled temperature and photoperiod (12 hours and 23 ºC ±), seedlings were removed from pots and evaluated about number, percentage of germination, fresh mass, height, diameter and number of psedobulbs, number of leaves, number of roots and length of the greatest root. Completely randomized experimental design was used. Every variables and vegetal attributes were submitted to variance analysis and when they were significative, to regression analysis. D. nobile seeds germinated more in the absence of plant growth regulators and treatments with BAP or GA3 for imbibitions of seeds influenced statistically in vitro development of D. nobile. The addition of 200 mL L-1 of coconut water to culture media promoted the best results for plant heights, number or roots, number of pseudobulbs and fresh mass of D. nobile. / Orchidaceae diferencia-se da maioria das famílias botânicas por suas sementes não possuírem reservas suficientes para a germinação. O presente trabalho objetivou: 1- estudar a influência dos reguladores hormonais BAP (6-benzilaminopurina) e GA3 (ácido giberélico), nas concentrações de 0,0; 1,0; 2,0 e 5,0 mg L-1, como tratamento pré-germinativo no processo de germinação e desenvolvimento inicial de plântulas de Dendrobium nobile Lindl; 2- determinar o volume de água de coco (0; 50; 100; 150 e 200 mL L-1 ), que, acrescido ao meio de cultura proporcionou melhor germinação e cultivo in vitro de D. nobile. Foram utilizadas como material de estudo sementes de D. nobile produzidas mediante autopolinização manual Após seis meses do semeio e permanência em câmara de germinação e crescimento com temperatura e fotoperíodo controlados (12 horas e 23 ºC ± 2) as plântulas foram retiradas dos frascos e avaliadas quanto ao número, porcentagem de germinação, massa fresca, altura, diâmetro e número de pseudobulbos, número de folhas, número de raízes e comprimento da maior raiz. Foi utilizado o delineamento experimental inteiramente casualizado. Todas as variáveis e atributos vegetais foram submetidos à análise de variância e quando significativos à regressão. As sementes de D. nobile germinaram mais na ausência de reguladores vegetais, e os tratamentos com BAP ou GA na embebição das sementes influenciaram 3estatisticamente o desenvolvimento in vitro de D. nobile. A adição de 200 mL L-1 de água de coco ao meio de cultura propiciou os melhores resultados para altura de plantas, número de raízes, número de pseudobulbos e massa fresca de D. nobile.

This thesis deals with the exploration of the influence of various phytohormones, primarily the influence of abscisic acid on the process of maturation and the influence of auxin and gibberellin on the process of germination of two types of conifers, Abies alba and Picea abies, often used as a material in the discovery of somatic embryogenesis. Each genotype prefers specific concentration ABA. 15 uM and 45 uM is the most effective for the cell lines Abies alba; 15 uM and 30 uM ABA for Picea abies. Auxin (IBA) and gibberellin (GA3) did not support the growth of roots of Abies alba. The interaction between fungal cultures Paxillus involutus and Amanita muscaria and between the embryos during the germination was studied as well. Fungal culture Paxillus involutus had very fast speed of growth on the germination medium. Fungal culture Amanita muscaria was growing very slowly. The effect of fungi on the germination has not been observed.

<p> A quantitative study is made of the relative sensitivity of Phaseolus vulgaris var. Pinto to several different growth retardants, and to treatment of retarded plants with GA3. The growth of progeny from retarded plants is exam!ned and the cause of the transfer phenomenon is determined to be transfer of the growth retardants themselves to the progeny via the seeds, in some cases through to a third generation. </p> / Thesis / Master of Science (MSc)

L’oxyde de zinc dopé de type n est un excellent candidat pour la réalisation de films transparents et isolants thermiques grâce à ses propriétés d’absorption et de réflexion limitées aux domaines UV et IR. La synthèse en milieu polyol de particules nanostructurées d’oxyde de zinc dopé par du gallium a été utilisée afin de maîtriser la morphologie des cristallites. Il a été démontré expérimentalement et théoriquement que le maximum d’efficacité d’absorption IR est atteint pour un taux de dopant de 2,6 % molaire. Des suspensions de haute transmission dans le visible et absorption infrarouge significative ont été obtenues par l’encapsulation des particules avec un matériau fluoré d’indice de réfraction intermédiaire entre l’oxyde et le milieu dispersant, ainsi que par l’optimisation de l’état de dispersion de suspensions colloïdales grâce à l’adsorption de thioalcanes en surface des cristallites de ZnO dopés. / Thanks to its absorption / reflexion properties limited to the UV and the IR range, n-doped zinc oxide is a promising candidate for the elaboration of transparent and insulating films in smart windows. Nanostructured particles of Ga-doped zinc oxide were elaborated by polyol process. Polyol process was used in order to control the size and the morphology of the particles. Both experimental and theoretical data show that a maximum of IR absorption efficiency is obtained for a doping rate of 2.6 molar percent. Colloidal suspensions with high transmission in the visible range combined with significant absorption of the near infrared range were obtained using two strategies. The first one is the encapsulation of the Ga-doped ZnO particles by a fluoride shells with an intermediate refractive index between ZnO and the dispersion medium. The second one is the optimization of the dispersion state of nano-colloidal suspensions thanks to the adsorption of thioalkanes on the Ga-doped ZnO crystallite surfaces.

