Root system morphology of ipê-roxo tree grown in soil subjected to phosphorus application in subtropical climate region

Phosphorus (P) availability in subtropical soils does not often meet the nutritional demand of native tree species such as the ipê-roxo tree (Handroanthus heptaphyllus); therefore, it is necessary to supply P at planting. However, the impact of P on root system growth remains unknown. The aim of the current study was to investigate the effect of P application on root morphology of H. heptaphyllus plants over a 36-month period in a subtropical climate region. During the experiment, the plants subjected to fertilization with 40 kg P ha−1 were compared to untreated control. Plant roots were scanned through minirhizotron system 18 and 36 months after transplant (MAT), and generated images were used to determine total root length, mean root diameter and total root volume. Plant height and leaf P concentrations were also evaluated. Phosphorus application enhanced root and whole plant growth with a more evident effect at 36 MAT, when soil P availability decreased. The results give important information on the cultivation of H. heptaphyllus plants in soils presenting low P availability

Kinetic parameters related to nitrogen uptake efficiency of pear trees (Pyrus communis).

Genetic improvement programs for pear trees in Brazil are characterized by rootstock (hypobiotic) selection mainly considering physiological attributes such as vigor, breakage of dormancy, propagation easiness, and sanitary characteristics, such as resistance to pests and diseases. However, kinetic parameters that determine nutrient uptake efficiency are not usually considered as, for example, nitrogen (N) in forms of NO3 − and NH4 +. The objective of this study was to evaluate the kinetic parameters related to N uptake in pear selection '54′ and '971′ as additional criteria for rootstock selection. The plants were acclimatized in a half-strength Hoagland solution and tested to assess the depletion of the internal reserves at 15 and 30 days, in CaSO4 solution to evaluate the depletion period during 65 h. The selection '971′ showed more significant NO3 − and NH4 + uptake efficiency, because presented higher Vmax values and Influx. The internal reserve depletion (IRD) period for the evaluated selections was 30 days in CaSO4 solution. The evaluation period of the depletion period to reach the Cmin for selections '971′ and '54′ was 64 and 65 h for NO3 − respectively, and 65 h for NH4 +. The selection '971′ had a higher affinity with the NO3 − ion when correlated with the physiological parameters of minimum fluorescence (Fo) and electron transport rate (ETRm)

Fertirrigação e lixiviação de nitrogênio em solo arenoso de vinhedo.

XV Congresso Latino-Americano de Viticultura e Enologia E XIII Congresso Brasileiro de Viticultura e Enologia. Bento Gonçalves-RS, 3 a 7 de Novembro de 2015

Calagem, adubação e estado nutricional em videiras.

A área cultivada com videira no Brasil e, especialmente, no Sul do país, como no Rio Grande do Sul (RS) e Santa Catarina (Se), tem aumentado nos últimos anos. Porém, na maioria dos casos os solos são ácidos e possuem baixa fertilidade natural. Por isso, torna- se necessário, quando diagnosticada a necessidade, a aplicação de corretivos da acidez do solo e adubações. Mas, estas práticas devem ser realizadas seguindo as recomendações técnicas oficiais recomendadas para a cultura da videira, pois normalmente afetam a produção e qualidade da uva, bem como do mosto e de seus subprodutos, como o vinho, sucos e espumantes. Considerando esta problemática, no presente capítulo serão apresentadas informações técnicas sobre calagem, adubações e composição nutricional de videiras. Além disso, serão apresentados resultados de pesquisa mais recentes sobre a dinâmica de nutrientes em solos de vinhedos, bem como o impacto de nutrientes sobre as características físicas e químicas do vinho, temática ainda pouco estudada no Brasil. Com todas as informações esperamos contribuir para um sistema de produção vitivinícola mais produtivo, com uvas e seus subprodutos com melhor qualidade requisitada pelo consumidor, mas com baixo potencial de risco ambienta I

Kinetic parameters govern of the uptake of nitrogen forms in "Paulsen" and "Magnolia" grapevine rootstocks.

Grapevine rootstocks are selected according to graft compatibility, pathogen tolerance and water stress. However, morphological and kinetic parameters of nutrient absorption, such as nitrate (NO3 −) and ammonium (NH4 +), usually are not considered. The study aimed to select, based on morphological and kinetic absorption parameters, grapevine rootstocks with greater efficiency of N-forms absorption. The study was performed with two grapevine rootstocks (?Paulsen 1103? and ?Magnolia?), grown in Hoagland nutrient solution in a greenhouse. After 21 d, they were placed in 0.05 mol L-1 CaSO4 solution for 20 d to exhaust nutrient internal reserves. The rootstock with highest NO3 − and NH4 + uptake efficiency was ?Paulsen 1103?, since it presented lower Cmin and Km values in the two N forms, allowing N extraction by roots, even in low concentrations in solution, due to the higher transporter affinity for NO3 − and NH4 + in roots from rootstock. ?Paulsen 1103? rootstock also presented better photosynthetic performance and root development, collaborating for greater growth and mass production than 'Magnolia' rootstock. On the other hand, ?Magnolia? rootstock showed higher NO3 − and NH4 + Cmin and Km values than ?Paulsen? rootstock, which shows lower transporters affinity for these ions. Results demonstrate the importance of the use of NO3 − and NH4 + uptake kinetic parameters in grapevine rootstock selection programs, since these may serve as indicator of plant's ability to absorb NO3 − and NH4 + in low concentrations

Procedimentos para avaliação de parâmetros cinéticos na absorção de nutrientes em videiras.

