Typescript. / Thesis (Ph. D.)--University of Hawaii, 1965. / Bibliography: leaves [69]-72. / v, 72 l illus., tables

Copies of author's previously published articles inserted. / Bibliography: leaves 93-107. / viii, 108, 69 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Provides evidence for a specific, regulated, high affinity mechanism for entry of calcium and other divalent cations into the roots of wheat. / Thesis (Ph.D.)--University of Adelaide, Dept. of Botany, 1996?

Orientador: Roberto Lyra Villas Bôas / Banca: Poliana Rocha D' Almeida Mota Suares / Banca: Caroline de Moura D Andréa Mateus / Resumo: Com o objetivo de avaliar o desenvolvimento e produção do cultivar 'Gaston' submetido a doses de cálcio e potássio, utilizando extratores de solução do solo, instalou-se a presente pesquisa em vasos na estufa agrícola do Departamento de Solos e Recursos Ambientais da Universidade Estadual Paulista "Júlio de Mesquita Filho" - Campus de Botucatu. Com delineamento em blocos casualizados e quatro repetições, foi conduzido um experimento testando quatro doses de Ca (98 kg.ha-1, 196 kg ha-1, 294 kg ha-1 e 392,0 kg ha-1) e outro experimento com 4 doses de K2O (363 kg ha-1, 726 kg ha-1, 1088 kg ha-1 e 1451 kg ha-1) aplicados via fertirrigação por gotejamento. Foram avaliados: a extração semanal da solução do solo, altura da planta, concentração de nutrientes (folha, fruto e solo) e produção. Os extratores permitiram monitoramento eficiente e houve diferença significativa entre os tratamentos. O aumento da concentração de sais na solução do solo reduziu a altura das plantas, número de frutos e a produção. As doses, além da calagem, que proporcionaram maior produção de frutos foram: 98 kg ha-1 de Ca com 46,5 t ha-1 e 363 kg ha-1 de K2O com 39,2 t ha-1. / Abstract: With the objective of evaluating the development and production of 'Gaston' cultivar submitted to calcium and potassium doses, use soil solution extractors, the present research in pots in the greenhouse of the Department of Soils and Environmental Resources of the State University Paulista "Júlio de Mesquita Filho" - Campus of Botucatu. A randomized complete block design with four replications was carried out by testing four Ca doses (98 kg ha-1, 196 kg ha-1, 294 kg ha-1 and 392.0 kg ha-1 ) and another experiment with 4 doses of K2O (363 kg ha-1, 726 kg ha-1, 1088 kg ha-1 and 1451 kg ha-1 ) applied via drip fertigation. Was evaluated: a weekly extraction of soil solution, plant height, nutrient concentration (leaf, fruit and soil) and production. The extractors allowed efficient monitoring and great difference between the treatments. Increasing the concentration of salts in the soil solution reduced plant height, number of fruits and yield. The doses, besides liming, that provide higher fruit yield: 98 kg ha- 1 of Ca with 46.5 t ha-1 and 363 kg ha-1 of K2O with 39.2 t ha-1 ... / Mestre

