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Pears have great importance in Tunisia for their desirable taste and commercial value. Until 2012, the pear cultivation was protected against fire blight by the application of a rigorous quarantine system. Fire blight, caused by Erwinia amylovora, was outbreak in Tunisia in the spring of 2012 and has spread rapidly through the most important pear growing regions destroying several hundred hectares of pear plantations. Therefore, the total pear production has decreased from 60,000 metric tons in 2011 to less than 20,000 metric tons in 2016. In this study, collected data of pear culture and surveys were carried out during four years (2012)(2013)(2014)(2015)(2016) in the main pear growing areas to evaluate the current situation of the disease in the country particularly in the damaged regions of the lower valley of Medjerda (Manouba, Ben Arous, Bizerte, and Beja). Samples collected from symptomatic trees were processed for the isolation and identification of the causal agent using microbiological and molecular techniques. The results indicate that the disease had destroyed more than 5500 hectares among a total of 8400 hectares of pear plantations area. Both provinces Manouba and Ben Arous were the most affected by fire blight disease resulting in the eradication of 350 and 325 hectares of pear plantations, i.e., 100% and 98% of the total infected area, respectively. All control attempts, including sanitary measures, the application of mineral oil and copper, growth regulators and biological control have failed to limit the spread of the disease. The presence of pathogen in the prospected regions was confirmed by pathogenicity and molecular tests, which are compatible with the symptoms observed throughout the surveys. The pear cultivation in Tunisia is threatened by fire blight due to the restriction tolerance of the available varieties and the climatic conditions favoring the staggered flowering of the species. Quarantine measures must be implemented to prevent the spread of this disease in a new disease-free areas.

Energy conservation in buildings has been the focus of many studies since nearly one-third of global energy consumption is due to buildings. Phase change material (PCM) technology promises to be an attractive solution for energy saving in buildings since it is a passive and effective technology, as demonstrated in the literature. Therefore, this study focuses on the energy-saving performance of PCM-integrated buildings located in a Mediterranean climate to reveal their energy-saving potential. PCM is integrated both in external or internal south walls and roofs of buildings under four different climatic conditions. EnergyPlus, which is a well-known building simulation software, is adopted for building thermal analyses. The effects of melting temperature, location of PCM layer in the wall, thickness of PCM layer, type of envelope (wall or roof), and PCM double-layer system in the wall are investigated. The corresponding energy savings and CO2 emission reductions are obtained for the considered cases. The results showed that up to 41.6% reduction in energy demand can be obtained depending on the PCM application. Besides, PCM with a low melting temperature (21 °C) favored heating energy savings, while PCM with a high melting temperature (29 °C) favored cooling energy savings. Moreover, the double-layer PCM system provided higher energy savings than the single-layer PCM system, especially in warm and arid regions (Sousse and Tozeur).