Studies on the fungal dieback disease on some fruit trees in Zalingei Locality, Darfur, Sudan

The study was carried out at Zalingei locality, Central Darfur State, in the year 2017, to determine the fungal pathogens that causing dieback disease to the fruit trees, and to study the effect of aqueous Neem extract (Azadirachta indica) on growth of the identified fungal pathogens under laboratory conditions. Experimental approach and descriptive analytical method were used. Primary data were collected using the questionnaires, laboratory experiment, field survey and personal interviews. Results revealed that there are two types of fungi (Fusarium oxysporum and Rhizoctonia sp.) which causing dieback disease in the study area. The highest dieback disease incidence recorded was found to be: 5.0% (In Mango), 4.3% (In Guava) and 2.5% (In Citrus), in Zalingei, Orukum and Qere area, respectively. Results showed that the water extract of neem seeds had an inhibitory effect on growth of both Fusarium oxysporum and Rhizoctonia sp. There was no significant difference between the effect of different concentrations 12.5%, 25%, and 50% of aqueous neem extracts on dieback fungal causal agents growth but in case of Fusarium oxysporum growth of the colony was reduced by 21.0%, 38.57%, and 54.47% respectively, while in case of Rhizoctonia sp., it reduced by 25%, 51.10%, and 51.34% respectively. The study suggested to raise the awareness of the farmers about the dieback disease through workshops, trainings and control campaigns, Additional studies for others substitutes and additional studies on other Dieback disease causes.