WG4 Meeting COST Action FA1303 Sustainable control of GTDs Logroño, Spain, 6 & 7 October 2016 Management of GTDs in nurseries and in the vineyard Biocontrol agents Biological control of Grapevine Trunk Diseases: A South African perspective Francois Halleen & Lizel Mostert
Stellenbosch, South Africa
ARC Infruitec-Nietvoorbij The Fruit, Vine and Wine Research Institute of the Agricultural Research Council (ARC)
University of Stellenbosch
Outline Biocontrol of GTDs in vineyards (Pruning wound protection) Biocontrol of GTDs in nurseries
Background: Biocontrol Agents Perception: Not as effective as chemicals Unreliable Application problems (paint, backpack sprayer, labour..)
Pruning wound protection with Biological Control Agents Typical questions from farmers: Can I use Trichoderma if I spray chemicals? How long does it take to grow / colonise the wound? How deep does it grow? Were does it grow? What happens to the pathogens? How long does the Trichoderma survive within the plant? Re-apply? Can I use Trichoderma on all my cultivars (various pruning practices ) How soon after pruning must Trichoderma be applied? Etc..
Commercial Products T. harzianum T. virens T. atroviride (Excalibur Gold) T. fertile (Trichoplus) T. atroviride T. harzianum (Biotricho) T. harzianum (Awegenic Tri-cure) T. harzianum T. atroviride (MT1) T. atroviride (USPP-T1)
Biocontrol of GTDs in vineyards Pruning wound protection Bacillus subtilis / Trichoderma spp. Several products registered in SA based on Trichoderma spp. Usually only registered against Eutypa lata
Trichoderma mode of action Competitive antagonism Antibiosis Myco-parasitism Induce host natural defence (grapevines?) Efficacy of Trichoderma is strain dependant Photos: C. Kotze
Hyphal adhesion Coiling Disintegration of pathogen mycelium Penetration of pathogen mycelium Kotze et al., 2011 Phyt Mediterranea 50: S247-S263
Effect of Trichoderma crude extract on trunk pathogens Neofussicoccum parvum Diplodia seriata PDA + Trichoderma crude extract Control (PDA) PDA + Trichoderma crude extract Hyphal inhibition by 10 µl of extract Extract fungitoxic
Quantification - LC-MS/MS 6-Pentyl α-pyrone (6PP)
Effect of 6PP on mycelial growth Mutawila et al., 2016 Plant Pathology 65: 104-113
Growth of Trichoderma & Eutypa in pruning wounds 90 days after pruning 35 Cab. Sauvignon 35 30 Sauvignon blanc 30 Cab. Sauvignon Sauvignon blanc Isolation depth (mm) 25 20 15 10 Isolation depth 25 20 15 10 5 5 0 Xylem Pith Xylem Pith 0 Xylem Pith Xylem Pith T. harzianum dsred E. lata Gfp T. harzianum dsred E. lata Gfp Single inoculation Dual inoculation Trichoderma grew deeper into the wood in presence of Eutypa sense / recognize the pathogen. Pathogen almost gone in Sauvignon blanc. Trichoderma grew in pith in presence of Eutypa. Mutawila et al., 2011 Phytopathologia Mediterranea 50: S46-S60
Trichoderma pruning wound protection: Results from various field trials
C. blanc Red Globe Merlot Shiraz C. Sauvignon T. Seedless Victoria Prime Pinotage S. blanc Colombar Percent (%) Correlation between Trichoderma incidence & pathogen reduction 80 70 Pathogen Reduction (%) Trichoderma Incidence (%) 60 50 40 30 20 10 0 r = 0.88 P < 0.01 r = 0.62 P < 0.01 r = 0.58 P < 0.01 r = 0.54 P = 0.01 r = 0.62 P < 0.01 r = 0.55 P = 0.01 r = 0.29 P = 0.22 r = 0.70 P < 0.01 r = - 0.12 P = 0.62 r = 0.26 P = 0.26 r = 0.54 P = 0.01 Trichoderma incidence + correlated with pathogen reduction What is the cause of variation in Trichoderma incidence in the compatible cultivars? Could the vine physiological state have an effect? Mutawila et al., 2011 Phytopathologia Mediterranea 50: S264-276
Halleen et al., 2010 South Afr. J. Enol & Vitic 31: 125-132 Incidence of the pruning wound invader Eutypa lata isolated from Cabernet Sauvignon pruning wounds treated with chemical and biological treatments directly after pruning and inoculated with 1000 E. lata ascospores 24h after pruning. Treatment Control (+) Bacillus Eco77 Eco77(+) Vinevax Biotricho Benomyl Flusilazole Kontrole Incidence (%) Eutypa lata 50 a 49 a 25 b 34 ab 30 b 38 ab 4 c 3 c 0 c KBV (P=0.05) 19.77
Incidence of Eutypa lata isolated from pruning wounds 8 months after the fresh wounds were treated with chemical and biological treatments and challenged 7 days later by spray-inoculation with E. lata Treatment Eutypa lata (%) Bacillus subtilis Benomyl Biotricho Eco77 USPP-T1 USPP-T2 Vinevax Water (control) 10.71 b 19.58 d 15.00 c 10.65 b 9.13 b 11.00 bc 8.17 b 37.50 e LSD (P 0.05) Kotze et al., 2011 Phytopathologia Mediterranea 50: S247-S263
OPTIMISATION OF THE TIME OF APPLICATION OF TRICHODERMA BIO- CONTROL AGENTS
OPTIMISATION OF THE TIME OF APPLICATION OF TRICHODERMA BIO- CONTROL AGENTS Cultivars Chenin blanc Early pruning Cabernet Sauvignon Late pruning Treatments USPP-T1 (T. atroviride) Eco 77 (T. harzianum) Water Time of wound treatment after pruning 0 hrs (within 30 min) 6 hrs 24 hrs 48 hrs 96 hrs
Effect of application time on Trichoderma incidence in Cab. Sauvignon 2011 2012 Longer window of application in July (up to 96h) Lower incidence in August due to faster wound healing 6 hr application has high incidence at both pruning times Mutawila et al., 2016 Australian Journal of Grape and Wine Research 22: 279 287
Effect of time of application on Trichoderma incidence in Chenin blanc 2011 2012 Lower incidence in July, 2011 (0 hrs) due to wound sap at dormancy break Mutawila et al., 2016 Australian Journal of Grape and Wine Research 22: 279 287
OPTIMISATION OF THE METHOD OF APPLICATION OF TRICHODERMA BIO- CONTROL AGENTS
Method of Application
Effect of Application Method Artificial pathogen inoculation Mutawila 2014, PhD dissertation, University of Stellenbosch
Effect of Application Method Natural pathogen inoculum
Biocontrol of GTDs in nurseries
Integrated Management: Nurseries Pruning wound protection Mother vines Harvesting of graft cuttings Benomyl or Carbendazim Cold storage Farmer HWT HWT Sporekill Grafting Class Uplift plants Trichoderma Trichoderma Callusing Fosfonate! Plant
Halleen & Fourie, 2016 South Afr. J. Enol & Vitic 37(2) In Press
Halleen & Fourie, 2016 South Afr. J. Enol & Vitic 37(2) In Press
Halleen & Fourie, 2016 South Afr. J. Enol & Vitic 37(2) In Press
Conclusion Know your biocontrol agent Understand the system where you want to apply it Trichoderma as biocontrol agent has a significant role to play in pruning wound protection against GTD s Trichoderma as biocontrol agent could play a significant role in an integrated programme to control GTD s in grapevine nurseries.
Acknowledgements