En savoir plus

Investigating the colonization of Trichoderma in grapevine nursery vines for improved management of black foot disease

Abstract

Black foot disease (BFD) is one of the main fungal diseases associated with young grapevine decline. Apart from hot water treatment of dormant nursery vines, no treatment is available to prevent nursery plants from becoming infected with BFD pathogens after planting.

Trichoderma species is well-known for their biological control and plant growth promotion abilities. In the past variable success of colonization of Trichoderma spp. were found when applied to nursery vines. Therefore different methods of application of Trichoderma atroviride were tested on commercially planted nursery vines.

One hundred graftlings were used per treatment, replicated five times and repeated over two seasons. To assess the efficacy of different commercially available Trichoderma products another trial was carried out on grapevine nursery vines post callusing. One hundred graftlings were used per treatment, replicated four times and repeated over two seasons. For both seasons the trials were uprooted after 7 months and isolations made from the base of the vine and the roots. Trichoderma and black foot pathogens were recorded.

When comparing tissue parts, the base of the vine and top part of roots had significantly higher Trichoderma colonization than the middle and bottom parts of the roots. Significantly less black foot pathogens were isolated from the base compared to the roots, indicating that the higher presence of Trichoderma atroviride in these tissues had an inhibiting effect. The different application methods clearly showed that dipping of basal ends in the dry formulation consistently gave the highest colonization. The 1 hour soak of bases of vines was not effective. The field drenching was significantly less effective than the dry dip application.

These results provide valuable insights into the application of Trichoderma products in grapevine nurseries.

W.J. van Jaarsveld 1, F. Halleen 1,2, L. Mostert 1

• 1 Department of Plant Pathology, University of Stellenbosch, Private Bag X1, Matieland, 7602, South Africa;
• 2 Plant Protection Division, ARC Infruitec-Nietvoorbij, Private Bag X5026, Stellenbosch, 7599, South Africa.

Contact : wynandvj@sun.ac.za