OAR@UM Community:

Assessing climate variability and association with agricultural productivity in Malta (2000-2021)

Thu, 01 Jan 2026 00:00:00 GMT

Title: Assessing climate variability and association with agricultural productivity in Malta (2000-2021) Authors: Attard, George; Galdies, Charles; Meli, Anthony Abstract: The Mediterranean Basin is among the regions most exposed to climate-related risks to agriculture, owing to the combined effects of warming, increasing hydroclimatic variability and water scarcity. Malta is particularly vulnerable because of its semi arid climate, limited land and freshwater resources, and substantial dependence on groundwater and supplementary irrigation. This study examines observed temperature and precipitation trends and their temporal association with agricultural production in Malta during 2000-2021, with an emphasis on the autumn-winter period that is critical for the establishment of major arable crops. Monthly temperature and precipitation observations were evaluated alongside national agricultural statistics for cereals, potatoes, tomatoes, vines and broader crop categories. The analysis indicates a general warming tendency during much of the autumn-winter period, with statistically significant increases in selected monthly maximum temperatures, particularly November and February, and widespread increases in minimum temperatures. Precipitation exhibited high interannual variability and declining tendencies during several months, notably November and December, although October and March showed different or weaker trajectories. These climatic changes occurred concurrently with substantial reductions in vegetable production and cultivated area for several crops, most notably potatoes and tomatoes. Correlation analyses identified associations between temperature or precipitation anomalies and selected crop indicators; however, these relationships should not be interpreted as causal because agricultural production is also strongly influenced by irrigation availability, market conditions, land-use change, technology, labour, policy and farm management. The findings nevertheless indicate increasing climatic exposure of Maltese agriculture and support adaptation based on improved water-use efficiency, rainwater harvesting and storage, soil-moisture conservation, climate-resilient cultivars, adjusted crop calendars, diversification and climate-informed agricultural advisory services. The study provides a national-scale baseline for subsequent crop- and farm-level analyses of climate risk in Malta.

Understanding temporal dynamics of meteo-marine parameters at the Ċirkewwa Marine Park

Thu, 01 Jan 2026 00:00:00 GMT

Title: Understanding temporal dynamics of meteo-marine parameters at the Ċirkewwa Marine Park Abstract: This study investigates the temporal variability of key meteo-marine parameters within the Ċirkewwa Marine Park (ĊMP), Malta, through the integration of in-situ observations and modelled datasets. This site was selected due to its ecological significance and exposure to dynamic coastal processes, providing an appropriate setting to assess atmosphere-ocean interactions. Particular emphasis is placed on subsurface sea temperature variability and the extent to which model outputs accurately represent observed conditions. A multi-method approach was employed, involving the deployment of temperature loggers at depths of 5 m, 10 m, 15 m, and 20 m to collect high-resolution hourly measurements. Following the loss of the 5 m logger, analyses were based on observations from the remaining depths. These measurements were complemented by meteorological parameters, including air temperature, wind speed, and direction, alongside model outputs from the Copernicus Marine Environment Monitoring Service (CMEMS). The combined datasets were analysed to evaluate temporal trends, vertical stratification, and the influence of atmospheric forcing on water column dynamics. Results demonstrate clear seasonal variability, with temperatures increasing from early summer to a peak in September, followed by a gradual decline into autumn. A persistent vertical gradient was observed, indicative of stratified conditions, although episodic wind events exceeding 5 m/s promoted short-term mixing and partial disruption of the thermocline. While modelled and observed datasets showed general agreement in near-surface trends, discrepancies became increasingly pronounced with depth, with CMEMS consistently underestimating deeper temperatures. This highlights limitations in the capacity of models to resolve fine-scale coastal processes and vertical structure. However, the study is constrained by its relatively short temporal coverage and limited spatial resolution, which restrict the generalisability of the findings. Despite these limitations, it provides a valuable high-resolution baseline for the ĊMP and underscores the importance of sustained, multi-depth monitoring and rigorous model validation to enhance understanding of coastal dynamics and inform effective marine management strategies. Description: B.Sc. (Hons)(Melit.)

