Linking Landscape, Environment, Agriculture and Food

Funder

Organizational Unit

Publications

Half Friend, Half Enemy? Comparative Phytophagy between Two Dicyphini Species (Hemiptera: Miridae)

Publication . Souto, Paula; Abraços-Duarte, Gonçalo; Borges da Silva, Elsa; Figueiredo, Elisabete

Despite their importance as biological control agents, zoophytophagous dicyphine mirids can produce economically important damage. We evaluated the phytophagy and potential impact on tomato plants of Dicyphus cerastii and Nesidiocoris tenuis. We developed a study in three parts: (i) a semi-field trial to characterize the type of plant damage produced by these species on caged tomato plants; (ii) a laboratory experiment to assess the effect of fruit ripeness, mirid age, and prey availability on feeding injuries on fruit; and (iii) a laboratory assay to compare the position of both species on either fruit or plants, over time. Both species produced plant damage, however, although both species produced scar punctures on leaves and necrotic patches on petioles, only N. tenuis produced necrotic rings. Both species caused flower abortion at a similar level. Overall, N. tenuis females produced more damage to tomato fruit than D. cerastii. There was an increased frequency of D. cerastii females found on the plants over time, which did not happen with N. tenuis. Our results suggested that, although D. cerastii caused less damage to fruit than N. tenuis, it still fed on them and could cause floral abortion, which requires field evaluation and caution in its use in biological control strategies

2022Journal article

Open access

Chitin-Glucan Complex Hydrogels: Optimization of Gel Formation and Demonstration of Drug Loading and Release Ability

Publication . Araújo, Diana; Rodrigues, Thomas; Delgado Alves, Vitor; Freitas, Filomena

Chitin-glucan complex (CGC) hydrogels were fabricated through a freeze–thaw procedure for biopolymer dissolution in NaOH 5 mol/L, followed by a dialysis step to promote gelation. Compared to a previously reported methodology that included four freeze–thaw cycles, reducing the number of cycles to one had no significant impact on the hydrogels’ formation, as well as reducing the total freezing time from 48 to 18 h. The optimized CGC hydrogels exhibited a high and nearly spontaneous swelling ratio (2528 +- 68%) and a water retention capacity of 55 +- 3%, after 2 h incubation in water, at 37 ºC. Upon loading with caffeine as a model drug, an enhancement of the mechanical and rheological properties of the hydrogels was achieved. In particular, the compressive modulus was improved from 23.0 +-0.89 to 120.0 +- 61.64 kPa and the storage modulus increased from 149.9 +- 9.8 to 315.0 +- 76.7 kPa. Although the release profile of caffeine was similar in PBS and NaCl 0.9% solutions, the release rate was influenced by the solutions’ pH and ionic strength, being faster in the NaCl solution. These results highlight the potential of CGC based hydrogels as promising structures to be used as drug delivery devices in biomedical applications

2022Journal article

Open access

Emissões de gases com efeito de estufa de um pomar de macieiras fertilizado com efluentes pecuários

Publication . Costa, Eva Renata Cardoso; Fangueiro, David; Ribeiro, Henrique

A agricultura é um setor que em muito contribui para a emissão de gases com efeito de estufa (GEE), onde para muitas culturas, como é o caso da macieira, existem poucos ou nenhuns estudos sobre as emissões de GEE em cenários de fertilização orgânica utilizando diferentes efluentes pecuários. Neste estudo determinou-se os fluxos de emissão do CO2, CH4 e N2O de um pomar de macieiras, parcialmente fertilizado com efluentes pecuários, sobre um clima Mediterrâneo. Foram utilizados 5 tratamentos: controlo (100% fertilização mineral), chorume de bovino, chorume de bovino acidificado, estrume de bovino e estrume de aves, todos na proporção de 50% de efluente e 50% de fertilização mineral, de forma a suprir a necessidade azotada da cultura igual a 80 kg de N disponível ha-1. As medições dos fluxos de GEE foram realizadas entre março e agosto, com a determinação da concentração de cada um dos gases através de um equipamento fotoacústico. Não se verificou diferenças significativas (p<0,05) na produção da cultura pela utilização dos efluentes pecuários. As emissões de CH4 variaram entre 398,37 mg C-CH4 m-2 com chorume de bovino acidificado e 4451,42 mg C-CH4 m-2 com chorume de bovino não acidificado. A emissão cumulativa de N2O mais baixa foi obtida com o tratamento de controlo, 300,13 mg N-N2O m-2, e a mais elevada com estrume de aves, 3412,07 kg N-N2O m-2. Em relação ao CO2, as emissões variaram entre 296,48 g C-CO2 m-2 com o controlo e 929,63 g C-CO2 m-2 com estrumes de aves. No balanço global, o estrume de aves emitiu o maior valor cumulativo de CO2e. A acidificação do chorume de bovino mostrou ser muito eficaz na mitigação das emissões de CH4. O teor de água no solo foi o principal fator que influenciou as emissões

2022Master thesis

Open access

Historical and Heritage Sustainability for the Revival of Ancient Wine-Making Techniques and Wine Styles

Publication . Harutyunyan, Mkrtich; Malfeito-Ferreira, Manuel

The purpose of this review is to provide a general description of ancient winemaking techniques and wine styles that were most lauded in antiquity, in support of their revival and dissemination today. From the first fully excavated winery, dating from the late fifth to the early fourth millennium BC, the gentle crushing of grapes by foot and the probable absence of maceration indicate that most wines were made with the aim of reducing astringency. The oxidative nature of winemaking would have resulted in rapid browning, so that wines made from red grapes would have had a similar color to those made from white grapes after being aged in clay vats for several years. The difficulty in preventing the wine surface contact with the air would have resulted in biological ageing under the yeast pellicle being a common occurrence. This phenomenon was not considered a flaw, but a characteristic feature of highly prized wines. Dried grapes were used to make sweet wines, which were also highly prized, therefore justifying the construction of dedicated facilities. The addition of boiled juices, salt, resins, mixtures of herbs, spices, fruit juices, flowers, or honey to the wines would have increased their taste pleasantness while improving their preservability and medicinal properties. Indeed, today’s preference for flavored wines with a soft mouthfeel seems to have been representative of the ancient elite consumers. Overall, the technical interpretation of winemaking described in this review will provide solid historical support for the current rebirth of ancient production methods, particularly those using pottery vessels

2022Journal article

Open access

Phosphorus concentration and speciation in urban wastewater for potential recovery

Publication . Santos, A. F.; Gando-Fereira, L. M.; Quina, M. J.; Alvarenga, P.

Phosphorus (P) scarcity, jointly with eutrophication problems and water shortage, are forcing urban wastewater treatment plants (WWTP) to redirect their focus to nutrient recov-ery and treated water reuse. However, before implementing any recovery approach, it is neces-sary to understand the problem and its variability. In this scope, this work aims to collect data from different WWTP to assess P concentrations, speciation, and variability in urban wastewater. The analysis revealed high levels of total P, before and after anaerobic digestion, and in the sludge dewatering water (100-400 mg P/L), with about 60-80% of total P in the solu-ble form. Also, in the best-case scenario, soluble reactive P (orthophosphate) accounts for over 50% of soluble total P. Preliminary results showed that it would be possible to recover over 100 kg P/day in a WWTP with about 160,000 p.e.

2023Book part

Restricted access