Moroccan Citrus Research Articles

Effect of gamma-irradiation on phenolic compounds and phenylalanine ammonia-lyase activity during storage in relation to peel injury from peel of Citrus clementina hort. Ex. tanaka.

The influence of gamma-irradiation on the content of phenolic compounds was evaluated on Moroccan Citrus fruits (Citrus clementina Hort. ex. Tanaka) treated at a mean dose of 0.3 kGy and stored for 49 days at 3 degrees C. The results show that irradiation has enhanced the synthesis of total phenolic compounds and is correlated with phenylalanine ammonia-lyase activity (PAL) during storage. Accumulation of phenolic compounds in cells is demonstrated and may be explained by the enhancement of PAL activity. HPLC/UV (diode array detector) analysis demonstrated that hesperidin was the major flavanone and nobiletin and heptamethoxyflavone were the major polymethoxylated flavones. Hesperidin is also the major phenolic compound in clementines. Irradiation stimulates the biosynthesis of hesperidin after 14 days of storage, corresponding to the maximum of PAL activity. p-Coumaric acid was also identified, and its content was particularly high in irradiated fruits after 49 days of storage. Accumulation of flavonoids and p-coumaric acid could be related to a better resistance. The percentage of losses due to peel injury "pitting" during storage was between 1 and 5% after 49 days of storage. The connections between irradiation, enzyme activity, phenolic content, and peel injury are briefly discussed.

Selection of pesticides for integrated pest control programmes in Moroccan citrus

AbstractThe effect of several acaricides and aphicides were tested on the nymphs and eggs of the scale parasite Aphytis melinus infesting Aonidiella aurantii and Aspidiotus hederae; several compounds can be recommended for deployment in integrated control programmes in citrus.ZusammenfassungZur Auswahl von Pestiziden für ein integriertes Schädlingsbekämpfungs‐Programm im marokkanischen Citrus‐AnbauEs wurden verschiedene Pestizide hinsichtlich ihrer Wirkung auf die Schildläuse Aonidiella aurantii und Aspidiotus hederae sowie ihres Eiparasiten Aphytis malinus getestet. Dabei erwiesen sich einige Präparate für ein Programm der integrierten Schädlingsbekampfung im Citrusanbau Marokkos als besonders geeignet.