Chemical characterization and in vitro gas production kinetics of alternative feed resources for small ruminants in the Maltese islands

Sun, 01 Jan 2023 00:00:00 GMT

Title: Chemical characterization and in vitro gas production kinetics of alternative feed resources for small ruminants in the Maltese islands Authors: Pastorelli, Grazia; Simeonidis, Kalliroi; Faustini, Massimo; Le Mura, Angelo; Cavalleri, Mariagrazia; Serra, Valentina; Attard, Everaldo Abstract: The ever-increasing human population, the problem associated with climate change and recent crises—COVID-19 disease and trade conflicts—all impacted on the availability and cost of animal feed raw materials. This is clearly visible in realities which heavily rely on importation such as islands and small states, where producers involved in the agricultural sector were strongly affected by the sharp increase in prices. To deal with these global issues, alternative resources are perceived to replace conventional ingredients. This work aimed at assessing the nutritive value of different resources (sheep feed, mature carob, Maltese bread, wild asparagus, prickly lettuce, and loquat) for small ruminants present in the Maltese Islands, analyzing their chemical composition, gas production kinetics and antioxidant properties. In general, the variation in chemical composition resulted in different rumen fermentation kinetics (p < 0.007). The ratio between GP-24 h and GP-48 h was higher in Maltese bread than other substrates; loquat, prickly lettuce and wild asparagus showed lower fermentation kinetics in accordance with their high NDF and ADF contents. The antioxidant activity may be partially related to the polyphenolic content that was higher in wild asparagus, prickly lettuce and loquat. All feed characteristic confirmed their potential to be included as ingredients in ruminant diets and as a source of fiber.

Formulation of plant-based pesticides

Thu, 01 Jan 2026 00:00:00 GMT

Title: Formulation of plant-based pesticides Abstract: The increasing reliance on synthetic pesticides in modern agriculture is raising concerns regarding environmental contamination, biodiversity loss, pesticide resistance, and risks to human health. Because of this there is an increasing interest in botanical pesticides as a sustainable alternative to synthetic pesticides. Because of its warm Mediterranean climate, Malta faces this challenge in various crops, particularly in the production of brassica crops such as the cauliflower. which are economically important crops affected by caterpillar pests. This study evaluated the potential of Nicotiana glauca-based formulations as botanical insecticides through an integrated assessment of biological efficacy, toxicity, and residue persistence. The research focused on cauliflower (Brassica oleracea var. botrytis), one of Malta's most commonly cultivated brassica crops, and targeted two major pest species, the Small White Butterfly (Pieris rapae) and the Large White Butterfly (Pieris brassicae), both of which can cause substantial crop damage and economic losses to farmers. Three complementary approaches were employed: an in vivo caterpillar assay, a residue analysis in cauliflower tissues using UV-Vis spectrophotometry, and a brine shrimp lethality assay (BST) with probit analysis for LC₅₀ determination. The caterpillar study demonstrated that all treatments, including Nicotiana glauca (Ng) and its combination with garlic (T), significantly reduced survival over time. Although the synthetic insecticide (E) induced faster initial mortality, botanical treatments achieved comparable lethality within the experimental period. The BST assay confirmed dosedependent toxicity for all treatments, with strong linear probit-log dose relationships (R² = 0.88-0.99). The combined treatment (T) exhibited the highest toxicity (LC₅₀ = 19.82 µg/mL), followed by Ng (29.60 µg/mL), while nicotine showed the lowest toxicity (78.86 µg/mL). Statistical analysis revealed significant differences in both slopes and intercepts of doseresponse curves, indicating distinct toxicological profiles. Residue analysis showed that alkaloid-related compounds from Nicotiana glauca degraded rapidly in cauliflower tissues, with half-lives of approximately 1 day and DT₉₀ values around 3 days. In contrast, the synthetic insecticide exhibited significantly greater persistence (DT₉₀ ≈ 10 days). These findings indicate that botanical treatments provide strong biological activity while minimising long-term residue accumulation. The integration of results demonstrates that Nicotiana glauca-based formulations are effective and rapidly degrading bioinsecticides. However, the measurable toxicity of the control formulation highlights the importance of considering formulation effects. Overall, the study supports the potential of botanical pesticides as environmentally favourable alternatives to synthetic insecticides, while emphasising the need to balance efficacy, persistence, and formulation in their development. Description: M.Sc.(Melit.)