The growth of ornamental plant market in Brazil is remarkable nowadays with strong participation of Northeast region, particularly in Alagoas State on the commercialization of tropical flowers. Taking into account this economic aspect, it is of great importance for the productive chain of ornamental species the study of aspects of post harvest activities. Alpinia purpurata (Viell) K. Schum (Zingiberaceae) which occupies the second place in economic importance amongst tropical flowers. It is the main flower for growing and harvesting. The main objective of this research programme is to study the different aspects of Alpinia post-harvesting: (1) time of harvesting and cut of the basis of the stems, and (2) the use of solutions of pulsing ; and/or maintenance of the floral stem by using: (2.1.) biocide compounds and pH of the solution; (2.2) carbohydrates and carbohydrates plus biocides; (2.3) anti-ethylene compounds and antiethylene compounds plus carbohydrates; (2.4) elements as calcium and silicon; and (2.5) senescence retarding growth regulators. It was evaluated the influence of these factors in the water relations, quality and longevity of the stems. Six experiments were carried out in the laboratory (CECA) of the Federal University of Alagoas. In the first experiment, the stems were harvested in three different times and they were cut periodically on their basis. In the second experiment different biocide substances were tested (8- hydroxyquinoline sulphate, aluminum sulphate, salicilic acid and sodium hipocloride) associated to pH variation of the maintenance solution. In the third experiment the stems received sucrose solutions pulsing from 2 to 20% for 12, 24 and 48 hours, following by maintenance in distilled water or in solution of 8- hidroxikinolin (HQS). The fourth experiment comprised three times of exposition (30, 60 and 120 min) with STS 1mM following by the presence or absence of pulsing in sucrose 20% for 12 hours. In the fifth experiment it was evaluated the effect of the addition of Ca (calcium sulphate 50 and 100mM), Si (sodium silicate 1,25 and 2,50 mM) and Ca+Si in maintenance solution. In the sixth experiment the stems were submitted to gibberellins, solutions (GA3), 10, 30 and 60 μm and cytokinin (benzyladenine 6-BA), 10, 20 and 100μm in 24 hours pulsing under continuous light. In all experiments the fresh biomass and the quality (scale of values) of the stems were determined daily or every two days until the end of the experiment. The amount of water was also determined for the floral bracts and dry biomass. The experiments were analised by completely randomized design and the data submitted to the variance analysis, test of averages and , when necessary, to the regression analysis. It was observed that the stems harvested at the end of the afternoon had shown greater commercial value; however, the regular cuts of the basis of the stems reduced their longevity. The use of HQS provided greater durability and humidity of the stems. On the other hand the other biocides did not improve the quality when compared to the control. The reduction of the pH by using citric acid did not interfere with the studied parameters. The use of sucrose in pulsing was only effective when the stems had been kept in distilled water. In this case the concentration sucrose of 20% for 12 hours showed better results. Silver thiosulphate when in pulsing for 30 minutes produced an increase of water contents and for 60 minutes or plus, or when addition of sucrose, caused dehydration of the stems. The only use of calcium sulphate or in association with sodium silicate in maintenance solution caused high improvement of the quality of the stems in comparison to the control and sodium silicate treatment. The use of cytokinin and gibberellins even considering it improved the water contents of the stems did not affect the commercial durability of them. / É notável o crescimento do mercado de plantas ornamentais no Brasil. Com participação efetiva da região Nordeste, destacando-se as exportações de flores tropicais, onde o Estado de Alagoas vem se firmando, com Alpinia purpurata (Viell) K. Schum (Zingiberaceae) como a principal flor de corte, e que ocupa o segundo lugar em importância econômica dentre as flores tropicais. Levando-se em conta esse aspecto econômico, verifica-se ser de grande importância para a cadeia produtiva desses cultivos, o estudo