Part 2 of the Agricultural Research Programme is focused on the 10th Citrus Research Symposium. The Centre for Biological Control (CBC) was represented at this symposium by a contingent of 12 members comprising of student and professional researchers. It took place at Champagne Sports Resort, in the Drakensberg from the 19-22 of August. The symposium was attended by a number of people from both agricultural and research backgrounds such as independently owned citrus farmers, as well as Citrus Research International (CRI), Agricultural Research Council (ARC) and Stellenbosch University to list a few.

The Citrus Symposium is held every two years where researchers can inform farmers of helpful ongoing research. This year, much attention was focussed on Huanglongbing, or citrus greening disease (HLB). The disease-causing bacteria is spread by the citrus psyllid but the bacteria can also be spread via tree grafting or the movement of infected plant material. Citrus greening has not yet reached South Africa, but the discussions weren’t about if it will come, rather when. Citrus greening destroyed Florida’s crop, and research has been conducted to prevent and reduce HLB when it arrives in SA.

The CBC research is focussed on the citrus phytosanitary pest, false codling moth, which is endemic to southern Africa. If this pest is present in fruit exported to the EU, the entire consignment can be rejected resulting in immense monetary loss. It is also imperative that this pest is controlled if South Africa wants to remain within the EU market.  Different control aspects of FCM is studied at the CBC, with control means varying from entomopathogenic microorganisms (fungi, nematodes and virus) to post-harvest treatments and the recent trend of orchard netting. Members of the CBC contributed to the symposium by conducting eight presentations and two posters. This symposium was attended thanks to the support from Citrus Research International, the Centre for Biological Control and Citrus Academy.

CBC Citrus Symposium Presentations:

• False codling moth population ecology in citrus orchards: the influence of orchard age: Sonnica Albertyn (15 minutes)
• Development of UV-resistant CrleGV-SA formulations for use as an enhanced biopesticide for FCM control on citrus: Patrick Mwanza (15 minutes)
• Yeast-baculovirus synergism: Investigating mixed infections for improved management of the false codling moth: Marcel van der Merwe (15 minutes)
• The development of genetically modified (GM) baculoviruses for improved control of false codling moth: Michael D. Jukes (15 minutes)
• Response to the first case of citrus leprosis-N in South Africa: Wayne Kirkman (15 minutes)
• Postharvest detection of false codling moth in citrus fruit by volatile emissions: Wayne Kirkman (15 minutes)
• A novel method for inhibiting mating of the false codling moth on citrus in South Africa: 7-vinyl-Decyl Acetate: Wayne Kirkman (Poster)

Marcel van der Merwe during his presentation at the Citrus Symposium

A wide variety of citrus to sample