THE EFFECT OF IRRIGATION DOSES ON THE PRODUCTIVITY OF Citrus clementina variety “Fina Berkane”, A VARIETY OF CLEMENTINE PRODUCED IN TRIFFA PLAIN, NORTH EASTERN MOROCCO

Morocco is a Mediterranean country with an economy based on exporting agricultural products mainly to Europe. However, the ongoing climate change characterized by the frequency and the intensity of drought, along with the regularity of the rainfall is undeniably affecting the productivity of major agricultural products in Morocco. Citriculture is one of the key pillars of agricultural products in Moroccan conditions and the productivity of citriculture is tightly related to water management. To reduce this dependency under climatic change, a pilot study, over three years, has been launched to assess the effect of water stress on the production of clementine (Citrus clementina 'Berkane Clementine'). This study was carried out on the clementine, variety "Fina Berkane" at the Triffa plain, Northeastern Morocco. This variety was grafted on Volkameria rootstock with a density of 3m x 6m. Experimental variety was planted during October 2012, in loam-clay soil equipped with a drip irrigation system. Four doses of water irrigation (60%, 80%, 100%, and the conventional irrigation dose⩾120%) were tested based on the real water demand of the studied plant. Throughout the three-year monitoring, the effect of used water amount on the various parameters including yield, fruit size, and fruit quality have been studied. Results of the study revealed that the treatment 100% ETc provided a high number of fruits, yield, and a good quality ratio. It was also well reported that adopting a dose of 80% ETc could save a significant amount of irrigation water (more than 40% ETc) compared to the conventional irrigation dose (⩾120% ETc) without significantly affecting either the yield or the desired caliber profile (marketable standard)

Variations morphologiques et métabolisme glucidique chez Streptococcus salivarius subsp. thermophilus CNRZ 368

La présente étude a porté sur trois variants de Streptococcus salivarius subsp. thermophilus CNRZ 368 distincts par la morphologie macroscopique des colonies. Au niveau microscopique les cellules des variants OM, D31 et D12 se distinguent par la forme et la longueur des chaines qu'elles constituent. De point de vue métabolisme et physiologie, l'étude du métabolisme glucidique, de la croissance bactérienne et le profil électrophorétique des protéines solubles démontre que les trois variants étudiés sont apparentés. Le suivi de l'évolution de la DO, de l'acidification du milieu de culture et de la production de l'ATP confirme que le variant OM a une activité métabolique du lactose plus importante que celles des variants D12 et D3!. À l'inverse, le variant OM possède une activité métabolique du glucose plus faible que celles des deux autres variants