Efeito da aplicação de diferentes doses de um extrato de algas em oliveiras Arbequina e Cobrançosa

• Author(s): Garcia, Catarina Isabel Rola
• Date: 2015
• Persistent ID: http://hdl.handle.net/10400.5/10916
• Origin: Repositório da UTL
• Subject(s): nitrate reductase; glutamine synthetase; Olea europaea L.; SPAD; seaweed extract
• Document Type: Master thesis
• Language: Portuguese
• Advisor(s): Mota, Mariana Gomes
• Contributor(s): Repositório da Universidade de Lisboa

Description

Mestrado em Engenharia Agronómica - Hortofruticultura e Viticultura - Instituto Superior de Agronomia

The present work aimed to study the effect of the application of biostimulant Goёmar Olivos, from Selectis, in the efficiency of use of nitrogen forms (nitrate and ammonium) in the olive cultivars Arbequina and Cobrançosa. This assessment was made indirectly by determination of enzymatic activities of nitrate reductase (NR) and glutamine synthetase (GS) in leaves and reproductive organs of the olive trees and the quantitation of chlorophyll content in the leaves (related to the nitrogen content) measured with the equipment SPAD (soil analysis plant development). The field trial was held in Quinta Vale de Lobos, in Santarém, in a hedgerow olive grove of Arbequina and Cobrançosa, and two treatments were compared (single dosis: two applications of 2.5l/ha each, according to the manufacturer’s instructions, the first at the onset of development after winter, the other at full bloom; double dosis: a single application of 5l/ha at full bloom) with a control (water application). For enzyme activities, leaf and reproductive organ samples were taken from the period before full bloom to the hardening of the seed. Measurements with SPAD were made during May in newly expanded leaves of three treatments. Enzyme assays and SPAD assessments did not show, in any of the cultivars, a clear benefit deriving from the application of the biostimulant. The determination of enzyme activities over time revealed major peaks in full bloom and to the hardening of the seed, stages when the reproductive organs are constituted as strong sinks. SPAD measurements in the leaves of both cultivars were inconclusive, probably due to the difficulty inherent to the color of olive leaves. Some oscillations that were observed can be related to temperature variations, which affect the metabolic activity in plants