de aspectos relativos à da pós-colheita. Assim sendo, a presente pesquisa, objetivou estudar diferentes aspectos do manejo pós-colheita dessas flores, testando: (1) hora de colheita e corte da base das hastes, e (2) o uso de soluções de pulsing ; e/ou manutenção das hastes florais - neste caso ainda associado (2.1) a substâncias biocidas com o pH na solução sob controle; (2.2) a carboidratos e carboidratos mais biocidas; (2.3) a substâncias anti-etileno e substâncias anti-etileno mais carboidratos; (2.4) a elementos como cálcio e silício; e (2.5) a fitorreguladores retardantes da senescência. Avaliou-se a influência destes fatores nas relações hídricas, qualidade e longevidade das hastes cortadas, através de seis experimentos em laboratório no Centro de Ciências Agrárias da Universidade Federal de Alagoas (CECA/UFAL). No primeiro experimento, as hastes foram colhidas em três diferentes horários, recebendo durante o período pós-colheita cortes periódicos na base da haste. No segundo experimento, foram testadas substâncias biocidas (Sulfato de 8- hidroxiquinolina, Sulfato de alumínio, Ácido salicílico, Hipoclorito de sódio) associadas à redução ou não do pH. No terceiro experimento as hastes receberam tratamento de pulsing com soluções de sacarose entre 2 e 20%, por períodos de 12, 24 e 48 h, seguidas de manutenção em água destilada ou em solução de 8-hidroxiquinolina (HQS) comparando-se com duas testemunhas (água destilada ou solução de HQS). No quarto experimento, foram testados três tempos de exposição (30, 60 e 120 minutos) a STS 1mM, seguido ou não de pulsing em sacarose a 20%, por 12 horas. No quinto experimento, foram verificados os efeitos da adição de Ca (sulfato de cálcio a 50 e 100mM), Si ( silicato de sódio a 1,25 e 2,50 mM) e Ca+Si em solução de manutenção. No sexto experimento, as hastes foram submetidas a soluções de SILVA, A.T.C. 2006 Manejo pós-colheita de alpinia purpurata (Vieill) K. Schum (zingiberaceae)... xv giberelina (GA3), a 10, 30 e 60 μM e citocinina (benziladenina 6-BA), a 10, 20 e 100 μM em pulsing por 24 horas, sob luz contínua. Em todos os experimentos, a massa fresca e a qualidade (com base em notas) das hastes foram determinadas diariamente, ou a cada 2 dias; no final de cada experimento foram também determinados o conteúdo relativo de água das brácteas florais e a massa seca das hastes. O delineamento utilizado foi o inteiramente casualizado sendo os dados submetidos à análise de variância, teste de médias e, quando necessário, à análise de regressão. As hastes cortadas ao final da tarde tiveram maior durabilidade comercial, porém o corte periódico da base das hastes reduziu sua longevidade. O uso de HQS proporcionou maior durabilidade e hidratação das hastes, sendo que os demais biocidas testados não melhoraram a qualidade. A redução do pH, pelo uso do ácido cítrico, não influenciou nas variáveis estudadas. O uso de sacarose em pulsing só foi efetivo quando as hastes foram mantidas em água destilada, sendo melhor o resultado para a concentração de 20% por 12 horas. O tiossulfato de prata em pulsing por 30 minutos, promoveu um aumento de hidratação, mas desidratou as hastes a 60 minutos ou mais ou quando adicionado à sacarose. O uso de sulfato de cálcio em solução de manutenção e quando associado ao silicato de sódio promoveu elevada melhoria de qualidade das hastes. O uso de citocininas e giberelinas embora tenha melhorado as relações hídricas das hastes não afetou a durabilidade comercial das mesmas.

L'oxyde de zinc dopé de type n est un excellent candidat pour la réalisation de films transparents et isolants thermiques grâce à ses propriétés d'absorption et de réflexion limitées aux domaines UV et IR. La synthèse en milieu polyol de particules nanostructurées d'oxyde de zinc dopé par du gallium a été utilisée afin de maîtriser la morphologie des cristallites. Il a été démontré expérimentalement et théoriquement que le maximum d'efficacité d'absorption IR est atteint pour un taux de dopant de 2,6 % molaire. Des suspensions de haute transmission dans le visible et absorption infrarouge significative ont été obtenues par l'encapsulation des particules avec un matériau fluoré d'indice de réfraction intermédiaire entre l'oxyde et le milieu dispersant, ainsi que par l'optimisation de l'état de dispersion de suspensions colloïdales grâce à l'adsorption de thioalcanes en surface des cristallites de ZnO dopés.