A maioria dos solos são carentes de nutrientes e exigem adubações. E as espécies e variedades cultivadas também podem apresentar baixa eficiência na absorção dos nutrientes, prejudicando o crescimento, produtividade e qualidade dos frutos. Como consequência, parte dos nutrientes aplicados via adubações pode ser desperdiçado, contribuindo com perdas e contaminações. Por isso, metodologias que contribuem para a seleção de genótipos mais eficientes na absorção de nutrientes, especialmente das formas de nutrientes mais móveis nos solos, são de extrema importância. Esta publicação apresenta uma metodologia inovadora para estimar os parâmetros cinéticos da absorção de nutrientes em videiras ainda no estágio de mudas, envolvendo a velocidade máxima de absorção, a constante de Michaelis-Menten, a concentração mínima e o influxo. A análise conjunta desses parâmetros cinéticos permite definir quais as variedades ou seleções avançadas possuem potencial para se adaptar aos solos com baixa fertilidade natural, ou mesmo, que podem receber menores doses de nutrientes, racionalizando o manejo da adubação e diminuindo os custos de produção

Morphological and kinetic parameters of the uptake of nitrogen forms in clonal peach rootstocks.

Peach (Prunus persica L.) rootstock cultivars are typically selected for scion compatibility, ease of propagation, vigor, development, flowering season, yield, low need for cold temperatures, resistance to diseases, effects on the physical-chemical characteristics of the fruit, plant longevity and adaptation to adverse edaphoclimatic conditions. However, kinetic parameters related to nutrient uptake efficiency are usually not considered, such as those of nitrate (NO3 −) and ammonium (NH4 +). N is the nutrient that most impacts growth and yield. The objective of this study was to show the importance of the kinetic parameters of NO3 − and NH4 + uptake as additional criteria for selecting peach rootstocks. The experiment was conducted in a greenhouse. Three rootstock (?Aldrighi?, ?Tsukuba1? and ?Clone 15′) were grown for 30 days in a pot containing 0.1 mol L-1 CaSO4 solution to reduce internal reserves of N. Afterwards, the plants were placed in Hoagland nutrient solution, where periodic collections of the nutrient solution were carried out for three days and the concentrations of NO3 − and NH4 + were determined. After the third day of collecting the solution, the plants were collected and then separated into leaves, roots and stems. Dry matter and total N content were assessed. The kinetic parameters related to NO3 − and NH4 + uptake (maximum uptake rate - Vmax, affinity constant - Km, Minimum concentration - Cmin, Influx - I) were calculated using Cinética software. The most efficient rootstock for NO3 − and NH4 + uptake was ?Tsukuba1?, as it showed the lowest values of Cmin and Km and the highest values of Vmax and Imax for NO3 − and NH4 +. NO3 − uptake in ?Tsukuba1? and ?Aldrighi? showed a two-phase uptake pattern, suggesting the presence of low and high affinity transport systems. On the other hand, NH4 + uptake in the three cultivars apparently followed a one-phase uptake pattern, suggesting the presence of a high affinity transport system. The kinetic parameters of NO3 − and NH4 + uptake are additional criteria that can be used in selecting peach rootstocks, as they directly influence shoot and root dry matter production and N accumulation in leaves.Made available in DSpace on 2019-01-11T00:09:02Z (GMT). No. of bitstreams: 1 Morphologicalandkineticparametersoftheuptakeofnitrogenforms.pdf: 258155 bytes, checksum: 54f6474675598af2e1168230ec044329 (MD5) Previous issue date: 2019-01-09bitstream/item/190113/1/Morphological-and-kinetic-parameters-of-the-uptake-of-nitrogen-forms.pd

Contribution of nitrogen from urea applied at different rates andtimes on grapevine nutrition.

In Brazilian vineyards planted in sandy soils, nitrogen (N) should be applied at optimal rates and timing that correspond to greatest demand, thus minimizing N losses. The aim of this study was to evaluate the grapevine N distribution and recovery of urea-15N applied at budding and bloom. In 2009, in a vineyard (Vitis vinifera cv. Cabernet Sauvignon) planted in Santana do Livramento, south Brazil, grapevines were treated with 10 kg N ha?1 at budding +10 kg N ha?1 at full bloom (10B + 10F); 20 kg N ha?1 at budding +20 kg N ha?1 atfull bloom (20B + 20F); 20 kg N ha?1 at budding (20B); and 40 kg N ha?1 atfull bloom (40F). Budding of grapevines in 2009 and 2010 was atthe end of August and full bloom in November. In February 2010 and 2011, grapevine organs (leaves, berries, stem and roots) were collected, and in February 2011 soil samples were also collected in the profile. The wine-producing grapevines grown in the sandy soil took up more N derived from 20B treatment, compared with other N treatments, especially in the first crop season. The N derived from fertilizer applied at different rates and time was preferentially distributed in annual plant organs, but most N contained in the plant organs was derived from other sources than the fertilizer N. In the following season, 15N applied in the previous year was recovered preferentially in leaves and fruits, again in low amounts. Nitrogen derived from fertilizer applied at different rates and time in a sandy soil apparently contributes little to grapevine nutritio

Contribution of nitrogen from urea applied at different rates andtimes on grapevine nutrition.

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