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Orientador: Sarita Leonel / Banca: Marco Antonio Tecchio / Banca:Luis Lessi dos Reis / Resumo: A escolha dos cultivares mais adaptados, de menor exigência em frio, é fundamental para o cultivo do pessegueiro em regiões subtropicais do Brasil. Estas regiões, de inverno ameno, não atende a necessidade em frio destas plantas, sendo necessário a utilização de técnicas alternativas, como a aplicação de produtos químicos posteriormente a poda de frutificação, para induzir a brotação das plantas. Entretanto, no mercado ainda existem poucos produtos disponíveis para esta finalidade, restringindo as opções do fruticultor a um número reduzido de moléculas químicas, que muitas vezes apresentam elevada toxicidade ao aplicador. Dentro deste contexto, objetivou-se com o presente trabalho avaliar o desempenho agronômico e a qualidade de frutos de três cultivares de pessegueiro, submetidos à aplicação de fertilizante foliar nitrogenado (Erger®) e nitrato de cálcio para a indução da brotação das plantas. O trabalho foi realizado na Faculdade de Ciências Agronômicas da Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP) - campus Botucatu, São Paulo. O município está situado a 22º51'55"S, 48º27'22" O e a 810 m de altitude. Foram avaliados cultivares de pessegueiro, com 4 anos de idade. As plantas foram conduzidas em taça, com espaçamento 6,0 x 4,0 m e enxertadas no porta-enxerto 'Okinawa'. Os tratamentos corresponderam a 3 cultivares: Douradão, BRS Kampai e BRS Rubimel e 4 doses de fertilizante foliar nitrogenado (FFN): 0; 1,25; 2,50 e 3,75%, ambas associadas a 4% de nitrato... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Choosing a low-chill variety is fundamental for growing peaches under subtropical conditions, since Brazil does not present enough cold weather; therefore, alternative techniques is required, such as the application of chemical products after fruit pruning to stimulate sprouting. However, there are still few products available for this purpose in the market; restricting options for producers to a reduced number of chemical molecules, which is poisoning for applicators. Thus, the current study aimed to evaluate the agronomic performance and fruit quality of three peach varieties, submitted to nitrogen fertilizer (Erger®) and calcium nitrate to induce sprouting. The study took place at School of Agriculture, Botucatu São Paulo State University (UNESP), São Paulo; located at the following coordinates: 22º51'55"S, 48º27'22"W and an altitude of 810 m. Peach trees of four years old were potted, spaced at 6 x 4 m on graft site of rootstock with 'Okinawa'. Treatments corresponded to three cultivars: Douradão, BRS Kampai and BRS Rubimel and 4 levels of foliar nitrogen fertilizer (FNF) (0; 1.25; 2.50 and 3.75%); associated with 4% calcium nitrate. Treatments received fertilizer immediately after pruning (July 15, 2015). A randomized block design with 12 treatments, 4 repetitions and 2 plants per plot totalized 96 plants; thus, 3 cultivars and 4 levels of FNF in a factorial scheme. Data were analysed through analysis of variance and, when significant, means were compared through Tukey test for cultivars and by polynomial regression for FNF levels. Results indicated an application of 2.2% FNF associated with 4% calcium nitrate to induce sprouting, flowering and fruiting in all cultivars; being "BRS Rubimel" the most productive and recommended in the respective area. FNF levels has not interfered in the cycle of those cultivars. For a period between dormancy and end of harvest, an accumulation of 1687.20 .. / Mestre

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Sugar maple (Acer saccharum Marsh.) has experienced diebacks in many parts of its range; these declines have caused researchers to consider the many connected factors governing tree health. Altered availability of base cations due to acidic deposition and climatic extremes (drought, late winter freeze-thaw cycles) have been identified as two main causal stressors. To predict the role of climate on Ca nutrition, I investigated the relationship between the climatic factors of temperature, precipitation, water availability and windstorm on temporal changes to depth of Ca source of sugar maple. I hypothesized that the Ca uptake depth would be deeper after windstorms, or under dry or cold conditions, and shallower under warm or wet conditions. The ratio of Ca/Sr can be used to track the source of Ca. Calibration of the relationship between soil and plant Ca/Sr was done by analyzing Ca/Sr ratios in soil extracts of various strengths (H2O, NH4Cl, and ammonium EDTA) and in seedlings of sugar maple grown from natural regeneration on 37 differing sites. The relationships between soil extract Ca/Sr ratios and leaf and stem Ca/Sr ratios were linear, and the slopes of these relationships were different. These findings support the use of Ca/Sr as a tracer to Ca and they highlight the need to calibrate the technique for the plant tissue and the soil extractant used. This technique was then applied to study Ca uptake depth and its relationship with climate in the Hermine watershed, a sugar maple dominated forest in southern Quebec. The Ca/Sr was measured in soil, incremental cores of wood, and leaves. The ratio of Ca/Sr from nine soil profiles decreased with soil depth (r2 = 0.320, p<0.05), providing a signature for depth. Wood cores from ten trees were analysed in five or ten year increments from 1940 to 1999 to provide a long-term trend of Ca nutrition. Sugar maple leaves from 1995-2005 from the same 25 trees were analyzed to determine the annual dynamics of Ca uptake depth and its relationship with climate. Results suggest that the majority of tree Ca is taken from the lowest part of the rooting zone, regardless of the climatic conditions that occurred during this study, although the minor variations were related to the April temperature (r2 = 0.208, p = 0.023) and the June, July and August combined total precipitation (r2 = 0.581, p = 0.006). The effect of the windstorm on Ca uptake depth was only apparent in the area of the forest most visibly affected; Ca uptake was deeper.

Typescript. / Thesis (Ph. D.)--University of Hawaii, 1967. / Bibliography: leaves 145-152. / xiii, 152 l illus., tables